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
  • 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
  • C23C18/00—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating
  • C23C18/02—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by thermal decomposition
  • C23C18/12—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by thermal decomposition characterised by the deposition of inorganic material other than metallic material
  • C23C18/1229—Composition of the substrate
  • C23C18/1241—Metallic substrates
• • 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
  • C23C18/00—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating
  • C23C18/02—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by thermal decomposition
  • C23C18/12—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by thermal decomposition characterised by the deposition of inorganic material other than metallic material
  • C23C18/1204—Chemical coating by decomposition of either liquid compounds or solutions of the coating forming compounds, without leaving reaction products of surface material in the coating; Contact plating by thermal decomposition characterised by the deposition of inorganic material other than metallic material inorganic material, e.g. non-oxide and non-metallic such as sulfides, nitrides based compounds
  • C23C18/122—Inorganic polymers, e.g. silanes, polysilazanes, polysiloxanes
• • 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
  • C23C22/78—Pretreatment of the material to be coated
• • 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
  • C23C22/78—Pretreatment of the material to be coated
  • C23C22/80—Pretreatment of the material to be coated with solutions containing titanium or zirconium 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
  • C23C22/82—After-treatment
  • C23C22/83—Chemical after-treatment
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
  • C25D13/00—Electrophoretic coating characterised by the process
  • C25D13/20—Pretreatment
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
  • C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
  • C25D5/34—Pretreatment of metallic surfaces to be electroplated
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
  • C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
  • C25D5/34—Pretreatment of metallic surfaces to be electroplated
  • C25D5/36—Pretreatment of metallic surfaces to be electroplated of iron or steel
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
  • C25D5/00—Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
  • C25D5/34—Pretreatment of metallic surfaces to be electroplated
  • C25D5/42—Pretreatment of metallic surfaces to be electroplated of light metals
  • C25D5/44—Aluminium
• • 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
  • C23C2222/00—Aspects relating to chemical surface treatment of metallic material by reaction of the surface with a reactive medium
  • C23C2222/20—Use of solutions containing silanes
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]
  • Y10T428/31652—Of asbestos
  • Y10T428/31663—As siloxane, silicone or silane

Definitions

• the invention relates to a process for coating metallic surfaces with aqueous compositions, wherein in a pretreatment step a silane-based aqueous composition comprising at least one silane and / or a silicon-containing compound related thereto and optionally further components, without drying the coating e.g. is further treated at temperatures above 70 ° C by using at least one aqueous rinsing step after this pretreatment step and then an electrodeposition coating is carried out, wherein in the aqueous rinsing steps, at least in the last rinsing step, at least one surfactant is added.
• the first lacquer layer used is often an electrocoating with an electrodeposition coating (ETL), such as e.g. a cathodic electrodeposition paint (KTL) used.
• ETL electrodeposition coating
• KTL cathodic electrodeposition paint
• silanes / silanols in aqueous compositions for the preparation of siloxane / polysiloxane-rich corrosion-protective coatings is known in principle.
• silane / silanol / siloxane / polysiloxane is often referred to as silane in the following.
• These coatings have been proven, but the methods for coating with a predominantly silane in addition to solvent (s) containing aqueous composition sometimes difficult to apply. Not always, these coatings are formed with excellent properties.
• the corrosion protection and the paint adhesion of the formed siloxane or / and polysiloxane-rich coatings are often, but not always high and sometimes not sufficiently high for certain applications even with suitable application. It requires further methods using at least one silane, which have a high process safety and a high quality of the coatings produced herewith, in particular with regard to corrosion resistance and paint adhesion.
• silane-containing aqueous compositions moreover, a small or large amount of addition of at least one component selected from the group of organic monomers, oligomers and polymers has been proven.
• the type and amount of silane addition is in part of critical importance for success.
• the addition amounts of silane for this purpose are comparatively low - usually only up to 5 wt .-% of all solids contents - and then act as a "coupling agent", the adhesion-promoting effect in particular between metallic substrate and paint and optionally between pigment and organic paint constituents should prevail, but subordinate partially also a low cross-linking effect can occur.
• very little silane additives are added to thermosetting resin systems.
• these coatings are generally insensitive to water, since the condensation of silanes / silanols / Siloxanes / polysiloxanes is more advanced.
• the degree of drying associated with a condensation of the silanes / silanols / siloxanes / polysiloxanes and the rinse resistance of the siloxane / polysiloxane-containing coating will vary depending on the phase inventory, coating, and type of rinse.
• DE 102005015576 A1 describes the effects during pre-rinsing and / or rinsing before and after the silane pretreatment according to the invention mentioned therein.
• DE 20 17 327 A1 teaches a process in which on zinc-based metallic surfaces (a) the metal surfaces are treated with an aqueous conditioning liquid consisting of an aqueous solution of 1.5 to 10.0% by weight of sodium or potassium hydroxide together with at least 0.05% by weight each. % Iron ions and a masking agent for iron at a pH of at least 13 soaks, (b) the aqueous Rinsing conditioning fluid from the metal with water, (c) depositing a zinc phosphate conversion coating on the metal surface, and (d) electrophoretically depositing thereon a paint film.
• an aqueous conditioning liquid consisting of an aqueous solution of 1.5 to 10.0% by weight of sodium or potassium hydroxide together with at least 0.05% by weight each. % Iron ions and a masking agent for iron at a pH
• electrodeposition coating after a silane-based pretreatment has been a problem, especially in the automotive industry, to improve the quality of the electrodeposition coating, since in some situations it can be used on intricately shaped workpieces and constructions such as e.g. in housings and bodies is not sufficient to allow the same possible layer thicknesses of the electrodeposition coating outside and inside and thereby meet all other quality requirements for the paint.
• aqueous compositions whose coatings have the most environmentally friendly chemical composition and ensure high corrosion resistance, including in multi-metal applications, such as steel and zinc-rich metallic surfaces and optionally also aluminum-rich metallic surfaces be treated or pretreated in the same bath, are suitable. It was also the task of proposing a sequence of processes from pre-treatment to electrocoating, in which the lowest possible low-quality coatings of silane-based pretreatment and electrodeposition coating can be applied in particular to bodies in the automotive series production. Furthermore, the object was to propose a method with silane-containing aqueous compositions, which can be implemented in existing systems of the automotive industry in principle and is particularly suitable for coating car bodies in the automotive industry. Here, a coating quality of the pretreatment coating and the electrodeposition coating is to be achieved on body surfaces, as in the high-quality corrosion-protective coatings of zinc manganese nickel phosphating is achieved in order not to endanger the quality standards.
• complex fluoride in the silane-based pretreatment helps to minimize or avoid impairments of the attachment of silane to the metallic surface, so that the rinsing can have little or no effect.
• a combination of at least two complex fluorides in the silane-based pretreatment composition, in particular of fluorotitanic acid and of fluorozirconic acid or salts thereof, also makes possible an extraordinary increase in the quality of the coatings.
• an aqueous silane-based pretreatment composition in a coating process according to at least one of claims 1 to 22 for metallic substrates for improving the encapsulation of an electrodeposition coating, in which an aqueous silane-based composition according to at least one of claims 1 to 16 is contacted with a metallic substrate in which the coating newly applied with this composition is rinsed at least once with water, rinsing at least once with water containing surfactant, after rinsing with water an electrodeposition paint Coating is applied, wherein the freshly applied with this composition coating is not dried until this rinsing, so that the at least one condensable compound a) until rinsing the pretreatment coating with water or / and until coating m it is not strongly condensed with an electrodeposition paint and an aqueous treatment containing a water-dissolved iron compound is carried out prior to treatment with an aqueous silane-based pretreatment composition.
• an aqueous silane-based pretreatment composition in a coating process according to at least one of claims 2 to 22 for metallic substrates to improve the application of an electrodeposition coating
• the substrates before the aqueous silane-based pretreatment at least once with an aqueous iron composition in which an aqueous silane-based composition according to any one of claims 2 to 16 is brought into contact with a metallic substrate, wherein the freshly applied with this composition coating at least once with water is rinsed, wherein optionally rinsed at least once with water containing a surfactant in which after rinsing with water, an electrodeposition coating is applied
• the pretreatment composition freshly applied Vorbehandlu ngs coating until application of a subsequent electrodeposition coating is not dried through, so that the at least one condensable compound a) is not strongly condensed until application of the subsequent electrodeposition coating and wherein prior to treatment with an aqueous silane-based pretreatment composition aqueous treatment with a content of water-dissolved iron
• a second conversion layer or / and a coating as a result of application of a rinsing solution can also be used in the middle of this process sequence.
• the second conversion layer or coating as a result of application of a rinsing solution is preferably an aqueous composition based on at least one silane / silanol / siloxane / polysiloxane, of at least one titanium, hafnium, zirconium, aluminum or / and boron-containing compound such as eg at least one complex fluoride, of at least one organic compound selected from monomers, oligomers, polymers, copolymers and block copolymers or / and of at least one Phosphorus and oxygen containing compound.
• the concentration of the aqueous composition for the second conversion layer or the rinsing solution is generally lower than a comparable aqueous composition for the first conversion layer, namely the silane-based pretreatment coating according to the invention.
• the wet film of the silane-based pretreatment according to the invention can be rinsed without prior stronger drying of the wet film with water or / and with an aqueous composition which optionally contains surfactant.
• a subsequent coating can then be applied to this wet film in the not yet dried state.
• the rinsing of the wet film after the silane pretreatment is preferably carried out immediately after coating with the silane-containing aqueous composition, especially within one or two Minutes after coating with the silane pretreatment according to the invention, more preferably within 30 seconds or even within 10 seconds after this coating.
• the electrodeposition paint is applied immediately after rinsing, especially within two or three minutes after rinsing the silane-based pretreatment coating, more preferably within 60 seconds or even within 20 seconds.
• the paint may in this case be in particular an electrodeposition paint or a water-containing wet paint.
• it can often happen, especially in industrial production, that the time from the end of rinsing with water until application of the electrodeposition paint is 1 to 120 minutes, but preferably only 2 to 60 or 3 to 40 or 4 to 20 minutes.
• the at least one, still condensable silane / silanol / siloxane is even more chemically reactive and can react more intensively with the subsequently applied electrodeposition paint than an already thoroughly dried and thermally influenced strongly condensed silane / silanol / siloxane / polysiloxane. It is believed that even after a latency period of up to several hours, as long as no temperatures above 40 ° C. are used, the silane-based pretreatment coating dries out.
• silane is used here for silanes, silanols, siloxanes, polysiloxanes and their reaction products or derivatives, which are often also "silane” mixtures.
• condensation in the context of this application refers to all forms of crosslinking, further crosslinking and further chemical reactions of the silanes / silanols / siloxanes / polysiloxanes. Usually, this is based on an addition as silane, wherein the added at least one silane is often at least partially hydrolyzed, where it usually forms the first contact with water or moisture at least one silanol, formed from the at least one siloxane and later optionally also at least one polysiloxane will or can be.
• the term "coating” refers to the coating formed with the aqueous composition, including the wet film, the dried film, the throughdried film, the elevated-temperature-dried film and the optionally thermally and / or irradiated further crosslinked film.
• the aqueous silane-based pretreatment composition is an aqueous solution, an aqueous dispersion or / and an emulsion.
• its pH is greater than 1.5 and less than 9, more preferably in the range of 2 to 7, most preferably in the range of 2.5 to 6.5, in particular in the range of 3 to 6.
• a pH Value of eg 2.5 can significantly reduce the deposition of titanium or zirconium compounds, e.g. occur from the complex fluoride, which can be affected by slight reduction of the layer properties.
• the complex fluoride contained in the bath may become unstable and precipitation may occur.
• the aqueous silane-based pretreatment composition is particularly preferably at least one silane or / and at least one corresponding compound having at least one amino group, at least one urea group or / and at least one Ureido group (imino) added, since the coatings produced herewith often show a higher paint adhesion and / or a higher affinity to the subsequent electrodeposition coating layer.
• care must be taken that the condensation may be very rapid at pH values below 2.
• the proportion of aminosilanes, ureidosilanes or / and silanes having at least one urea group or / and corresponding silanols, siloxanes and polysiloxanes can be increased in the sum of all types of compounds selected from silanes, silanols, siloxanes and polysiloxanes, more preferably above 20 , over 30 or over 40 wt .-% are calculated as the corresponding silanols, most preferably above 50, above 60, above 70 or above 80 wt .-% are and optionally even up to 90, up to 95 or up to 100 Wt .-% amount.
• the aqueous silane-based pretreatment composition has a silane / silanol / siloxane / polysiloxane content a) in the range of 0.005 to 80 g / L, calculated on the basis of the corresponding silanols.
• This content is particularly preferably in the range from 0.01 to 30 g / l, very particularly preferably in the range from 0.02 to 12 g / l, to 8 g / l or to 5 g / l, in particular in the range from 0, 05 to 3 g / L or in the range of 0.08 to 2 g / L or to 1 g / L.
• These content ranges relate in particular to bath compositions.
• a concentrate is used to prepare a corresponding bath composition, in particular by dilution with water and optionally by adding at least one further substance, it is advisable to separate, for example, a concentrate A containing silane / silanol / siloxane / polysiloxane a) to keep a concentrate B containing all or almost all other constituents and to bring these components together in the bathroom.
• a concentrate A containing silane / silanol / siloxane / polysiloxane a
• a concentrate B containing all or almost all other constituents and to bring these components together in the bathroom.
• at least one silane, silanol, siloxane and / or polysiloxane are also partly or wholly in the solid state, are added in the solid state and / or are added as dispersion or solution.
• the concentration ranges of the bath may have different salary ranges depending on the application.
• the aqueous silane-based pretreatment composition particularly preferably contains at least one silane, silanol, siloxane or / and polysiloxane a) each having at least one group selected from acrylate groups, amino groups, succinic anhydride groups, carboxyl groups, epoxy groups, glycidoxy groups, hydroxy groups, ureido groups (Imino), isocyanato groups, methacrylate groups and / or urea groups per molecule, wherein also aminoalkyl groups, alkylaminoalkyl groups and / or alkylamino groups can occur.
• This composition particularly preferably contains at least one silane, silanol, siloxane or / and polysiloxane a) having at least two amino groups, at least three amino groups, at least four amino groups, at least five amino groups or / and at least six amino groups per molecule ,
• the silanes, silanols, siloxanes or / and polysiloxanes in the aqueous silane-based pretreatment composition, or at least their compounds initially added to the aqueous composition, or at least a portion of them are preferably water-soluble.
• the silanes are considered to be water-soluble if they have a solubility in water of at least 0.05 g / l, preferably of at least 0.1 g / l, at room temperature in the silane / silanol / siloxane / polysiloxane-containing composition. more preferably at least 0.2 g / L or at least 0.3 g / L.
• At least one silane / silanol / siloxane / polysiloxane is selected from fluorine-free silanes and the corresponding silanols / siloxanes / polysiloxanes each of at least one acyloxysilane, an alkoxysilane, a silane having at least one amino group such as an aminoalkylsilane, a silane having at least one succinic group and / or succinic anhydride group, a bis-silyl silane, a silane having at least one epoxy group such as a glycidoxysilane, a (meth) acrylato-silane, a multi-silyl-silane, a ureidosilane, a vinyl silane or / and at least one silanol
• the at least one silane or the corresponding silanol / siloxane / polysiloxane has in each case at least one amino group, urea group or / and ureido group.
• At least one silane and / or at least one corresponding silanol / siloxane / polysiloxane is contained or / and initially added selected from the group of or based on (3,4-epoxyalkyl) trialkoxysilane, (3,4-Epoxycycloalkyl) alkyltrialkoxysilane, 3-acryloxyalkyltrialkoxisilane, 3-Glycidoxyalkyltrialkoxysilan, 3-methacryloxyalkyltrialkoxysilane, 3- (trialkoxysilyl) alkylbernsteinklaklasilan, 4-amino-dialkylalkyltrialkoxysilan, 4-amino-dialkylalkylalkyldialkoxysilan, Aminoalkylaminoalkyltrialkoxysilan, Aminoalkylaminoalkylalkyldialkoxysilan, aminoalkyl, amine bis (trial
• aqueous composition at least one silane / silanol / siloxane / polysiloxane containing a fluorine-containing group.
• silane compound (s) the hydrophilicity / hydrophobicity can be set purposefully.
• At least one at least partially hydrolyzed, at least partially condensed silane / silanol / siloxane / polysiloxane is added to the aqueous silane-based pretreatment composition.
• at least one pre-hydrolyzed, pre-condensed silane / silanol / siloxane / polysiloxane may optionally be added in each case. Such an additive is particularly preferred.
• At least one silane / silanol / siloxane / polysiloxane at least substantially or / and completely hydrolyzed and / or at least substantially or / and completely condensed may be added to the aqueous silane-based pretreatment composition.
• an unhydrolyzed silane binds poorer to the metallic surface than an at least partially hydrolyzed silane / silanol.
• a largely hydrolyzed and not or only slightly condensed silane / silanol / siloxane binds much better in many embodiments of the metallic surface than an at least partially hydrolyzed and largely condensed silane / silanol / siloxane / polysiloxane.
• a completely hydrolyzed and largely condensed silanol / siloxane / polysiloxane shows in many embodiments only a slight tendency to be chemically bound to the metallic surface.
• At least one silane that is multi-branched or / and has from three to twelve amino groups per molecule may be added to the aqueous silane-based pretreatment composition.
• the silane-based aqueous pretreatment composition may additionally or alternatively and / or silane (s) / silanol (s) be added with at least one siloxane or / and polysiloxane containing no or only a minor amount - e.g. less than 20 or less than 40% by weight of the sum of silane / silanol / siloxane / polysiloxane - of silanes / silanols.
• the siloxane or polysiloxane is preferably short-chain and is preferably applied by rollcoater treatment. If necessary, this will then have an effect on the coating due to greater hydrophobicity and higher blank corrosion protection.
• the aqueous silane-based pretreatment composition comprises at least two or even at least three compounds of titanium, hafnium and zirconium. These compounds may differ in their cations and / or in their anions.
• the aqueous composition, in particular the bath composition preferably has a content of at least one complex fluoride b), more preferably at least two complex fluorides selected from complex fluorides of titanium, hafnium and zirconium. Preferably, their difference is not only in the nature of the complex.
• the aqueous silane-based Pretreatment composition in particular the bath composition, a content of compounds b) selected from compounds of titanium, hafnium and zirconium in the range of 0.01 to 50 g / L calculated as the sum of the corresponding metals.
• This content is particularly preferably in the range from 0.05 to 30 g / l, very particularly preferably in the range from 0.08 to 15 g / l, in particular in the range from 0.1 to 5 g / l.
• the aqueous silane-based pretreatment composition contains at least one complex fluoride, wherein the content of complex fluoride (s) is in particular in the range of 0.01 to 100 g / L calculated as the sum of the corresponding metal complex fluorides as MeF 6 .
• the content is preferably in the range from 0.03 to 70 g / L, particularly preferably in the range from 0.06 to 40 g / L, very particularly preferably in the range from 1 to 10 g / L.
• the complex fluoride can be present in particular as MeF 4 or / and as MeF 6 , but also in other stages or intermediates.
• at least one titanium and at least one zirconium complex fluoride are present.
• At least one MeF 4 and at least one MeF 6 complex in the composition at the same time, in particular at the same time a TiF 6 and a ZrF 4 complex. It may be advantageous to adjust these complex fluoride ratios already in the concentrate and to take over in this way in the bath.
• the individual complex fluorides do not interfere negatively when combined, but exhibit an unexpected positive enhancement effect.
• These complex fluoride-based additives appear to act in a similar or similar manner. If a combination of complex fluorides based on titanium and zirconium and not just a complex fluoride based only on titanium or only one based on zirconium is used, surprisingly, results are always noticeably better than with a single one of these additives. On the Surface deposits a complex fluoride based on titanium or zirconium probably as oxide or / and hydroxide.
• a different type of titanium, hafnium and zirconium compound may also be added, for example, at least one hydroxycarbonate and / or at least one other water-soluble or slightly water-soluble compound, e.g. at least one nitrate and / or at least one carboxylate.
• cations or corresponding compounds c) selected from the group of aluminum, barium, magnesium, calcium, indium, yttrium, lanthanum, cerium, vanadium, niobium, tantalum, molybdenum, tungsten, Lead, manganese, iron, cobalt, nickel, copper, silver, bismuth, tin and zinc, more preferably from the group of aluminum, magnesium, calcium, yttrium, lanthanum, cerium, vanadium, molybdenum, tungsten, manganese, iron, cobalt, Copper, bismuth, tin and zinc, if trace levels of less than 0.005 g / L in the bath composition except for copper and silver are excluded, calculated as metal.
• cations and / or corresponding compounds c) in this case only types of cations or corresponding compounds selected from the group of magnesium, calcium, yttrium, lanthanum, cerium, manganese, iron, cobalt, copper, tin and zinc or selected from the group of calcium, yttrium, manganese, iron, cobalt, copper, tin and zinc, if from Trace levels of less than 0.005 g / L in the bath composition except for copper and silver, calculated as metal.
• Individual ones of these cations or compounds may also be preferred here in order to increase the conductivity of the respective coating or / and an interface in order to improve a connection to a coating or / and to produce similar cations in the aqueous silane-based pretreatment composition, to be used in at least one water rinse and / or in the electrodeposition paint.
• the aqueous silane-based pretreatment composition in particular the bath composition, has a content of cations and / or corresponding compounds c) in the range from 0.01 to 20 g / L, calculated as the sum of the metals. It is particularly preferably in the range from 0.03 to 15 g / L, very particularly preferably in the range from 0.06 to 10 g / L, in particular in the range from 0.1 to 6 g / L.
• the content of each individual type of cations or compounds c) in the aqueous silane-based pretreatment composition is in the range from 0.005 to 0.500 g / L, from 0.008 to 0.100 g / L or from 0.012 to 0.050 g / L is calculated as the metal, except for grades of cations of copper and silver, which may have a significant influence even in smaller quantities such as 0.001 to 0.030 g / L, where 1 ppm corresponds to 0.001 g / L.
• the preferred levels in the aqueous silane-based pretreatment composition are of varying magnitude.
• the aqueous silane-based pretreatment composition contains at least one kind of cations selected from cations of cerium, chromium, iron, calcium, cobalt, copper, magnesium, manganese, molybdenum, nickel, niobium, tantalum, yttrium, zinc, tin and other lanthanides or / and at least one corresponding compound.
• at least two, at least three, or at least four different types of cations are added, or at least three, at least four, or at least five different types of cations are found in the aqueous silane-based pretreatment composition.
• Cations of aluminum, iron, cobalt, copper, manganese, tin and zinc 2.
• Cations of cerium, iron, calcium, magnesium, manganese are particularly preferred in this case combinations of cations or their compounds selected from the group 1.) , Yttrium, zinc and tin, 3.) of cations of copper, manganese and zinc or 4.) of cations of aluminum, iron, calcium, copper, magnesium, manganese and zinc.
• not all cations contained in the aqueous composition have not only been dissolved out of the metallic surface by the aqueous composition, but also at least partially or even substantially added to the aqueous composition. Therefore, a freshly prepared bath of certain cations or compounds may be free, which are released only from reactions with metallic materials or from reactions in the bath or arise.
• manganese ions or of at least one manganese compound has surprisingly been found to be particularly advantageous. Although apparently no or almost no manganese compound is deposited on the metallic surface, this additive apparently promotes the Deposition of silane / silanol / siloxane / polysiloxane and thus significantly improves the properties of the coating.
• An addition of magnesium ions or at least one magnesium compound has unexpectedly been found to be advantageous, since this addition promotes the deposition of titanium and / or zirconium compounds, presumably as oxide and / or hydroxide, on the metallic surface and thus the properties of the coating clearly improved. A combined addition of magnesium and manganese leads in part to even further improved coatings.
• the aqueous silane-based pretreatment composition contains at least one kind of cation or / and corresponding compounds selected from alkaline earth metal ions in the range of 0.01 to 50 g / L calculated as corresponding compounds, more preferably in the range of 0.03 to 35 g / L, most preferably in the range of 0.06 to 20 g / L, in particular in the range of 0.1 to 8 g / L or to 1.5 g / L.
• the alkaline earth metal ions or corresponding compounds may help to enhance the deposition of compounds based on titanium or / and zirconium, which is often advantageous in particular for increasing the corrosion resistance.
• the aqueous silane-based pretreatment composition contains at least one kind of cation selected from cations of aluminum, iron, cobalt, magnesium, manganese, nickel, yttrium, tin, zinc and lanthanides or / and at least one corresponding compound c) , in particular in the range of 0.01 to 20 g / L, calculated as the sum of the metals.
• the composition contains a content of at least one organic compound d) selected from monomers, oligomers, polymers, copolymers and block copolymers, in particular at least one compound based on acrylic, epoxy or / and urethane.
• at least one organic compound having at least one silyl group can also be used.
• the aqueous silane-based pretreatment composition contains a content of at least one organic compound d) selected from monomers, oligomers, polymers, copolymers and block copolymers in the range of 0.01 to 200 g / L calculated as a solid additive.
• the content is particularly preferably in the range from 0.03 to 120 g / L, very particularly preferably in the range from 0.06 to 60 g / L, in particular in the range from 0.1 to 20 g / L.
• organic compounds may help in some embodiments to even out the formation of the coating.
• These compounds may contribute to the formation of a more compact, denser, more chemically resistant or / and more water resistant coating compared to silane / silanol / siloxane / polysiloxane-based coatings, etc., without these compounds.
• the hydrophilicity / hydrophobicity can be set purposefully.
• a highly hydrophobic coating is problematic in some applications because of the required attachment of particular water-based paints.
• an additive of at least one organic compound may combine with compounds prove particularly advantageous with a certain functionality such as compounds based on amines / diamines / polyamines / urea / imines / diimines / polyimines or their derivatives, compounds based on particular capped isocyanates / isocyanurates / melamine compounds, compounds with carboxyl or / and hydroxyl groups such as carboxylates, long-chain sugar-like compounds such as (synthetic) starch, cellulose, saccharides, long-chain alcohols or / and derivatives thereof.
• long-chain alcohols in particular those having 4 to 20 C atoms are added, such as butanediol, butyl glycol, butyl diglycol, ethylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol propyl ether, ethylene glycol hexyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol butyl ether, diethylene glycol hexyl ether or a propylene glycol ether such as propylene glycol monomethyl ether , Dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monobutyl ether, propylene glycol monopropyl ether, dipropylene glycol monopropyl ether, tripropylene glycol monopropyl ether,
• the weight-based ratio of compounds based on silane / silanol / siloxane / polysiloxane calculated on the basis of the corresponding silanols to compounds based on organic polymers calculated as a solids addition in the composition is preferably in the range from 1: 0.05 to 1: 30, especially preferably in the range of 1: 0.1 to 1: 2, most preferably in the range of 1: 0.2 to 1: 20. In many embodiments, this ratio is in the range of 1: 0.25 to 1: 12, im Range of 1: 0.3 to 1: 8 or in the range of 1: 0.35 to 1: 5.
• the aqueous silane-based pretreatment composition contains a content of silicon-free compounds having at least one amino, urea or / and ureido group, in particular compounds of amine / diamine / polyamine / urea / imine / diimine / polyimine and their Derivatives, preferably in the range of 0.01 to 30 g / L calculated as the sum of the corresponding compounds.
• the content is particularly preferably in the range from 0.03 to 22 g / L, very particularly preferably in the range from 0.06 to 15 g / L, in particular in the range from 0.1 to 10 g / L.
• An addition to, for example, aminoguanidine significantly improves the properties of the coatings according to the invention.
• the aqueous silane-based pretreatment composition contains a content of anions of nitrite and compounds having a nitro group, preferably in the range of 0.01 to 10 g / L calculated as the sum of the corresponding compounds.
• the content is particularly preferably in the range from 0.02 to 7.5 g / l, very particularly preferably in the range from 0.03 to 5 g / l, in particular in the range from 0.05 to 1 g / l.
• This substance is preferably added as nitrous acid HNO 2 , as an alkali metal nitrite, as ammonium nitrite, as nitroguanidine or / and as paranitrotoluenesulphonic acid, in particular as sodium nitrite or / and nitroguanidine.
• nitroguanidine an addition, in particular of nitroguanidine, to the aqueous silane-based pretreatment composition makes the appearance of the coatings according to the invention very uniform and noticeably increases the coating quality. This has a very positive effect especially on "sensitive" metallic surfaces such as sandblasted iron or steel surfaces. Addition of nitroguanidine markedly improves the properties of the coatings according to the invention.
• the aqueous silane-based pretreatment composition contains peroxide-based compounds such as hydrogen peroxide and / or at least one organic peroxide, preferably in the range of 0.005 to 5 g / L calculated as H 2 O 2 .
• the content is particularly preferably in the range from 0.006 to 3 g / l, very particularly preferably in the range from 0.008 to 2 g / l, in particular in the range from 0.01 to 1 g / l.
• the bath often yields a titanium-peroxo complex which dyes the solution or dispersion in orange. However, this color is typically not in the coating, as this complex does not appear to be incorporated as such into the coating. Therefore, the color of the bath can be used to estimate the titanium content or peroxide content.
• the substance is added as hydrogen peroxide.
• the aqueous silane-based pretreatment composition contains a content of phosphorus-containing compounds, preferably in the range of 0.01 to 20 g / L calculated as the sum of the phosphorus-containing compounds.
• these compounds contain phosphorus and oxygen, especially as oxyanions and as corresponding compounds.
• the content is particularly preferably in the range from 0.05 to 18 g / L, very particularly preferably in the range from 0.1 to 15 g / L, in particular in the range from 0.2 to 12 g / L.
• at least one orthophosphate an oligomeric and / or polymeric phosphate and / or a phosphonate is added.
• the at least one orthophosphate and / or salts thereof and / or their esters may be, for example, in each case at least one alkali phosphate, iron, manganese or / and zinc-containing orthophosphate and / or at least one of their salts and / or esters.
• at least one metaphosphate, polyphosphate, pyrophosphate, triphosphate or / and their salts and / or their esters may also be added in each case.
• the phosphonate for example, at least one phosphonic acid such as at least one alkyl diphosphonic acid and / or its salts and / or its esters can be added in each case.
• the phosphorus-containing compounds of this substance group are not surfactants.
• the aqueous silane-based pretreatment composition contains at least one kind of anions selected from carboxylates such as acetate, butyrate, citrate, formate, fumarate, glycolate, hydroxyacetate, lactate, laurate, maleate, malonate, oxalate, propionate, stearate, Tartrate or / and at least one corresponding, non-or / and only partially dissociated compound.
• carboxylates such as acetate, butyrate, citrate, formate, fumarate, glycolate, hydroxyacetate, lactate, laurate, maleate, malonate, oxalate, propionate, stearate, Tartrate or / and at least one corresponding, non-or / and only partially dissociated compound.
• the aqueous silane-based pretreatment composition contains a content of carboxylate anions and / or carboxylate compounds in the range of 0.01 to 30 g / L calculated as the sum of the corresponding compounds.
• the content is particularly preferably in the range from 0.05 to 15 g / L, very particularly preferably in the range from 0.1 to 8 g / L, in particular in the range from 0.3 to 3 g / L.
• At least one citrate, lactate, oxalate or / and tartrate can particularly preferably be added as carboxylate in each case.
• the addition of at least one carboxylate can help to complex a cation and to keep it more easily in solution, whereby a higher bath stability and controllability of the bath can be achieved.
• it has been found that the binding of a silane to the metallic surface can be partially facilitated and improved by a carboxylate content.
• the aqueous silane-based pretreatment composition also contains a level of nitrate.
• a content of nitrate in the range of 0.01 to 20 g / L calculated as the sum of the corresponding compounds.
• the content is particularly preferably in the range from 0.03 to 12 g / l, very particularly preferably in the range from 0.06 to 8 g / l, in particular in the range from 0.1 to 5 g / l.
• Nitrate can help to even out the formation of the coating, especially on steel. If necessary, nitrite can convert, usually only partially, into nitrate.
• Nitrate may in particular be added as alkali metal nitrate, ammonium nitrate, heavy metal nitrate, as nitric acid and / or corresponding organic compound.
• the nitrate can significantly reduce the tendency to rust, especially on surfaces of steel and iron.
• the nitrate may contribute to the formation of a defect-free coating or / and an exceptionally level coating which may be free of optically detectable marks.
• the aqueous silane-based pretreatment composition preferably contains at least one kind of cation selected from alkali metal ions, ammonium ions and corresponding compounds, in particular potassium or / and sodium ions or at least one corresponding compound.
• the aqueous silane-based pretreatment composition contains a free fluoride content in the range of 0.001 to 3 g / L, calculated as F - .
• the content is preferably in the range from 0.01 to 1 g / l, particularly preferably in the range from 0.02 to 0.5 g / l, very particularly preferably in the range up to 0.1 g / l. It has been found that in many embodiments it is advantageous to have a low level of free fluoride in the bath because the bath can then be stabilized in many embodiments. Excessive free fluoride content can sometimes negatively affect the rate of deposition of cations.
• non-dissociated or / and not complex-bound fluoride in particular in the range of 0.001 to 0.3 g / L occur.
• Such an additive is preferably added in the form of hydrofluoric acid and / or its salts.
• the aqueous silane-based pretreatment composition contains at least one fluoride-containing compound and / or fluoride anions, calculated as F - and without the inclusion of complex fluorides, in particular at least one fluoride of an alkali fluoride (s), ammonium fluoride and / or Hydrofluoric acid, more preferably in the range of 0.001 to 12 g / L, most preferably in the range of 0.005 to 8 g / L, in particular in the range of 0.01 to 3 g / L.
• s alkali fluoride
• Hydrofluoric acid more preferably in the range of 0.001 to 12 g / L, most preferably in the range of 0.005 to 8 g / L, in particular in the range of 0.01 to 3 g / L.
• the fluoride ions or corresponding compounds can help to control the deposition of the metal ions on the metallic surface, so that, for example, the deposition of the at least one zirconium compound can be enhanced or reduced if necessary.
• the aqueous silane-based pretreatment composition may contain at least one compound selected from alkoxides, carbonates, chelates, surfactants and additives, such as e.g. Biocides and / or defoamers.
• a catalyst for the hydrolysis of a silane e.g. Acetic acid are added.
• the blunting of the pH of the bath can be carried out, for example, with ammonia / ammonium hydroxide, an alkali hydroxide or / and an amine-based compound such as e.g. Monoethanolamine occur while the pH of the bath is preferably lowered with acetic acid, hydroxyacetic acid and / or nitric acid.
• Such contents are among the pH-affecting substances.
• the abovementioned contents or additives generally have a beneficial effect in the aqueous silane-based pretreatment compositions according to the invention in that they further improve the good properties of the inventive aqueous base composition comprising components a), b) and solvent (s).
• These additives usually work in the same way if only one titanium or only one zirconium compound or a combination of these is used.
• the combination of at least one titanium and at least one zirconium compound, in particular as complex fluorides significantly improves the properties, in particular of the coatings produced therewith.
• the various additives thus surprisingly act as in a modular system and contribute to the optimization of the respective coating significantly.
• the aqueous silane-based pretreatment composition has proven very useful, since it can be specifically optimized with the various additives to the respective multi-metal mix and its characteristics and requirements.
• a mix of various metallic materials may be coated with the aqueous silane-based pretreatment composition in the same bath, e.g. in bodies or in different small parts.
• substrates with metallic surfaces selected from cast iron, steel, aluminum, aluminum alloys, magnesium alloys, zinc and zinc alloys in any mix can be coated simultaneously and / or sequentially according to the invention, wherein the substrates can be at least partially metallically coated and / or at least partially can consist of at least one metallic material.
• the remainder is 1000 g / L of water or of water and at least one organic solvent such as e.g. Ethanol, methanol, isopropanol or dimethylformamide (DMF).
• organic solvents e.g. Ethanol, methanol, isopropanol or dimethylformamide (DMF).
• the content of organic solvents is particularly low or zero in most embodiments. Due to the hydrolysis of the at least one silane contained, a content in particular of at least one alcohol, e.g. Ethanol or / and methanol occur. It is particularly preferred to add no organic solvent.
• the aqueous silane-based pretreatment composition is free of or substantially free of all types of particles or particles larger than 0.02 micron mean diameter, which could be optionally added, for example, based on oxides such as SiO 2 . It is also free from additives in some compositions organic monomers, oligomers, polymers, copolymers or / and block copolymers.
• the applied siloxane / polysiloxane-containing coating is preferably applied fresh or / and may not or only slightly dry when rinsed.
• the coating is preferably rinsed within 20 seconds of application. Since the silane-containing aqueous composition when applied preferably has a temperature in the range of 10 to 50 ° C, more preferably in the range of 15 to 35 ° C, and also because the object to be coated preferably has a temperature in the range of 10 to 50 ° C. , more preferably in the range of 15 to 35 ° C, these temperatures are usually not so high and usually not so different that rapid drying of the wet film occurs.
• the aqueous silane-based pretreatment composition is poor, substantially free, or free of higher levels or levels of water-hardening agents, such as calcium contents above 1 g / L.
• water-hardening agents such as calcium contents above 1 g / L.
• it is free or low in lead, cadmium, chromate, cobalt, nickel or / and other toxic heavy metals.
• such substances are not intentionally added, but at least one heavy metal dissolved out of a metallic surface, for example, be introduced from another bath can and / or can occur as an impurity.
• the composition is poor in, substantially free of, or wholly free of bromide, chloride, and iodide, as they may possibly contribute to corrosion.
• the layer thickness of the coatings prepared with the aqueous silane-based pretreatment composition is preferably in the range of 0.005 to 0.3 .mu.m, more preferably in the range of 0.01 to 0.25 .mu.m, most preferably in the range of 0.02 to 0.2 ⁇ m, many at about 0.04 ⁇ m, at about 0.06 ⁇ m, at about 0.08 ⁇ m, at about 0.1 ⁇ m, at about 0.12 ⁇ m, at about 0.14 ⁇ m, at about 0.16 ⁇ m or about 0.18 ⁇ m.
• the organic monomer, oligomer, polymer, copolymer or / and block copolymer containing coatings are often somewhat thicker than those free or nearly free thereof.
• a coating is formed having a coating weight based on only the content of titanium and / or zirconium in the range of 1 to 200 mg / m 2 calculated as elemental titanium.
• This layer weight is particularly preferably in the range from 5 to 150 mg / m 2 , very particularly preferably in the range from 8 to 120 mg / m 2 , in particular at about 10, about 20, about 30, about 40, about 50, about 60, about 70, about 80, about 90, about 100 or about 110 mg / m 2 .
• a coating is formed having a coating weight which, based on only siloxanes / polysiloxanes, is in the range from 0.2 to 1000 mg / m 2 calculated as the corresponding largely condensed polysiloxane.
• This layer weight is particularly preferably in the range from 2 to 200 mg / m 2 , very particularly preferably in the range from 5 to 150 mg / m 2 , in particular at about 10, about 20, about 30, about 40, about 50, about 60, about 70, about 80, about 90, about 100, about 110, about 120, about 130 or about 140 mg / m 2 .
• the fluid used is preferably a liquid particle-free fluid, in particular water or a solution.
• the fluid is particularly preferably water of city water quality, a pure water quality such as fully demineralized water (deionized water) or a water quality with a content of eg at least one surfactant.
• a surfactant can cause homogenization of the wet film.
• the surfactant may be added to the water, which may also be an aqueous rinse solution, as surfactant mixture, wherein preferably an aqueous solution containing at least one surfactant and optionally also containing at least one additive such as at least one solubilizer, at least one surface-active substance such as a phosphonate, can be used on at least one of the electrodeposition coating and / or the electrodeposition coating substance.
• a surfactant it is obvious that basically any surfactant can be added, nonionic surfactants such as, for example, fatty alcohol polyglycol ethers being particularly preferred.
• the at least one surfactant can in principle be selected from the group of anionic, cationic, nonionic, amphoteric and other surfactants such as low-foam block copolymers. It may be advantageous to use a combination of at least two surfactants or at least three surfactants.
• a combination of surfactants from different classes of surfactants can be selected, for example, one or two nonionic surfactants together with a cationic surfactant. At least two chemically different surfactants are particularly preferably selected from the nonionic surfactants.
• a combination of at least one surfactant per class selected from the classes of anionic, cationic, nonionic, amphoteric and other surfactants is particularly preferred, in particular a combination of at least one nonionic surfactant with at least one surfactant from a different surfactant class.
• only nonionic surfactants can be used in combination.
• the nonionic surfactants are selected from straight-chain ethoxylates and / or propoxylates and preferably those having alkyl groups of 8 to 18 carbon atoms.
• surfactants are used with a cloud point, ie surfactants nonionic nature, it is advantageous that these surfactants are no longer above the cloud point in dissolved form in the washing medium of the washing process to minimize foaming, especially during spraying.
• a mixture of an ethoxylated alkylamine together with at least one ethoxylated or ethoxylated-propoxylated alkyl alcohol to set a low foaming tendency be particularly advantageous.
• the wetting and defoaming properties such as the rinsing of the rinse water and low foaming can be optimized, but surprisingly also the same properties of electrocoating as visual impression of the electrodeposition coating such as unevenness and streaking, uniformity of the layer thicknesses of Electrocoating, Improvement of the Lackumgriffs in the electrocoating especially at hintergriffigen points to coating substrate and the avoidance of markings are favorably influenced.
• At least one solubilizer such as, for example, cumene sulfonate or a glycol, in particular a dipropylene glycol, a polyglycol, a polyacrylamide or / and a modified polyacrylamide, a biocide, a fungicide or / and a means for adjusting the pH.
• a solubilizer such as, for example, cumene sulfonate or a glycol, in particular a dipropylene glycol, a polyglycol, a polyacrylamide or / and a modified polyacrylamide, a biocide, a fungicide or / and a means for adjusting the pH.
• Value such as an amine or an inorganic or / and organic acid used in the rinse water.
• a method is preferred in which an addition to the rinse water is used for rinsing the silane-based pretreatment coating, wherein the wetting and defoaming properties are simultaneously improved by the combination of at least two different surfactants and optionally further additives such as solubilizers.
• an additive with a content of surfactant in the rinse water is used for rinsing the silane-based pretreatment coating, by means of which the properties of the electrodeposition coating and of the electrodeposition coating are advantageously influenced.
• the electrocoated substrates, the aqueous silane-based pretreatment coating were rinsed with a surfactant-containing water, also showed a much better Lackumgriff than the non-surfactant-containing water rinsed electrocoated substrates.
• the content of the surfactants in the rinse water for rinsing after the silane-based pretreatment is preferably in the range from 0.001 to 1.6 g / L, particularly preferably in the range from 0.01 to 1.0 g / L or from 0.05 to 0.6 g / L.
• any type of electrodeposition paint can be used as electrodeposition paint in the process according to the invention.
• the coatings prepared with the aqueous silane-based pretreatment composition according to the invention and then with an electrodeposition paint can then be coated with at least one primer, lacquer, adhesive or / and with a lacquer-like organic composition, where appropriate at least one of these further coatings is cured by heating and / or irradiation.
• an aqueous treatment containing at least one water-dissolved iron compound may be carried out before the pretreatment with the silane-based composition.
• This composition is preferably alkaline, in particular in a pH range of 9 to 14.
• This composition can be, for example, an alkaline cleaner which is used in at least one process stage and which has a content of at least one iron compound in at least one process stage.
• this composition may also be free of some or all of the additives of a typical cleaner, for example, as an iron-containing aqueous rinse; this can then be used before, in between or after cleaning steps.
• this composition When applied to metallic surfaces, this composition may in principle have a temperature> 0 ° C. and ⁇ 100 ° C., in particular, as a cleaning composition, it may have a temperature in the range from 32 to 78 ° C. and particularly preferably in the range from 38 to 70 ° C or in the range of 40 to 60 ° C.
• the at least one iron compound is preferably at least one water-dissolved Fe 2+ compound or / and at least one water-soluble Fe 3+ compound.
• the total water-dissolved Fe content of the aqueous composition and the total Fe content of the aqueous composition are preferably in a range of 0.005 to 1 g / L.
• the contents of water-dissolved Fe 2+ compound are particularly preferably in the range from 0 to 0.5 g / L and the contents of water-dissolved Fe 3+ compound in the range from 0.003 to 0.5 g / L.
• the water-soluble Fe compounds may be added in particular as water-soluble salts such as sulfates and nitrates.
• the pretreatment step it is possible to reduce the pretreatment step from 3 to 5 minutes in phosphating to about 2 minutes when coating with silane-based coatings and to heating as in phosphating to temperatures often in the range of 50 to 60 ° C without.
• the bath temperature is preferably heated to temperatures in the range of 15 to 25 ° C.
• An addition of manganese to the aqueous silane-based pretreatment composition has surprisingly been found to be particularly advantageous: Although apparently no or almost no manganese compound is deposited on the metallic surface, the additive promotes the deposition of silane / silanol / siloxane / polysiloxane on the strong metallic surface. With the addition of nitroguanidine, it was surprisingly found that the appearance of the coated sheets is very uniform, especially on sensitive surfaces such as sandblasted iron or steel surfaces. An addition of nitrite has unexpectedly significantly reduced the potential for steel substrates.
• each additive having a significant positive effect which is mentioned in this application, has an additive effect for improving the coating according to the invention:
• the various properties, in particular of a multimetal system can be further optimized.
• the aqueous bath compositions are prepared as mixtures according to Table 2 using pre-hydrolyzed silanes. They each contain a silane and optionally also low levels of at least one similar further silane, which is also simplistic silane and not silane / silanol / siloxane / polysiloxane is spoken of and usually being this variety of compounds, sometimes in larger numbers similar compounds, also pulls into the formation of the coating, so that there are often several similar compounds in the coating. Depending on the silane, prehydrolyzing may also take several days at room temperature with vigorous stirring, as long as the silanes to be used are not already prehydrolyzed.
• the silane is added in excess to water and optionally catalysed with acetic acid.
• acetic acid was added only in some embodiments.
• acetic acid is already included as a catalyst for the hydrolysis. Ethanol is formed during hydrolysis but is not added. The finished mixture is used fresh.
• the sheets of the inventive examples are rinsed immediately after the aqueous silane-based pretreatment and immersed in the KTL bath immediately after rinsing. Afterwards, these sheets were provided with a complete, commercially used automotive paint finish (electrodeposition paint, filler, topcoat or clearcoat, total including KTL about 105 ⁇ m thickness of the layer package) and tested for their corrosion protection and their paint adhesion.
• the compositions and properties of the treatment baths as well as the properties of the coatings are summarized in Table 2.
• the organofunctional silane A is an amino-functional trialkoxysilane and has one amino group per molecule. Like all of the silanes used in this case, it is largely or approximately completely hydrolyzed in the aqueous solution.
• the organofunctional silane B has one terminal amino group and one ureido group per molecule.
• the non-functional silane C is a bis-trialkoxysilane; the corresponding hydrolyzed molecule has up to 6 OH groups on two silicon atoms.
• the complex fluorides of titanium or zirconium are used largely on the basis of a MeF x complex such as MeF 6 complex.
• Manganese and optionally low levels of at least one other cation, which is not mentioned in the table are added as metallic manganese of the respective complex fluoride solution and dissolved therein. This solution is mixed into the aqueous composition. If no complex fluoride is used, manganese nitrate is added.
• the silylated epoxy polymer has a low content of OH-- and isocyanate groups and is therefore subsequently also chemically crosslinkable at temperatures above 100 ° C.
• the silanes contained in the aqueous composition - concentrate or / and bath - are monomers, oligomers, polymers, copolymers or / and reaction products with other components due to hydrolysis reactions, condensation reactions or / and further reactions.
• the reactions take place above all in the solution, during drying or optionally also during curing of the coating, in particular at temperatures above 70 ° C. All concentrates and baths were stable for over a week with no changes and no precipitation. No ethanol was added. Levels of ethanol in the compositions come only from chemical reactions.
• the pH is adjusted in most examples and comparative examples, in the presence of at least one complex fluoride with ammonia, in other cases with an acid. All bathrooms show a good quality of the solution and almost always good bath stability. There are no precipitations in the baths.
• rinsing is first carried out once with deionised water. The freshly applied wet film was not allowed to dry any more because it was rinsed within 5 seconds after the application of the silane-containing coating. Both the freshly coated substrate and the rinse water were at room temperature. To avoid the entry of substances of the pretreatment solution in the subsequent coating bath, was a rinse necessary.
• the freshly rinsed coated substrate was then immersed directly in the cathodic dip, so that no further drying could occur.
• the coated sheets of Comparative Examples were dried immediately after rinsing at 120 ° C in a drying oven for 5 minutes, but the examples of the invention were coated without dipping immediately immediately afterwards with a cathodic dip paint by immersion.
• the visual inspection of the coatings can only be significantly carried out on the coatings on steel due to the interference colors and allows the uniformity of the coating to be assessed.
• the coatings without any complex fluoride content are quite uneven.
• a coating with titanium and with zirconium complex fluoride has surprisingly been found to be significantly more uniform than if only one of these complex fluorides had been applied.
• Addition of nitroguanidine, nitrate or nitrite also improves the uniformity of the coating. Partly the layer thickness increases with the concentration of these substances.
• Table 2 ⁇ / u> Compositions of baths in g / L based on solids contents, for silanes based on the weight of the hydrolyzed silanes; Residual content: water and usually a very small amount of ethanol; Process data and properties of the coatings Examples / VB VB 1 B1 VB 2 B2 VB 3 B 3 VB 4 B 4 VB 5 B 5 VB 6 B6 VB 7 B7 VB 8 B8 VB 9 B 9 Organofunkt.
• Silane A 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.1 0.1 0.3 0.3 0.2 0.2 0.2 0.2 H 2 TiF 6 as Ti - - 0.2 0.2 - - 0.2 0.2 0.2 0.1 0.1 0.3 0.2 0.2 0.2 H 2 ZrF 6 as Zr - - - - 0.2 0.2 0.2 0.2 0.1 0.1 0.3 0.3 0.4 0.4 0.2 0.2 Mn - - - - - - - - - - - 0.3 0.3 - - Silyl.
• the coating weight varies not only with the contents of the individual components of the aqueous solutions, but also with the type of the respective metallic surface being coated.
• the bath compositions are all stable and easy to apply in the short time of use. There are no differences in behavior, visual impression and test results between the various examples and comparative examples that can be attributed to treatment conditions such as application by syringes, dipping or roller coater treatment.
• the resulting films are transparent and almost all are largely uniform. They show no coloring of the coating.
• the resulting films are transparent and almost all are largely uniform.
• the structure, the gloss and the color of the metallic surface appear only slightly changed by the coating.
• With a content of titanium or / and zirconium complex fluoride iridescent layers are formed, in particular, on steel surfaces.
• the combination of several silanes has not yet resulted in any further significant improvement in the corrosion protection in the previous experiments; however, this can not be ruled out.
• a content of H 3 AlF 6 was determined on aluminum-rich metallic surfaces due to corresponding reactions in the aqueous composition.
• the combination of two or three complex fluorides in the aqueous composition has
• the layer thickness of the coatings produced in this way also depended on the type of application, which was initially varied in separate experiments, in the range from 0.01 to 0.16 ⁇ m, usually in the range from 0.02 to 0.12 ⁇ m at up to 0.08 microns, which was significantly larger with the addition of organic polymer.
• the corrosion protection grades are in the cross-cut test according to DIN EN ISO 2409 after storage for 40 hours in 5% NaCl solution according to BMW specification GS 90011 from 0 to 5, where 0 represents the best values.
• the rockfall test in accordance with DIN 55996-1, the coated sheets are bombarded with steel shot for 10 cycles following the above-mentioned VDA change test: the damage pattern is characterized by characteristic values from 0 to 5, with 0 indicating the best results.
• the coated sheets are exposed to a corrosive sodium chloride solution by spraying for up to 1008 hours; then the infiltration in mm is measured from the scratch, the scratch is made with a standardized stylus to the metallic surface and wherein the infiltration should be as small as possible.
• the coated aluminum alloy sheets are exposed to a special corrosive atmosphere by spraying for over 504 hours; then the infiltration is measured in mm from the scratch, which should be as small as possible.
• compositions of Examples and Comparative Examples B 10 to B 18 and VB 10 to VB 12 and VB15 to VB18 were prepared and used in the same manner as the other examples and comparative examples, except that in the second series only cold rolled steel ( CRS) and, in the third series, hot dip galvanized steel sheets were treated and that the panels treated with the silane containing composition were stored after flushing for 0.5 minutes for 30 minutes in room air at room temperature before being mixed with a commercially used cathodic Dipcoat (Electrocoating, e-coat, KTL) were dipped at 250V (2nd series) or 240V (3rd series).
• CRS cold rolled steel
• KTL cathodic Dipcoat
• the half-hour waiting period simulates the cycle time of such coated bodies to the introduction of the body in the KTL basin.
• the silane-containing coatings dried somewhat, but not completely through.
• the silane pretreatment of these Examples and Comparative Examples is based on the composition of B 8 and VB 8 wherein in the third series aqueous silane-based pretreatment compositions as in B 8 and VB 8 were used but still 0.001 to 0.10 g / L Cu and 0.1 to 1 g / L Zn and possibly also traces of Al and small amounts of Fe contained. The pH was also adjusted to 4.
• the fully desalted water for rinsing was prepared in the inventive examples with an addition of at least one surfactant, wherein the surfactant or the surfactant mixture as aqueous Solution was added.
• the surfactant mixture A contains a nonionic surfactant based on a fatty alcohol polyglycol ether.
• the surfactant mixture B contains a different type of nonionic surfactant and a solubilizer.
• the surfactant mixture B proved to be particularly favorable for the rinsing of the rinse water.
• the surfactant mixture C contains a nonionic surfactant based on an alkylamine.
• the surfactant mixture D contains a nonionic surfactant and a cationic surfactant.
• the addition 1.) is a water-soluble diphosphonic acid with a longer alkyl chain.
• the addition 2.) is a water-soluble tin compound.
• All KTL layers of a series were applied with the same tension, even if they differed significantly in the layer thicknesses.
• the KTL layers of the 2nd series were basically a bit too thick.
• the layer thicknesses were formed not only on the electrical conductivity of the pretreated substrate, but apparently also more on the quality of the remaining pretreatment layer, which apparently differed in their uniformity due to the different rinse compositions.
• the conditions were chosen so that inhomogeneities of the electrocoating paint were clearly visible and a differentiation of the quality of the cathodic electrocoating layer was possible.
• the corrosion resistance was determined in the salt spray test according to DIN EN ISO 9227 over 1008 hours, the paint adhesion by Cross-hatching method according to a 240-hour constant climate test according to DIN EN ISO 6270-2 and according to DIN EN ISO 2409. For both methods of analysis, the smaller values are the better values.
• nonionic surfactants are preferred, but it is beneficial in applications that can easily lead to foaming as in rinsing by spraying, low-foaming or little or almost non-foaming surfactants and / or surfactant-containing mixtures which may additionally contain, for example, a defoamer and / or a solubilizer and individually or in combination a low, a very low or almost no tendency to foaming eg have in injection processes.
• the nonionic surfactants are selected from straight-chain ethoxylates and / or propoxylates, preferably those having alkyl groups of 8 to 18 carbon atoms.
• the latter also includes the surfactants A, B and D.
• the surfactants A, B and D With such a combination of surfactants, the wetting and defoaming properties can be optimized at the same time, but also, surprisingly, several properties of the electrodeposition coating and electrodeposition coating can advantageously be influenced.
• no plastic markings may occur on bodyworks for automobiles in the Base Coat or / and in the Top Coat, as these usually give rise to intensive mechanical reworking and repainting.
• a pretreatment before applying the first coat eg a pretreatment composition based on at least one silane or on the basis of at least one silane a titanium or / and zirconium compound and / or with organic polymer.
• Such rework not only disturbs the workflow, but causes considerable costs, especially due to manual work.
• the electrocoated substrates, the aqueous silane-based pretreatment coating were rinsed with a surfactant-containing water, a much better Lackumgriff than the non-surfactant-containing water rinsed electrocoated substrates.
• those metallic components can be electrocoated with good results in which problems without the surfactant content in the water rinse and without the addition of an iron-containing treatment before the silane-based pretreatment occurred.
• an aqueous treatment containing a water-dissolved iron compound may be carried out before the pretreatment with the silane-based composition.
• the encapsulation of the electrodeposition coating layer is also correspondingly lower. Therefore, it is desirable to be able to use a higher voltage than, for example, 250 V, without exceeding a layer thickness of the dried and baked electrodeposition coating layer of, for example, 20 ⁇ m.
• a nominal layer thickness of the dried and baked electrodeposition coating layer resulted externally when using about 250 V in electrodeposition coating. Lowering this layer thickness despite the use of 250 V in the electrodeposition coating suggests the possibility of using higher voltages, which then also lead to a higher throwover.
• the herein added surfactant E is a nonionic surfactant based on an alkyl ethoxylate having an alkyl group and having an end group seal, wherein a content of cationic compound has also been added.
• the pH of the cleaner was in Range of 10 to 11.
• a gluconate or / and a heptonate in the specified total amount was added as the complexing agent.
• the cleaner contained at least one alkali compound, which served to adjust the pH.
• Other variants which are not listed in detail in Table 4, relate to optional additions of boric acid or silicate and the further variation of all contents of the cleaner, all of which process variants led to the same or the same results. In comparison with all of these examples according to the invention, neither an Fe-containing cleaning nor a surfactant-containing rinse was used in Comparative Example 19.

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