Classifications

• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
  • C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
  • C23G1/14—Cleaning or pickling metallic material with solutions or molten salts with alkaline solutions
  • C23G1/20—Other heavy metals
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
  • C23C2/04—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the coating material
  • C23C2/06—Zinc or cadmium or alloys based thereon
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
  • C23C2/26—After-treatment
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
  • C23C2/34—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the shape of the material to be treated
  • C23C2/36—Elongated material
  • C23C2/40—Plates; Strips
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
  • C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
  • C23C22/06—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
  • C23C22/07—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing phosphates
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
  • C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
  • C23C22/06—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
  • C23C22/24—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing hexavalent chromium compounds
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
  • C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
  • C23C22/06—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
  • C23C22/34—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing fluorides or complex fluorides
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
  • C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
  • C23C22/06—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
  • C23C22/40—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing molybdates, tungstates or vanadates
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
  • C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
  • C23C22/06—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
  • C23C22/40—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing molybdates, tungstates or vanadates
  • C23C22/44—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing molybdates, tungstates or vanadates containing also fluorides or complex fluorides
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
  • C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
  • C23C22/06—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
  • C23C22/48—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 not containing phosphates, hexavalent chromium compounds, fluorides or complex fluorides, molybdates, tungstates, vanadates or oxalates
  • C23C22/53—Treatment of zinc or alloys based thereon
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
  • C23C22/73—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals characterised by the process

Definitions

• the present invention relates to a method for cleaning and/or anti-corrosion pretreatment of a large number of components in series, in which the components of the series are at least partially composed of galvanized (ZM) steel.
• the components go through a treatment stage to improve the wettability of the galvanized (ZM) steel surfaces, in which at least the surfaces of the galvanized (ZM) steel of the components are brought into contact with an aqueous agent which contains at least one builder which is a salt of a Lewis acid-base pair in which the Lewis acid is selected from Li + , Na + , K + , Ca 2+ , Mg 2+ or Al 3+ and the Lewis base is selected from anions of a polyprotic Bronsted acid.
• the total concentration of builders in the wetting treatment step is at least 0.4 mol/kg.
• the weight savings associated with the smaller layer thickness means that hot-dip galvanized (ZM) steel is a comparatively resource-saving strip material for the production of lightweight bodywork, so that the surface area of this material on the bodywork, in addition to the surface area of other light metals such as aluminum, can be used in the automotive production will continue to increase.
• ZM hot-dip galvanized
• the metallic coating produced on hot-dip galvanized (ZM) steel strip contains approximately 1.5 to 8% by weight of the metals aluminum and magnesium, with the proportion of magnesium being at least 0.2% by weight.
• the basic suitability of these coatings to be formed, pretreated and coated in conventional processes established in the state of the art is generally recognized and proven ( Characteristic Properties 095 E, "Continuously Hot-Dip Coated Steel Strip and Sheet", Chapters 8 and 10, Edition 2017, vealism Stahl ), but due to the special composition of the coating and the native oxide layer, there are special features that must be taken into account, especially during cleaning and pre-treatment, for a coating result that is as homogeneous and reproducible as possible and thus optimal corrosion protection behavior or the desired surface functionality.
• 2016/0010216 A1 also describes that the reduction of magnesium oxide in the near-surface oxide layer of hot-dip galvanized (ZM) strip steel is advantageous for the anti-corrosion pretreatment and proposes a treatment of the strip steel that accompanies or follows the degreasing with a neutral or alkaline aqueous composition containing a complexing agent for magnesium before.
• the proposed complexing agents are selected from organic acids or their salts and preferably selected from glycine and diphosphoric acid.
• the present invention sets itself the task, on the one hand, of optimally conditioning the surface formed by hot-dip galvanized (ZM) steel for subsequent cleaning and anti-corrosion pretreatment and, on the other hand, of ensuring the wettability of these surfaces in the series treatment of a large number of components with uniform quality, so that a subsequent wet-chemical treatment step, which can be a cleaning step and/or an anti-corrosion pretreatment, can be carried out with consistent success.
• ZM hot-dip galvanized
• the order of the treatment steps i)-iii) is decisive for the success of the invention and initially includes a cleaning step, which serves to remove coarse soiling from the components of the series and to provide an easily wettable surface and is therefore also referred to below as pre-cleaning.
• This pre-cleaning follows with or without an intermediate rinsing and/or drying step, preferably with an intermediate rinsing step but without a drying step, the treatment step in which at least those surfaces of the component that are galvanized (ZM) steel surfaces are treated with the aqueous agent containing at least one builder in be contacted.
• Process step ii) results in permanent wettability of the (ZM) surfaces, so that the surfaces are optimally conditioned for a subsequent cleaning and/or anti-corrosion surface treatment.
• Process step ii) is therefore also referred to below as conditioning.
• the conditioning in the process according to the invention is followed by the process steps required for the application of an anti-corrosion coating, with the application of the coating either being first subjected to a cleaning step or an anti-corrosion pretreatment being carried out immediately, which is ultimately the preferred variant for process-economy considerations.
• a specific anti-corrosion pre-treatment usually also requires a coordinated upstream specific cleaning, so that in such a case the conditioning is first followed by cleaning and then a downstream anti-corrosion pre-treatment.
• process step iii) in the process according to the invention follows process step ii) directly, ie without an intermediate drying step, in particular without an intermediate drying or rinsing step.
• a rinsing step within the meaning of the present invention refers to a process that is solely intended to remove active components from an immediately preceding wet-chemical treatment step, which are dissolved in a wet film adhering to the component, by means of a rinsing solution from the surface of the component as far as possible, without the active components to be removed are replaced by others.
• Active components in this context are the components dissolved or dispersed in the aqueous phase, which are consumed through contact with the components and their proportion and concentration in the respective aqueous solution is therefore active in the course of the series treatment, i.e. by metering in using devices provided for this purpose, via a value specified in the process must be maintained.
• a drying step within the meaning of the present invention refers to a process in which the surfaces of the components that have a wet film are to be dried with the aid of technical measures.
• a treatment of components in series is present when a large number of components are brought into contact with the treatment solutions provided in the respective treatment steps i)-iii) of the method according to the invention and usually held in system tanks, the contacting of the individual Components one after the other and thus separated in time.
• a system tank is a container in which the respective treatment solution is located in series for the purpose of cleaning and/or anti-corrosion pre-treatment, but not necessarily the place of contact. In this way, a portion of the treatment solution stored in a system tank that is sufficient to bring the (ZM) surfaces of the component into contact can be fed out of the system tank and applied to the component separately from the system tank, for example in a spray or fogging chamber.
• Treatment stage i) serves to remove soiling, in particular drawing, forming, rolling and anti-corrosion oils, from the component surfaces.
• the (ZM) surfaces of the components of the series have a carbon coating of less than 0.50 g, particularly preferably less than 0.10 g of carbon per square meter of the (ZM) after going through process step i). surface of the components.
• the layer of carbon remaining on the (ZM) surfaces of the components can be determined by means of pyrolytic decomposition.
• a representative component section with a defined area is brought to a substrate temperature of 550°C (PMT) in an oxygen atmosphere and the amount of carbon dioxide released is measured quantitatively using an infrared sensor as an amount of Carbon detected, for example, using the LECO® RC-412 Multiphase Carbon Determinator analyzer (Leco Corp.).
• the cleaning preceding the surface conditioning in process step ii) is carried out using alkaline aqueous solutions containing surfactants.
• surfactants in the context of the present invention are surface-active organic compounds which, for their surface activity, are composed of a hydrophilic and at least one lipophilic molecule component or of a lipophilic and at least one hydrophilic molecule component, the molecular weight of the surface-active organic compound not exceeding 2000 g/mol.
• Nonionic surfactants which are selected from alkoxylated alkyl alcohols, alkoxylated fatty amines and/or alkyl polyglycosides, particularly preferably from alkoxylated alkyl alcohols and/or alkoxylated fatty amines, particularly preferably from alkoxylated alkyl alcohols, are preferred in terms of substance in the pre-cleaning of the process according to the invention.
• the alkoxylated alkyl alcohols and/or alkoxylated fatty amines are preferably end-capped for a defoaming effect, particularly preferably with an alkyl group which in turn preferably has no more than 8 carbon atoms, particularly preferably no more than 4 carbon atoms.
• alkoxylated alkyl alcohols and/or alkoxylated fatty amines as nonionic surfactants for pre-cleaning in the process according to the invention which are ethoxylated and/or propoxylated, the total number of alkylene oxide units preferably not being greater than 16, particularly preferably not greater than 12. particularly preferably not greater than 10, but particularly preferably greater than 4, particularly preferably greater than 6.
• alkoxylated alkyl alcohols and/or alkoxylated fatty amines are preferred as nonionic surfactants in the pre-cleaning of the process according to the invention, the alkyl group of which is saturated and preferably unbranched, the number of carbon atoms in the alkyl group preferably being greater than 6, particularly preferably at least 10, particularly preferably at least 12, but preferably not greater than 20, particularly preferably not greater than 18, particularly preferably not greater than 16.
• alkoxylated alkyl alcohols and / or alkoxylated fatty amines are preferred whose lipophilic alkyl group comprises at least 10 carbon atoms, more preferably at least 12 carbon atoms, the longest carbon chain in the alkyl group consisting of at least 8 carbon atoms and an HLB value in the range from 12 to 16 realized.
• nonionic surfactant to be used in the precleaning which is selected from alkoxylated alkyl alcohols, alkoxylated fatty amines and/or alkyl polyglycosides, is the cloud point determined according to DIN 53 917 (1981), which is preferably above 20° C., but particularly preferably below the application temperature of the pre-cleaning is, particularly preferably more than 5 ° C, but not more than 10 ° C below the respectively chosen application temperature of the aqueous agent for the pre-cleaning.
• the proportion of surfactants, in particular nonionic surfactants, in the aqueous cleaning solution of process step i) is preferably above 0.01% by weight, particularly preferably above 0.10% by weight, particularly preferably above 0.20% by weight. -%, but preferably not more than 2.00% by weight, based on the cleaning solution. If in the following the proportion of a compound or substance as a percentage by mass is given, in the absence of other specifying information, the respective solution or the respective means is always the reference value.
• the application and thus the contacting of the aqueous cleaning solution preferably takes place at at least 30.degree. C., particularly preferably at at least 40.degree. C., but preferably below 60.degree.
• the cleaning solution of the pre-cleaning can be brought into contact with the components of the series by means of application types established in the state of the art. These include, in particular, dipping, rinsing, spraying and/or spraying, application by dipping and/or spraying being preferred.
• the pH value of the aqueous cleaning solution is set alkaline in the method according to the invention for sufficient pre-cleaning in which the components are effectively freed from oil-based soiling, but the pH value is preferably not above 12 to mitigate the stripping of the metallic substrates of the components ,0.
• the method according to the invention is to be used specifically in automotive production, in which hot-dip galvanized (ZM) strip steel is used as the production material and other materials such as steel and aluminum are used, so that the bodies produced in series usually consist of a mix of different metallic materials.
• ZM hot-dip galvanized
• the pH value of the cleaning solution can be selected so that the least possible pickling effect is achieved.
• it can preferably apply to the aqueous cleaning solution that its pH value is not above 11.5, particularly preferably not above 10.5, but a pH value of at least 8.0 is set for the degreasing effect.
• Treatment level ii) - conditioning
• Treatment stage ii) serves to make the surfaces of the component, which are formed from hot-dip galvanized (ZM) steel, reliably and permanently wettable for subsequent cleaning and/or pre-treatment stages, in order in this way to achieve a uniform and, during the treatment of components in To ensure series reproducible surface finish and corrosion protection for the inventively treated components.
• ZM hot-dip galvanized
• the conditioning of the surfaces of (ZM) to be carried out in treatment stage ii) requires them to be brought into contact with an aqueous agent containing one or more builders, which is a salt of a Lewis acid-base pair in which the Lewis acid is selected from Li + , Na + , K + , Ca 2+ , Mg 2+ or Al 3+ and the Lewis base is selected from anions of a polyprotic Bronsted acid.
• an aqueous agent containing one or more builders which is a salt of a Lewis acid-base pair in which the Lewis acid is selected from Li + , Na + , K + , Ca 2+ , Mg 2+ or Al 3+ and the Lewis base is selected from anions of a polyprotic Bronsted acid.
• the total concentration of these builders is at least 0.4 mol/kg, preferably at least 0.5 mol/kg, particularly preferably at least 0.6 mol/kg. Normally, higher concentrations are not necessary or do not provide any further improvement in wettability for the subsequent process steps of cleaning and/or pretreatment to protect against corrosion.
• the total concentration of the builders is selected from salts of such Lewis acid-base pairs whose Lewis acid is selected from Li + , Na + , K + , Ca 2+ , Mg 2+ or Al 3+ and whose Lewis base is selected from anions of a polyprotic Brönsted acid, preferably does not exceed 2.0 mol/kg, particularly preferably 1.2 mol/kg, in the aqueous medium.
• Builders that are particularly suitable for conditioning are those in which the anions of the polyprotic Brönsted acid of the Lewis acid-base pair are selected from anions of sulfuric acid, phosphoric acid, diphosphoric acid, polyphosphoric acid, carbonic acid, particularly preferably from anions of phosphoric acid, diphosphoric acid, Polyphosphoric acid, carbonic acid, very particularly preferably from anions of carbonic acid.
• Suitable builders can also be provided based on polybasic organic acids and are then preferably selected from Lewis acid-base pairs whose Lewis bases are derived from anions of polybasic carboxylic acids, particularly preferably from di- and tricarboxylic acid anions, which in turn are preferably in the ⁇ -position have a hydroxyl group to a carboxyl group, and are very particularly preferably formed by anions of citric acid and/or tartaric acid.
• the proportion of such builders whose Lewis bases are formed from anions of organic acids, based on the total proportion of the builders, is preferably less than 50% by weight, particularly preferably less than 30% by weight, but preferably at least 0.05 mol/kg to give the conditioning agent an additional complexing effect, which is advantageous for further homogenization of the oxide covering of the (ZM) surfaces of the components.
• the cations Na + , K + and/or Mg 2+ have been found to be particularly suitable Lewis acids for the builders present in the aqueous agent for conditioning, which can be removed without residue by rinsing following process step ii), and are therefore preferred .
• the Lewis acids of the builders are particularly preferably selected from Na + and/or K + .
• the surfaces of (ZM) the components are sufficiently conditioned for subsequent cleaning and/or anti-corrosion pretreatment.
• the builders described are largely indifferent to the metal surfaces and their oxides and do not form any compact thin layers either through chemisorption, metallization or through conversion due to a coupled pickling and precipitation mechanism. In this respect, for the success of the conditioning advantageous and also desirable for economic reasons if the proportion of other components of the aqueous agent is reduced as much as possible.
• the proportion of water-soluble compounds of the elements Zr, Ti, Hf, Ce, Cr in the aqueous conditioning agent is less than 10 mg/kg, particularly preferably less than 5 mg/kg is less than 1 mg/kg based on the respective element.
• the proportion of water-soluble compounds of metal elements (Me), which have a more positive standard reduction potential than iron, preferably than zinc, in the aqueous conditioning agent is less than 10 mg/kg in each case. particularly preferably less than 5 mg/kg, particularly preferably less than 1 mg/kg, based on the respective element.
• the proportion of polymeric organic compounds in the aqueous conditioning agent is less than 1% by weight, particularly preferably less than 0.1% by weight, particularly preferably less than 0.05% by weight .-% is.
• an organic compound is polymeric if it has a molecular weight of more than 1,000 ⁇ .
• the proportion of dispersed particulate components in the aqueous conditioning agent is less than 1% by weight, particularly preferably less than 0.1% by weight, particularly preferably less than 0.05% by weight.
• the dispersed particulate component of the aqueous agent is the solids content that remains after drying the retentate of an ultrafiltration of a defined partial volume of the aqueous dispersion with a nominal cut-off limit of 10 kD (NMWC, Nominal Molecular Weight Cut Off), insofar as the ultrafiltration is carried out with the addition of deionized water ( ⁇ ⁇ 1 ⁇ Scm-1) is carried out until a conductivity below 10 ⁇ Scm -1 is measured in the filtrate.
• NMWC Nominal Molecular Weight Cut Off
• CM homogeneously conditioned
• the surfactants in both method steps i) and ii) are selected identically, since in this way the components are transferred directly, so to speak wet-on-wet, from the pre-cleaning to the conditioning without a rinsing step can become.
• the pH of the aqueous conditioning agent is preferably above 6.5, and the agent is particularly preferably made alkaline, but with the proviso that heavy pickling of the metallic materials of the component, in particular the surfaces of (ZM), is ideally avoided becomes.
• the method should be suitable for the treatment of components composed of various metallic production materials, in particular those composed of steel and/or aluminum in addition to hot-dip galvanized (ZM) steel, for example automobile bodies. Accordingly, it is preferred according to the invention if the pH of the aqueous conditioning agent is not greater than 10.5, particularly preferably not greater than 9.5, particularly preferably not greater than 8.5, but is preferably at least 7.5.
• the total alkalinity in points of the aqueous conditioning composition is preferably less than 30 points, more preferably less than 25 points, but preferably at least 10, more preferably at least 15 points.
• the total alkalinity in points of the aqueous conditioning composition is preferably less than 30 points, more preferably less than 25 points, but preferably at least 10, more preferably at least 15 points.
• Buffer effect produced by the builder or builders contained in the aqueous agent which has proven to be advantageous for the conditioning of the hot-dip galvanized (ZM) surfaces.
• the free alkalinity should not exceed such values that the result is excessive pickling attack, which can prove disadvantageous, particularly when applied as a thin liquid film, and may require a further rinsing step, for example.
• aqueous conditioning agents whose free alkalinity is below 10.0, particularly preferably below 8.0, very particularly preferably below 7.0.
• Total or free alkalinity is determined by titrating 2 grams of the aqueous composition diluted to 50 ml with 0.1N hydrochloric acid to pH 3.6. The consumption of acid solution in ml gives the total alkalinity score.
• the way in which the aqueous agent is applied can also prove to be selective for successful conditioning in a series treatment of components, since it can be observed that the wettability of the surfaces of (ZM) after going through process step ii) with the treated Total surface decreases progressively, insofar as the components of the series are treated with the same liquid volume of the conditioning agent, i.e. regularly when the treated surface per volume of the agent increases continuously with the number of treated components, as is the case, for example, in an immersion application or a spray application with closed circulation of the agent drained from the components is usually the case.
• the surfaces of the galvanized (ZM) steel of the components are therefore brought into contact in method step ii) by dispensing the aqueous agent from a supply in such a way that per square meter of area to be cleaned and/or protected against corrosion components of the series to be protected, in particular per square meter of the surfaces of galvanized (ZM) steel to be brought into contact with the components of the series to be cleaned and/or protected against corrosion, no more than 1.00 liter, preferably no more than 0.50 liters, more preferably not more than 0.20 liters of the aqueous agent is dispensed.
• the surface of the series components to be cleaned and/or protected against corrosion is the surface of that polyhedron with 12 surfaces, preferably with 6 faces, and particularly preferably that cuboid that completely encloses the component and has the smallest surface area, with each face of the polyhedron touching the component at at least one point.
• the component is an automobile body
• its area in connection with the areal output of the aqueous conditioning agent is preferably that of the cuboid with the smallest surface area that completely encompasses the automobile body, with each surface of the cuboid touching the automobile body at at least one point.
• the amount of the aqueous agent that is dispensed should be distributed as effectively as possible over the surfaces of (ZM) without this not contributing to the wetting and, for example, ensuring that the volume of liquid does not flow off the surfaces of the component again immediately after application .
• the aqueous agent for bringing into contact is dispensed in method step ii) in such a way that at least the surfaces of the galvanized (ZM) steel are covered by a liquid film of the aqueous agent, with the surfaces of the galvanized (ZM ) Steel results in a surface-related volume requirement of preferably not more than 0.20 liters, particularly preferably not more than 0.10 liters, very particularly preferably not more than 0.07 liters and particularly preferably not more than 0.05 liters.
• the volume requirement here does not refer to the surface of the component approximated via polyhedrons, as is the case with the volume output, but to the respective actual geometric surface, with the volume requirement being able to be determined by differential weighing after the liquid film has been blown off.
• the aqueous agent is released as a spray ( Spray), as a spray mist or as a liquid film, particularly preferably as a drizzle (spray) and/or spray mist, particularly preferably as a spray mist.
• the agent is brought into contact with the surfaces of the component as a drizzle (spray) and/or spray mist using methods for spraying and misting that are established in the prior art and can be locally limited using a spray lance and/or partially enclosing the component using a spray ring, in which a large number of atomizer nozzles can be installed.
• the spraying devices to be used for dispensing a mist (spray) and/or mist are, for example, pressure atomizers, rotary atomizers or two-component atomizers.
• a liquid film can be applied to the component using rollers, cloths, brushes, brushes or similar tools for applying liquids in the direct application process.
• aqueous agent for conditioning is particularly efficient by setting a drizzle that is targeted to the surfaces to be wetted, and/or by providing a spray mist, through which the component is transported together with the conveyor frame and which is realized at a given volume flow over such a transport route that the surfaces of the component to be wetted are just exposed to a closed film of liquid.
• a spray mist through which the component is transported together with the conveyor frame and which is realized at a given volume flow over such a transport route that the surfaces of the component to be wetted are just exposed to a closed film of liquid.
• the agent dispensed as a drizzle (spray) and/or the spray mist in method step ii) has an average droplet size of less than 100 ⁇ m, particularly preferably less than 60 ⁇ m, particularly preferably less than 40 ⁇ m. With average droplet sizes below 40 ⁇ m, the agent is so strongly atomized that the border area to the aerosols is exceeded and a spray mist is present. If the agent is further atomized and the mean droplet size is reduced, the droplets become increasingly suspended and do not follow gravity.
• the agent dispensed for conditioning in process step ii) has an average droplet size of not less than 5 ⁇ m, particularly preferably not less than 10 ⁇ m.
• the formation of a closed liquid film on the surfaces of the components is also advantageous for the formation of a closed liquid film on the surfaces of the components to be brought into contact if the drizzle (spray) and/or spray mist of the conditioning agent is emitted in such a way that the average speed of the liquid droplets, which have the average droplet size , less than 5 m/s, preferably less than 2 m/s and particularly preferably less than 1 m/s.
• the average droplet size and average speed of the droplets of a drizzle (spray) or mist is determined at the location of the geometric center of gravity of that polyhedron enclosing the component, which is also used to determine the amount of agent dispensed per area of the component, as described above.
• the determination can be made by means of light scattering and phase Doppler anemometry.
• method step ii) is carried out in such a way that the part of the aqueous agent dispensed for contacting that is not brought into contact with the component and, for example, as an excess spray sinks to the bottom and there is collected, or which does not remain on the same until it is brought into contact with an aqueous solution in process step iii), and for example runs off the component and remains in the spray chamber, is discarded.
• a portion of the conditioning agent is considered "discarded" when it is no longer intended to be contacted and is removed, for example, from the spray chamber.
• Process step iii) which follows the treatment stage for conditioning, concludes the process by completing or completing the cleaning and/or anti-corrosion pretreatment.
• Cleaning in the sense of this process step is a wet-chemical treatment with a cleaning solution, as a result of which the metallic surfaces of the component, but at least the surfaces of the hot-dip galvanized (ZM) steel substrates, are freed from adhering organic impurities, so that a carbon layer of less than 0.10 g, preferably less than 0.05 g of carbon per square meter of the (ZM) surface of the components, preferably per square meter of all metallic surfaces of the component.
• ZM hot-dip galvanized
• cleaning within the meaning of process step iii) also includes treatment with cleaning solutions which, as a result of their pickling reactions, bring about a transformation of the oxide layers on the metallic surfaces.
• cleaning within the meaning of process step iii) if this results in a layer coverage of more than 1 mg/m 2 with metallic or semi-metallic foreign elements based on the respective elements.
• the person skilled in the art speaks of a conversion layer formation which is attributable to the anti-corrosion pretreatment within the meaning of the present invention, which can be carried out either immediately after the conditioning or, if appropriate, after the aforementioned cleaning.
• passivations by means of inorganic barrier layers which can be either crystalline (phosphating) or amorphous (chromating, conversion treatment based on Zr/Ti), are particularly suitable as anti-corrosion pretreatment.
• the inorganic passivations also include alkaline passivation in the presence of iron ions and possibly other dissolved metal ions of the elements cobalt, nickel, manganese and molybdenum, as described, for example, in the published patent applications DE and DE.
• the present invention which ensures complete and permanent wettability of the (ZM) surfaces of components, is particularly advantageous for so-called thin-film passivations, since a lack of or incomplete wettability of the (ZM) surfaces often results in poorer corrosion protection with this type of passivation.
• those anti-corrosion pretreatments are preferred for process step iii), as a result of which a layer coverage of less than 200 mg/m 2 with metallic or semi-metallic foreign elements, based on the respective elements, results.
• a chromium-containing or preferably chromium-free conversion solution can be used as such a thin-layer passivation as an aqueous treatment solution for the anti-corrosion pretreatment in process step iii).
• Preferred conversion solutions with which the surfaces of the series components cleaned and conditioned according to the present invention can be treated are based on hexafluoroanions of the elements Zr, Ti, Hf and/or Si.
• the conversion solutions preferably additionally contain dissolved ions of the metals molybdenum, copper, bismuth and/or manganese.
• the components comprise the material hot-dip galvanized (ZM) steel.
• Hot-dip galvanizing (ZM) is a metallic coating that contains 1.5 to 8% by weight of the metals aluminum and magnesium, with the proportion of magnesium in the metallic coating being preferably at least 0.2% by weight.
• the method according to the invention is not limited to the application on hot-dip galvanized (ZM) steel, so that the common substrates provided by the steel industry, such as steel, in particular cold-rolled steel (CRS), as well as electrolytically galvanized (ZE) or hot-dip galvanized (Z), alloy-galvanized , in particular (ZF), (ZA), or steel coated with aluminum (AZ), (AS) can be considered as further components of the components.
• Light metals such as aluminum and magnesium and their alloys can also be treated in the process according to the invention together with the hot-dip galvanized (ZM) steel of the component and thereby cleaned and/or pretreated to protect against corrosion.
• the different materials are usually present in the component in the form of flat products that have been cut to size, shaped and joined together by welding, gluing and flanging.
• the components to be pretreated in series according to the present invention are preferably selected from automobile bodies or parts thereof, heat exchangers, profiles, pipes, tanks or tubs.
• inventively treated components can in a process step iii) subsequent process step with an organic top coat system, in particular a Dip coating, particularly preferably a cathodic electrocoating are supplied.
• an organic top coat system in particular a Dip coating, particularly preferably a cathodic electrocoating are supplied.

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• 2021
  • 2021-09-13 EP EP21196358.2A patent/EP4148163A1/fr not_active Withdrawn
• 2022
  • 2022-09-08 WO PCT/EP2022/075028 patent/WO2023036889A1/fr active Application Filing
  • 2022-09-08 KR KR1020247008192A patent/KR20240052772A/ko unknown
  • 2022-09-08 CA CA3231045A patent/CA3231045A1/fr active Pending
  • 2022-09-08 CN CN202280060928.1A patent/CN117957343A/zh active Pending

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