Method for coating surfaces and use of the objects coated using said method

Abstract

A method for electroless coating of a substrate by applying an activating coat of polyelectrolyte or salt with a first aqueous composition, rinsing of the activating coat such that the activating coat is not entirely removed The activated surface that has remained after rinsing is then contacted with an aqueous composition in the form of a solution, emulsion or suspension to form an organic secondary coat (precipitation coat), and drying. The activating coat contains at least one cationic polyelectrolyte or at least one cationic salt in solution in water. The aqueous composition which forms the secondary coat contains constituents which can be precipitated, deposited and/or salted out and which are anionically, zwitterionically, sterically or cationically stabilized. The dry film formed in the process, which is made of the activating coat and the secondary coat, has a thickness of at least 1 m.

Claims

1. A method for coating a substrate, the method comprising the steps of: (I) providing the substrate; (II) optionally cleaning the substrate; (III) applying a first aqueous composition to form an activating coat on the substrate, the first aqueous composition comprising an activating agent comprising at least one cationic polyelectrolyte selected from the group consisting of a polyethyleneimine, a silane-modified polyethyleneimine, a polyethyleneimine modified with a silane compound, a polyvinylamine, a silane-modified polyvinylamine, a polyvinylamine modified with a silane compound, a chitosan, a silane-modified chitosan, and a chitosan modified with a silane compound; (IV) intermediate drying of the activating coat; (V) after the intermediate drying step, rinsing the activating coat, wherein when the activating coat is rinsed, at least a portion of the activating coat remains on the substrate; (VI) contacting and coating the remaining activating coat with a second aqueous composition to form an organic secondary coat, the second aqueous composition in at least one form selected from the group consisting of a solution, an emulsion and a suspension; (VII) optionally rinsing the organic secondary coat; and (VIII) drying the organic secondary coat; wherein the first aqueous composition is in the form selected from the group consisting of a solution, an emulsion and a suspension; wherein the second aqueous composition has constituents which can be precipitated, deposited, or salted out and which are stabilized in a manner selected from the group consisting of anionically, zwitterionically, sterically and cationically, where anionically stabilized and cationically stabilized constituents in the second aqueous composition do not adversely affect one another; wherein when a dry film is formed, the dry film comprises the organic secondary coat or the activating coat and the organic secondary coat, and the dry film has a thickness of at least 1 m; and wherein the activating coat or/and the organic secondary coat is/are electrolessly applied to the substrate.

2. The method of claim 1, wherein to form the activating coat at least one modified polyelectrolyte is used which has been modified with at least one member selected from the group consisting of a silane, a silanol and a siloxane with a degree of condensation in the range from 1 to 30.

3. The method of claim 1, wherein the activating agent is prepared using (a) at least one member selected from the group consisting of a siliane, a silanol, and a siloxane to modify (b) a polyethyleneimine, polyvinylamine or chitosan, wherein the molar ratio of (a):(b) is in the range from about 2,500:1 to about 10,000:1.

4. The method of claim 1, wherein in step (VI) the second aqueous composition is a formulation or a dispersion, the second aqueous composition selected from the group consisting of: A) anionically stabilized polymer particle dispersions, B) anionically stabilized formulations, C) sterically stabilized polymer particle dispersions, D) sterically stabilized formulations, E) zwitterionically stabilized polymer particle dispersions, F) zwitterionically stabilized formulations and mixtures thereof or selected from the group consisting of the following aqueous compositions: G) cationically stabilized polymer particle dispersions, H) cationically stabilized formulations, I) sterically stabilized polymer particle dispersions, J) sterically stabilized formulations, K) zwitterionically stabilized polymer particle dispersions, L) zwitterionically stabilized formulations and mixtures thereof.

5. The method of claim 1, wherein the contacting and coating during activating to form a secondary coat occurs in a dipping process.

6. The method of claim 1, wherein in step (I) the substrate is a metallic substrate, the metallic substrate selected from the group consisting of aluminum, iron, copper, magnesium, titanium, zinc and tin, or an alloy thereof containing a member selected from the group consisting of aluminum, iron, steel, copper, magnesium, nickel, titanium, zinc and tin.

7. The method of claim 1, wherein the substrate has been precoated and/or joined to a plastics component.

8. The method according to claim 1, wherein the activating agent is polyethyleneimine.

9. A method for coating a substrate, the method comprising the following steps: (I) providing the substrate; (II) optionally cleaning the substrate; (III) applying an activating coat; (IV) intermediately drying the activating coat; (V) rinsing the activating coat; (VI) coating the activating coat with a formulation or a dispersion to form an organic secondary coating; (VII) rinsing the organic secondary coating; (VIII) drying and/or crosslinking of the organic secondary coating; wherein the activating coat is formed from a compound or mixture of compounds selected from the group consisting of chitosan, calcium acetate, calcium formate, and mixtures thereof; and wherein the activating coat or/and the organic secondary coat is/are electrolessly applied to the substrate.

Description

DESCRIPTION OF THE FIGURES

(1) The invention is now elucidated with reference to the following, nonlimiting examples and to the figures, the figures showing SEM micrographs of the coat stack comprising cationic activating coat and of the secondary coat comprising originally anionically stabilized substances.

(2) FIG. 1 shows an SEM image of a substrate according to example B9, coated with activating agent 3, a silane group-modified polyethyleneimine, and having an activating coat comprising a silane-modified cationic polyelectrolyte with a dry film thickness of around 0.2 m.

(3) FIG. 2 shows an SEM image of a substrate coated with a secondary coat 1(30), without activating agent, as per comparative example VB13. The SEM micrograph shows a cleaned metal panel which without formation of an activating coat had been dipped into the aqueous composition, to form the secondary coat, and rinsed. Since there was no activating coat, there was also no formation of a secondary coat.

(4) FIG. 3 shows an SEM image of a substrate according to example B23, coated with activating agent 3 and a secondary coat 1(30), with dispersion 1 in a concentration of 30% by weight. Because of the activating coat, it was possible over 5 minutes to form a secondary coat with a dry film thickness of approximately 9 to 10 m.

(5) FIG. 4 shows an SEM image of a substrate according to example B26, coated with activating agent 3 and a secondary coat 1(20). For this purpose, the secondary coat was formed with dispersion 1 in a concentration of 20% by weight. Because of the activating coat, it was possible over 5 minutes to form a secondary coat with a dry film thickness of approximately 11 to 16 m. In spite of the lower concentration of dispersion 1 in comparison to FIG. 3, a significantly thicker secondary coat was formed.

(6) FIG. 5 shows an SEM image of a substrate according to example B26, coated with activating agent 3 and a secondary coat 11(20). For this purpose, the secondary coat was formed with dispersion 11 in a concentration of 20% by weight. Because of the activating coat, it was possible over 5 minutes to form a secondary coat with a dry film thickness of approximately 15 to 20 m. In spite of the equally high concentration of dispersion 11 in comparison to dispersion 1 from FIG. 4, a significantly thicker secondary coat was formed. This indicates that the dry film thickness, for a given deposition time, is dependent on specific physicochemical properties of the dispersion.

(7) FIG. 6 shows an SEM image of a substrate according to example B29, coated with activating agent 3 and a secondary coat 1(10). For this purpose the secondary coat was formed with dispersion 1 in a concentration of 10% by weight. Consequently almost all of the conditions are identical with those for FIGS. 3 and 4. Because of the activating coat, it was possible over 5 minutes to form a secondary coat having a dry film thickness of 60 to 64 m. In spite of the further-reduced concentration of dispersion 1 in comparison to dispersion 1 from FIGS. 3 and 4, a significantly thicker secondary coat was formed on the same substrate under otherwise identical conditions. This again indicates that the dry film thickness, for a given deposition time, is dependent on specific physicochemical properties of the dispersion.

(8) FIG. 7 shows an SEM image for example B47 with a secondary coat, for which a secondary coat was formed on an activating coat comprising cationic salt, the secondary coat having a thickness in the range from 59 to 64 m.

INVENTIVE EXAMPLES (B) AND COMPARATIVE EXAMPLES (VB)

(9) 1.) Examples B1 to B45 for Cationic Polyelectrolytes as Activating Agents:

(10) I. Substrate Type (Metal Sheets):

(11) 1: Electrolytically galvanized steel sheet with a zinc coat add-on of 5 m, sheet thickness 0.81 mm. 2: Hot-dip-galvanized steel sheet, sheet thickness about 0.8 mm. 3: Cold-rolled steel, sheet thickness about 0.8 mm. 4: Aluminum alloy of quality class AC 170, sheet thickness about 1.0 mm.

(12) Different kinds of aqueous formulations and dispersions were prepared for contacting and/or coating these sheets. The different substrates did not show any significant differences in coating behavior.

(13) II. Alkaline Cleaning:

(14) 1: 30 g/L alkaline, silicate-free cleaner Gardoclean S 5176 and also 4 g/L GardobondAdditive H 7406 for suppressing foaming during spraying, from Chemetall GmbH, were prepared in municipal water for a pH of 10.5, giving only a moderate pickling attack. The sheets were cleaned by spraying at 60 C. for 180 seconds, and then rinsed for 120 seconds with municipal water and thereafter for 120 seconds with deionized water, by dipping.
III. Activation:

(15) Activation is used to apply a homogeneous secondary coat, with the aqueous activating agent comprising the substances required for precipitation, coagulation, salting-out and/or deposition, and/or consisting, besides water, of the substances below. Coating took place with the following activating agents at room temperature over 2.5 minutes: 1: Cationic polyethyleneimine. Average molecular weight 750 000 Da. Amount of solids and active ingredients: 5% by weight. 2: Cationic polyethyleneimine. Average molecular weight 2 million Da. Amount of solids and active ingredients: 5% by weight. 3: Epoxysilane-modified cationic polyethyleneimine with an average molecular weight of about 2 million Da: in this case a pretreatment solution with a prehydrolyzed alkoxysilane having amino groups was mixed with a 5% strength polyethyleneimine solution in the presence of cations such as zirconium, and the mixture was then applied to the metallic substrate by dipping. However, the activating substance was not dried on the sheets, but was instead applied wet-on-wet without initial drying. In contrast to activating agent 2, no intermediate drying is necessary before the rinsing of the activating coat in order to form rinse-resistant activating coats. 3 (blade-coated): The same activating agent 3 was now applied by doctor blade. The necessary coat thickness of activator 3 was applied to the substrates in a controlled way by means of liquid application and doctor blade. In the case of examples 30 and 31 in table 3 it is made clear that by blade coating it is possible to set the thickness of the activating coat, but also that a thicker activating coat allows the formation of a thicker secondary coat. 4: Activation based on Oxsilan from Chemetallstatus as described in WO 2010/054985 A1comparative example. 5: Activation based on Oxsilan from Chemetallongoing development relative to status as described in WO 2010/054985 A1comparative example. 6: 5 g of copolymer of vinylpyrrolidone (VP) and quaternized vinylimidazole. Molar electrostatic capacity MEQ of the polyelectrolyte, with higher values often indicating a higher molecular charge. At pH 7:1.0 meq/g. Average molecular weight Mw=200 000 Da. Diluted in 100 mL of deionized water. Amount of solids and active ingredients: 13% by weight. 7: 5 g of copolymer of vinylpyrrolidone (VP) and quaternized vinylimidazole. MEQ at pH 7:3.0 meq/g. Mw=400 000 Da. Diluted in 100 mL of deionized water. Amount of solids and active ingredients: 20% by weight. 8: 5 g of copolymer of vinylpyrrolidone (VP) and quaternized vinylimidazole. MEQ at pH 7:6.1 meq/g. Mw=40 000 Da. Diluted in 100 mL of deionized water. Amount of solids and active ingredients: 40% by weight. 9: 5 g of copolymer of vinylcaprolactam (VCap), vinylpyrrolidone (VP), quaternized vinylimidazole (QVI). MEQ at pH 7:0.5 meq/g. Mw=700 000 Da. Diluted in 100 mL of deionized water. Amount of solids and active ingredients: 20% by weight. 10: Cationic polyvinylamine. Average molecular weight 45 000 Da., amount of solids and active ingredients: 5% by weight. 11: Cationic polyvinylamine. Average molecular weight 340 000 Da., amount of solids and active ingredients: 5% by weight. 12: Silane group-modified cationic polyvinylamineaverage molecular weight 340 000 Da. In this case a prehydrolyzed pretreatment solution with a prehydrolyzed alkoxysilane having amino groups was mixed with a 5% strength polyethyleneimine solution in the presence of cations such as zirconium, but not dried on the sheets (wet-on-wet application), and then applied to the metallic substrate by dipping. In contrast to activating agent 11, there is no need for intermediate drying before the activating coat is rinsed, in order to form rinse-resistant activating coats. 13: Aqueous solution consisting of chitosan from Sigma Aldrich HMW and Fluka LMW. pH: 3. Concentration of 1% by weight, molecular weight chitosan from 5000 g/mol to 2 000 000 g/mol. 14: Aqueous solution consisting of silane group-modified chitosan from Sigma Aldrich HMW and Fluka LMW. pH: 3. Concentration of 1% by weight, molecular weight of chitosan from 5000 g/mol to 2 000 000 g/mol. In this case a prehydrolyzed pretreatment solution based on an aminoalkoxysilane was mixed with a 5% strength chitosan solution in the presence of cations such as zirconium, but not dried, and was then applied wet-on-wet to the metallic substrate by dipping.
IV. Intermediate Drying of the Activating Coat:

(16) In the course of the experiments it was found that an intermediate drying step may possibly have an influence on the thickness of the secondary coat, since smaller amounts of the activating coat were removed in the subsequent rinsing step V after an intermediate drying. 1: Drying at 40 C. for 15 minutes in a drying cabinet with forced air and fresh-air supply.
V. Rinsing of the Activating Coat:

(17) One-fold rinsing by immersion of the coated substrates into a gently agitated bath of deionized water over 2 minutes at room temperature.

(18) Since part of the fresh coating is rinsed off in the course of the rinsing operation, in some outcomes the remaining amounts of the activating coat were ascertained, together with element amounts of the remainders of cleaning agents, of the pretreatment coat, of the anticorrosion primer coat, etc. It proved advantageous if as high as possible a fraction of the activating coat is retained during rinsing.

(19) The amounts of elements in the activating coat were determined by means of X-ray fluorescence analysis (XFA) for the activating coat, including the amounts from previous treatmentswhere present. The figures relate to the element contents after rinsing. With these figures it was possible to estimate the remaining coat thicknesses and to compare them from sample to sample, it being made clear that in spite of intensive rinsing, comparatively high fractions of the activating coat are retained. These amounts are sufficient to provide the activated surface with effective preparation for the subsequent treatment steps VI. and VII.

(20) Parallel investigations by scanning electron microscopy (SEM) made it clear that impervious coatings were formed from the combination of the contacting with activating agent and subsequent coating with the formulation for the secondary coat.

(21) VI. Coating of the Activated Surfaces with Formulations and/or Dispersions for Forming a Secondary Coat:

(22) The secondary coat was formed by dipping the coated substrate into a gently agitated bath of the dispersion or formulation at room temperature for 5 minutes in each case.

(23) An indication such as, for example, 1(30) is intended here to show that composition 1 is used in a concentration of 30% by weight of the solids and active ingredients.

(24) A) Anionically Aqueous Polymer Particle Dispersions:

(25) 1 (30): Polyurethane dispersion A from Alberdingk-Boley. Average particle size d.sub.50 150 nm. Viscosity 20-400 mPa.Math.s. Zeta potential 50 mV. Minimum film-forming temperature 25 C. pH 7-8. Amount of solids and active ingredients 30% by weight. 1 (20): Polyurethane dispersion A from Alberdingk-Boley. Average particle size d.sub.50 150 nm. Viscosity 20-400 mPa.Math.s. Zeta potential 50 mV. Minimum film-forming temperature 25 C. pH 7-8. Amount of solids and active ingredients 20% by weight. 1 (10): Polyurethane dispersion A from Alberdingk-Boley. Average particle size d.sub.50 150 nm. Viscosity 20-400 mPa.Math.s. Zeta potential 50 mV. Minimum film-forming temperature 25 C. pH 7-8. Amount of solids and active ingredients 10% by weight. 2 (30): Oxidatively drying polyester-polyurethane dispersion B from Bayer Materials Science AG. Average particle size d.sub.50 125 nm. Viscosity 200-350 mPa.Math.s. Zeta potential 60 mV. Minimum film-forming temperature 10-15 C. pH 7.2. Amount of solids and active ingredients 30% by weight. 2 (20): Oxidatively drying polyester-polyurethane dispersion B from Bayer Materials Science AG. Average particle size d.sub.50 125 nm. Viscosity 200-350 mPa.Math.s. Zeta potential 60 mV. Minimum film-forming temperature 10-15 C. pH 7.2. Amount of solids and active ingredients 20% by weight. 2 (10): Oxidatively drying polyester-polyurethane dispersion B from Bayer Materials Science AG. Average particle size d.sub.50 125 nm. Viscosity 200-350 mPa.Math.s. Zeta potential 60 mV. Minimum film-forming temperature 10-15 C. pH 7.2. Amount of solids and active ingredients 10% by weight. 3 (20): Dispersion C based on polyacrylate. Average particle size d.sub.50 125 nm. Viscosity 400 mPa.Math.s. Zeta potential 65 mV. Minimum film-forming temperature 19 C. pH 8. Amount of solids and active ingredients 20% by weight. 4 (20): Dispersion D based on polyacrylate. Average particle size d.sub.50 150 nm. Viscosity 20 mPa.Math.s. Zeta potential 51 mV. Minimum film-forming temperature 40 C. pH 8. Amount of solids and active ingredients 20% by weight. 5 (20): Polyether-polyurethane dispersion E from Bayer Materials Science AG. Average particle size d.sub.50 250-500 nm. Viscosity 100 mPa.Math.s. Zeta potential 57 mV. Minimum film-forming temperature 20 C. pH 7-8.5. Amount of solids and active ingredients 20% by weight. 6 (20): Polyester-polyurethane dispersion F from Bayer Materials Science AG. Average particle size d.sub.50 200-400 nm. Viscosity 200 mPa.Math.s. Zeta potential 50 mV. Minimum film-forming temperature 25 C. pH 7-8. Amount of solids and active ingredients 20% by weight. 7 (20): Anionic and nonionic polyester-polyurethane dispersion G from Bayer Materials Science AG. Average particle size d.sub.50 140 nm. Viscosity 80 mPa.Math.s. Zeta potential 83 mV. Minimum film-forming temperature 30 C. pH 6-8. Amount of solids and active ingredients 20% by weight. 8 (20): Anionic and nonionic dispersion H from Bayer Materials Science AG. Average particle size d.sub.50 120 nm. Viscosity 110 mPa.Math.s. Zeta potential 80 mV. Minimum film-forming temperature 15 C. pH 7. Amount of solids and active ingredients 20% by weight. 9 (20): Anionic and nonionic dispersion I from Bayer Materials Science AG. Average particle size d.sub.50 170 nm. Viscosity 90 mPa.Math.s. Zeta potential 84 mV. Minimum film-forming temperature 30 C. pH 7. Amount of solids and active ingredients 20% by weight. 10 (20): Anionic and nonionic dispersion J from Bayer Materials Science AG. Average particle size d.sub.50 110 nm. Viscosity 40 mPa.Math.s. Zeta potential 82 mV. Minimum film-forming temperature 25 C. pH 7. Amount of solids and active ingredients 20% by weight.
B) Anionically Stabilized Aqueous Formulations: 11 (20): One-component, anionically stabilized paint formulation based on epoxy resin deposition paint. Amount of solids and active ingredients 20% by weight. 11 (10): One-component, anionically stabilized paint formulation based on epoxy resin deposition paint. Amount of solids and active ingredients 10% by weight. 12 (20): Anionic dispersion formulated with TiO.sub.2. Amount of solids and active ingredients 20% by weight. Average particle size d.sub.50 150 nm. 12 (10): Anionic dispersion formulated with TiO.sub.2. Amount of solids and active ingredients 10% by weight. Average particle size d.sub.50 150 nm.
VII. Rinsing of the Secondary Coat:
The purpose of rinsing after the secondary coat was to remove uncoagulated and/or unprecipitated constituents of the aqueous composition and their accumulations, and to make the procedure as close in reality as possible to the usual procedure in the automobile industry. The reason is that in the automobile industry, rinsing with water usually takes place either by dip rinsing or spray rinsing. Rinsing was carried out in each case once by dipping for 2 minutes at room temperature in deionized water.
VIII. Drying, Filming and/or Crosslinking of the Secondary Coat:

(26) Drying with filming in particular of the organic polymeric constituents: 1: Dried at 175 C. for 15 minutes in a drying cabinet with forced air and fresh-air supply with filming, since at the temperatures all examples gave a dry film which under the scanning electronmicroscope can no longer be resolved as a particulate coating.

(27) Parallel investigations by scanning electronmicroscopy (SEM) made it clear that in accordance with the invention, coatings were formed from which it was possible for largely impervious or impervious coatings to be formed from the combination of the contacting with activating agent and through contacting of the activated surfaces of dispersions and/or formulations. The micrographs consistently showed homogenous coat formation, thus demonstrating a reliable, self-regulating, and readily controllable coating method.

(28) If a secondary coat was formed on a thin activating coat which was not homogeneous and not impervious, the secondary coat, though thinner, was nevertheless formed homogeneously and imperviously. In certain of the experiments, coating took place only within a time of 2 or 3 minutes, although the selected 5-minute treatment time was retained, thus giving an end state of the secondary coat in 5 minutes' treatment time. The secondary coat formed was first rinsed and only thereafter dried. The rinsing of the secondary coat was used for removing excess substance of the aqueous composition, and impurities. Here it was ensured that the secondary coat has a few minutes' time prior to rinsing, within the treatment time, to allow satisfactory saturation of the polyelectrolyte with the organic matrix. In all of the experiments, 5 minutes were sufficient for this purpose. It is assumed that within this time the polyelectrolyte is enveloped with polymer, so that the secondary coat is formed rinse-resistantly. It was found that the secondary coats comprising modified polyelectrolyte were significantly more rinse-resistant than the secondary coats comprising unmodified polyelectrolyte. Nevertheless, the secondary coats comprising unmodified polyelectrolyte were sufficiently rinse-resistant for these experiments. Accordingly, the conditions are met to allow an electrodeposition coating process to be converted to an electroless process. Initial corrosion tests and adhesion tests demonstrate that the corrosion resistance and the paint adhesion of the coat system of the invention are within an order of magnitude fundamentally sufficient for the technical purpose. In the wide variety of experiments, it was possible to form secondary coats with a dry film thickness of up to 38 m in 5 minutes' treatment time in each case, whereas the formation of an electrodeposition coat of around 20 m took 10 to 20 minutes, with a high level of current consumption. As a result, it is possible, in an environmentally friendly way, to avoid high energy quantities and a costly and inconvenient plant engineering.

(29) Tables for Examples B1-B12, B21-B31 and B34-45:

(30) TABLE-US-00001 TABLE 1 Verification of the rinse resistance of the modified polyethyleneimine activation Example B1 B2 B3 B4 B5 B6 Substrate type No.: 1 2 3 4 1 2 Alkaline cleaning No.: 1 1 1 1 1 1 Activation Activating agent No.: 1 1 1 1 2 2 Intermediate drying of the activating coat No.: Rinse resistance: no no no no no no XFA element amounts /// /// /// /// /// /// [mg/m.sup.2] Si/Ti/Zr/Mn SEM coat thickness dry 0 0 0 0 0 0 film [m] Secondary coat Secondary coat No.: Rinse resistance 2: Drying No.: SEM coat thickness dry film [m] Example B7 B8 B9 B10 B11 B12 Substrate type No.: 3 4 1 2 3 4 Alkaline cleaning No.: 1 1 1 1 1 1 Activation Activating agent No.: 2 2 3 3 3 3 Intermediate drying of the activating coat No.: Rinse resistance: no no yes yes yes yes XFA element amounts /// /// 21/<1/ 18/<1/ 22/<1/ 30/5/ [mg/m.sup.2] Si/Ti/Zr/Mn 82/149 75/52 82/>200 80/122 SEM coat thickness dry 0.2 0.2 0.2 0.1 film [m] Secondary coat Secondary coat No.: Rinse resistance 2: Drying No.: SEM coat thickness dry film [m]

(31) TABLE-US-00002 TABLE 2 Inventive examples with polyethyleneimine and with intermediate drying in the case of unmodified polyethyleneimine Example B21 B22 B23 B24 B25 B26 B27 B28 B29 Substrate type No.: 1-4 1-4 1-4 1-4 1-4 1-4 1-4 1-4 1-4 Alkaline cleaning 1 1 1 1 1 1 1 1 1 No.: Activation Activating agent 1 2 3 1 2 3 1 2 3 No.: Intermediate drying 1 1 1 1 1 1 of the activating coat No.: Rinse resistance: yes yes yes yes yes yes yes yes yes XFA element /// /// /// /// /// /// /// /// /// amounts [mg/m.sup.2] Si/Ti/Zr/Mn SEM coat thickness 0.1-0.2 0.1-0.2 0.2 0.1-0.2 0.1-0.2 0.2 0.1-0.2 0.1-0.2 0.2 dry film [m] Secondary coat Secondary coat No.: n(30); n = 1, 2 n(20); n = 1, . . . 11, 12 n(10); n = 1, 2, 11, 12 Rinse resistance 2: yes yes yes yes yes yes yes yes yes Drying No.: 1 1 1 1 1 1 1 1 1 SEM coat thickness 3-6 4-7 5-10 10-15 10-15 11-16 23-30 23-30 25-31 dry film [m]

(32) TABLE-US-00003 TABLE 3 Additional inventive examples with modified polyethyleneimine, to show the correlating coat thicknesses of the activating coat and the secondary coat Example B30 B31 Substrate type No.: 1, 2 1, 2 Alkaline cleaning No.: 1 1 Activation Activating agent No.: 3 (blade-coated) 3 (blade-coated) Intermediate drying of the 3 3 activating coat No.: Rinse resistance: yes yes XFA element amounts [mg/m.sup.2] /// /// Si/Ti/Zr/Mn SEM coat thickness dry film [m] 0.01-0.05 0.3-0.4 Secondary coat Secondary coat No.: n(20); n = 1, 11 Rinse resistance 2: yes yes Drying No.: 1 1 SEM coat thickness dry film [m] 3-5 20-25

(33) TABLE-US-00004 TABLE 4 Inventive examples with modified polyelectrolytes and with intermediate drying Example B34 B35 B36 Substrate type No.: 1-4 1-4 1-4 Alkaline cleaning No.: 1 1 1 Activation Activating agent No.: 3 3 3 Intermediate drying of the 1 1 1 activating coat No.: Rinse resistance: yes yes yes XFA element amounts /// /// /// [mg/m.sup.2] Si/Ti/Zr/Mn SEM coat thickness dry film 0.3 0.3 0.3 [m] Secondary coat Secondary coat No.: n(30); n(20); n(10); n = 1, 2 n = 1, 11 n = 1, 11 Rinse resistance 2: yes yes yes Drying No.: 1 1 1 SEM coat thickness dry film 10-11 20-25 25-30 [m]

(34) TABLE-US-00005 TABLE 5 Inventive examples with copolymers of vinylpyrrolidone and quaternary vinylimidazole and with intermediate drying Example B37 B38 B39 B40 Substrate type No.: 1-4 1-4 1-4 1-4 Alkaline cleaning No.: 1 1 1 1 Activation Activating agent No.: 6 7 8 9 Intermediate drying of the 1 1 1 1 activating coat No.: Rinse resistance: yes yes yes yes XFA element amounts /// /// /// /// [mg/m.sup.2] Si/Ti/Zr/Mn SEM coat thickness dry 0.03-0.04 0.03-0.04 0.01-0.02 0.01-0.02 film [m] Secondary coat Secondary coat No.: 1(20) Rinse resistance 2: yes yes yes yes Drying No.: 1 1 1 1 SEM coat thickness dry film 1-2 2-3 1-2 2-3 [m]

(35) TABLE-US-00006 TABLE 6 Inventive examples with pure and with modified polyvinylamines Example B41 B42 B43 Substrate type No.: 1-4 1-4 1-4 Alkaline cleaning No.: 1 1 1 Activation Activating agent No.: 10 11 12 Intermediate drying of the 1 1 activating coat No.: Rinse resistance: yes yes yes XFA element amounts /// /// /// [mg/m.sup.2] Si/Ti/Zr/Mn SEM coat thickness dry film 0.08-0.1 0.08-0.1 0.1-0.2 [m] Secondary coat Secondary coat No.: 1(20) Rinse resistance 2: yes yes yes Drying No.: 1 1 1 SEM coat thickness dry film 3-4 6-7 8-10 [m]

(36) TABLE-US-00007 TABLE 7 Inventive examples with pure and with modified chitosan Example B44 B45 Substrate type No.: 1-4 1-4 Alkaline cleaning No.: 1 1 Activation Activating agent No.: 13 14 Intermediate drying of the 1 activating coat No.: Rinse resistance: yes yes XFA element amounts [mg/m.sup.2] /// /// Si/Ti/Zr/Mn SEM coat thickness dry film 0.5-1.0 0.3-0.5 [m] Secondary coat Secondary coat No.: 1(20) Rinse resistance 2: yes yes Drying No.: 1 1 SEM coat thickness dry film 8-9 4-5 [m]
Tables for Comparative Examples VB13-VB20 and VB32-VB33;

(37) TABLE-US-00008 TABLE 8 Verification that without an activating coat no secondary coat is formed, but also that, at the concentration and viscosity of the dispersion that are used, no secondary coat is formed, owing to a viscosity effect. Example VB13 VB14 VB15 VB16 VB17 VB18 VB19 V20 Substrate type No.: 1 2 3 4 1 2 3 4 Alkaline cleaning No.: 1 1 1 1 1 1 1 1 Activation Activating agent No.: Intermediate drying of the activating coat No.: Rinse resistance: XFA element amounts [mg/m.sup.2] <1/<1/ <1/<1/ <1/<1/ 10/6/ <1/<1/ <1/<1/ <1/<1/ 9/6/ Si/Ti/Zr/Mn <1/17 <1/5 <1/78 <1/23 <1/19 <1/6 <1/77 <1/20 SEM coat thickness dry film [m] Secondary coat Secondary coat No.: 1(30) 1(30) 1(30) 1(30) 11(20) 11(20) 11(20) 11(20) Rinse resistance 2: no no no no no no no no Drying No.: 1 1 1 1 1 1 1 1 SEM coat thickness dry 0 0 0 0 0 0 0 0 film [m]

(38) TABLE-US-00009 TABLE 9 Current maximum achievable dry film thicknesses of the total coat system with silane activation of the technology according to WO 2010/054985 A1 Example VB32 BB33 Substrate type No.: 1, 2 1, 2 Alkaline cleaning No.: 1 1 Activation Activating agent No.: 4 5 Intermediate drying of the activating coat No.: Rinse resistance: yes yes XFA element amounts [mg/m.sup.2] /// /// Si/Ti/Zr/Mn SEM coat thickness dry film [m] Secondary coat Secondary coat No.: n(20); n = 1, 11 Rinse resistance 2: yes yes Drying No.: 1 1 SEM coat thickness dry film 0.5 1-2 [m]
2.) Examples B46 and B47 for Cationic Salts as Activating Agents:

(39) The same production sequence was selected under the same conditions as for the unmodified cationic polyelectrolytes. In step III., however, an activation based on cationic salts was used, comprising the activating substances necessary for the subsequent precipitation reactions and/or coagulation, and/or consisting of the substances. The activating coat was always formed over 2.5 minutes. 15: 1-molar aqueous solution in deionized water of calcium acetate. 16: 1-molar aqueous solution in deionized water of calcium formate.

(40) These salt-containing activating coats were in this case dried at 40 C. for 15 minutes in a drying cabinet with forced air and fresh-air supply, before the coated substrates were rinsed as for the cationic polyelectrolytes.

(41) To form a secondary coat, the dispersion 1 (20) was used, with a solids and active ingredient content of 20% by weight, as for the cationic polyelectrolytes. In this case, over 5 minutes' coating time at room temperature, a secondary coat was formed which had a dry film thickness in the range from 30 to 35 or from 59 to 64 m, respectively. Here it was found that the cationic salts not only have fundamentally the same kind of effect as, for example, cationic polyelectrolytes, but are also able to form secondary coats of equal thickness or even of substantially greater thickness. The high or very high dry film thickness, respectively, is associated on the one hand with the divalent salt of the activating agent, and on the other hand possibly with the physicochemical properties of the formate.

(42) TABLE-US-00010 TABLE 10 for B46 and B47: Example B46 B47 Substrate type: 1-4 1-4 Cleaning: Alkaline cleaning No. 1 1 Activation: Activating agent No. 15 16 Intermediate drying of the activating coat: Drying No. 1 1 Properties after rinsing of the activating coat: Rinse resistance yes yes XFA element amounts mg/m.sup.2: Si Ti Zr Mn SEM coat thickness dry film [m] 0.1-0.2 0.1-0.2 Secondary coating Formulation/dispersion No. 1(20) 1(20) Rinsing of the secondary coating Rinse resistance yes yes Drying/crosslinking of the coating Drying No. 1 1 SEM coat thickness dry film [m] 30-35 59-64
3.) Examples B48 to B58 on the Use of Similarly Charged Activating Coats and Substances for a Secondary Coat:

(43) These fundamental experiments serve to show that a cationic activating agent can also precipitate a cationically stabilized dispersion, and that an anionic activating agent can also precipitate an anionically stabilized dispersion. The production cycle used was fundamentally the same, and was used under the same conditions as for the modified polyelectrolytes.

(44) With these experiments, surprisingly, it was possible to show that an activating coat whose activating substances are similarly charged to the substances of the aqueous composition for forming the secondary coat, for precipitating, for salting out and/or for depositing, and also for forming a secondary coat, is virtually identical to that in the case of an activating coat which is oppositely charged relative to the substances of the aqueous composition for forming the secondary coat and relative to precipitations and for forming a secondary coat. In this case, however, it has been refrained from forming a dry film in the case of the secondary coat, and so it was not possible to measure any dry film thicknesses.

(45) Nevertheless it was possible to show in principle, with these initial experiments, that an activating coat may also serve successfully for similarly charged substances of the aqueous composition for forming the secondary coat. The precipitation experiments indicate that sufficient dry film thicknesses of the secondary coat can be generated, with, preferably, substances having chemical affinity being selected in each case and being combined in the method of the invention.

(46) TABLE-US-00011 TABLE 11 for cationic-cationic treatment with examples B48 to B52: Cationic activating agent with cationically stabilized dispersion Example B48 B49 B50 B51 B52 Cationic activating agent Type No. 1 2 13 15 16 Cationically stabilized dispersion Type No. (conc. %) 21 (20) 21 (20) 21 (20) 21 (20) 21 (20) Precipitation intensity Strong X X X Weak X Almost no precipitation X

(47) TABLE-US-00012 TABLE 12 for anionic-anionic treatment with examples B53 to B58: Anionic activating agent with anionically stabilized dispersion Example B53 B54 B55 B56 B57 B58 Anionic activating agent Type No. 21 22 25 26 28 30 Anionically stabilized dispersion Type No. 1 (20) 1 (20) 1 (20) 1 (20) 1 (20) 1 (20) (conc. %) Precipitation intensity Strong X X Weak X X Almost no X X precipitation Strong: Activating agent precipitates 61-100% of the dispersion. Weak: Activating agent precipitates 11-60% of the dispersion. Almost no precipitation: Activating agent precipitates 0-10 percent of the dispersion. The values were determined in each case gravimetrically.