EP0155742B1 - Process and coating composition for metallic surface treatment - Google Patents
Process and coating composition for metallic surface treatment Download PDFInfo
- Publication number
- EP0155742B1 EP0155742B1 EP85200412A EP85200412A EP0155742B1 EP 0155742 B1 EP0155742 B1 EP 0155742B1 EP 85200412 A EP85200412 A EP 85200412A EP 85200412 A EP85200412 A EP 85200412A EP 0155742 B1 EP0155742 B1 EP 0155742B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- chromium
- weight
- coating composition
- coating agent
- treatment
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 238000000034 method Methods 0.000 title claims description 25
- 239000008199 coating composition Substances 0.000 title claims description 10
- 238000004381 surface treatment Methods 0.000 title 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 35
- 229910052751 metal Inorganic materials 0.000 claims description 29
- 239000002184 metal Substances 0.000 claims description 29
- 239000011651 chromium Substances 0.000 claims description 26
- 229910019142 PO4 Inorganic materials 0.000 claims description 17
- 239000000377 silicon dioxide Substances 0.000 claims description 16
- 235000012239 silicon dioxide Nutrition 0.000 claims description 15
- 229910052681 coesite Inorganic materials 0.000 claims description 9
- 229910052906 cristobalite Inorganic materials 0.000 claims description 9
- 229910052682 stishovite Inorganic materials 0.000 claims description 9
- 229910052905 tridymite Inorganic materials 0.000 claims description 9
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 claims description 7
- 239000010452 phosphate Substances 0.000 claims description 7
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 claims description 7
- JOPOVCBBYLSVDA-UHFFFAOYSA-N chromium(6+) Chemical compound [Cr+6] JOPOVCBBYLSVDA-UHFFFAOYSA-N 0.000 claims description 6
- 239000010960 cold rolled steel Substances 0.000 claims description 5
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 claims description 4
- 230000002378 acidificating effect Effects 0.000 claims description 2
- BFGKITSFLPAWGI-UHFFFAOYSA-N chromium(3+) Chemical compound [Cr+3] BFGKITSFLPAWGI-UHFFFAOYSA-N 0.000 claims 2
- 239000011248 coating agent Substances 0.000 description 32
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 19
- 229910052804 chromium Inorganic materials 0.000 description 19
- 238000005260 corrosion Methods 0.000 description 12
- 239000003973 paint Substances 0.000 description 12
- 230000007797 corrosion Effects 0.000 description 11
- 238000001035 drying Methods 0.000 description 11
- 239000010410 layer Substances 0.000 description 11
- 238000000576 coating method Methods 0.000 description 7
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 6
- 150000001875 compounds Chemical class 0.000 description 5
- 150000002739 metals Chemical class 0.000 description 5
- 150000003839 salts Chemical class 0.000 description 5
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 4
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 4
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 4
- -1 alkali metal salt Chemical class 0.000 description 4
- 229920000728 polyester Polymers 0.000 description 4
- 239000002966 varnish Substances 0.000 description 4
- 239000011701 zinc Substances 0.000 description 4
- 229910052725 zinc Inorganic materials 0.000 description 4
- ZCDOYSPFYFSLEW-UHFFFAOYSA-N chromate(2-) Chemical compound [O-][Cr]([O-])(=O)=O ZCDOYSPFYFSLEW-UHFFFAOYSA-N 0.000 description 3
- KRVSOGSZCMJSLX-UHFFFAOYSA-L chromic acid Substances O[Cr](O)(=O)=O KRVSOGSZCMJSLX-UHFFFAOYSA-L 0.000 description 3
- 239000006185 dispersion Substances 0.000 description 3
- AWJWCTOOIBYHON-UHFFFAOYSA-N furo[3,4-b]pyrazine-5,7-dione Chemical compound C1=CN=C2C(=O)OC(=O)C2=N1 AWJWCTOOIBYHON-UHFFFAOYSA-N 0.000 description 3
- 230000001771 impaired effect Effects 0.000 description 3
- 229910052742 iron Inorganic materials 0.000 description 3
- 239000007921 spray Substances 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 description 2
- 239000004593 Epoxy Substances 0.000 description 2
- OFOBLEOULBTSOW-UHFFFAOYSA-N Malonic acid Chemical compound OC(=O)CC(O)=O OFOBLEOULBTSOW-UHFFFAOYSA-N 0.000 description 2
- 229920002472 Starch Polymers 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 2
- 239000010941 cobalt Substances 0.000 description 2
- 229910017052 cobalt Inorganic materials 0.000 description 2
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 2
- 239000000470 constituent Substances 0.000 description 2
- 239000003995 emulsifying agent Substances 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 239000004922 lacquer Substances 0.000 description 2
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- 150000004760 silicates Chemical class 0.000 description 2
- 239000002356 single layer Substances 0.000 description 2
- 235000019698 starch Nutrition 0.000 description 2
- 239000008107 starch Substances 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 229910002012 Aerosil® Inorganic materials 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 229910001335 Galvanized steel Inorganic materials 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- 239000005909 Kieselgur Substances 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 239000000443 aerosol Substances 0.000 description 1
- 229910052783 alkali metal Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 150000001768 cations Chemical class 0.000 description 1
- 238000001246 colloidal dispersion Methods 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- GUJOJGAPFQRJSV-UHFFFAOYSA-N dialuminum;dioxosilane;oxygen(2-);hydrate Chemical compound O.[O-2].[O-2].[O-2].[Al+3].[Al+3].O=[Si]=O.O=[Si]=O.O=[Si]=O.O=[Si]=O GUJOJGAPFQRJSV-UHFFFAOYSA-N 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000008397 galvanized steel Substances 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 229910052901 montmorillonite Inorganic materials 0.000 description 1
- 238000010979 pH adjustment Methods 0.000 description 1
- 238000010422 painting Methods 0.000 description 1
- 239000000049 pigment Substances 0.000 description 1
- 229920001296 polysiloxane Polymers 0.000 description 1
- 235000019353 potassium silicate Nutrition 0.000 description 1
- 239000012255 powdered metal Substances 0.000 description 1
- 239000011253 protective coating Substances 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- 239000008237 rinsing water Substances 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 235000019351 sodium silicates Nutrition 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 239000013589 supplement Substances 0.000 description 1
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 1
- 229920002554 vinyl polymer Polymers 0.000 description 1
- 239000002351 wastewater Substances 0.000 description 1
- MFXMOUUKFMDYLM-UHFFFAOYSA-L zinc;dihydrogen phosphate Chemical compound [Zn+2].OP(O)([O-])=O.OP(O)([O-])=O MFXMOUUKFMDYLM-UHFFFAOYSA-L 0.000 description 1
- KHADWTWCQJVOQO-UHFFFAOYSA-N zinc;oxido-(oxido(dioxo)chromio)oxy-dioxochromium Chemical compound [Zn+2].[O-][Cr](=O)(=O)O[Cr]([O-])(=O)=O KHADWTWCQJVOQO-UHFFFAOYSA-N 0.000 description 1
Classifications
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
- C23C22/06—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
- C23C22/24—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing hexavalent chromium compounds
- C23C22/33—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing hexavalent chromium compounds containing also phosphates
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C22/73—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals characterised by the process
- C23C22/74—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals characterised by the process for obtaining burned-in conversion coatings
Definitions
- the invention relates to a process for the treatment of metal surfaces by applying chromium-VI, silicate and / or silicic acid, phosphate and chromium-III-containing aqueous acidic coating agents and subsequent drying of the coating agent, its use for the treatment of cold-rolled steel and for the implementation of Appropriate coating agents.
- a chromate-containing coating agent is known from Patent Abstracts Japan, Volume 8, No. 11 (G-205) [1448], 18-01-1984 and JP-A-58-177 475, which contains 10 to 200 g / l Chromium-VI , 30 to 70 wt .-% chromium-III and silicon dioxide, phosphoric acid and / or malonic acid contains.
- An anti-corrosion film is formed on a metallic plate by treatment with a solution such that the dry film contains 20 to 100 mg / m2 of chromium.
- a primer varnish is then applied and baked in a thickness of 5 to 20 ⁇ m.
- a top coat with a film thickness of 5 to 30 ⁇ m is applied and also baked.
- the object of the invention is to provide a method and coating agent for the treatment of metal surfaces which does not have the disadvantages of the known methods, is simple to carry out and leads to high-quality, in particular corrosion-protective coatings with outstanding resistance to moisture.
- the object is achieved by designing the method of the type mentioned at the outset in accordance with the invention in such a way that a coating agent is applied in which the chromium-VI: SiO2: PO4: chromium total weight ratio is in the range from (0.6 to 0.95 ): (0.5 to 5.0): (0.1 to 5.0): 1 is preferred in which the weight ratio of chromium VI: SiO2: PO4: chromium is in the total range from (0.75 to 0.95): (1 to 3): (0.1 to 1.0): 1.
- the phosphate and chromate component can be introduced into the coating agent intended for carrying out the method according to the invention in any form, provided that the quality of the adhesion-promoting coating is not impaired thereby.
- the addition as an alkali metal salt should be kept as low as possible and avoided as far as possible, since this can result in a loss of quality.
- Phosphate and chromium VI are preferably introduced as comparatively readily soluble salts of di- or trivalent metals or of thermally stable ammonium or amine compounds (including the double salts with the aforementioned metals) or as an acid. Suitable divalent or trivalent metals are, for example, zinc, manganese, chromium, nickel, cobalt and iron.
- the chromate component is preferably added as zinc dichromate or chromic acid and the phosphate component as zinc dihydrogen phosphate.
- the silicate or the silica should be soluble in the coating agent or - homogeneously dispersible to form a colloidal dispersion. It is therefore preferably used in a finely divided form. Aerosols or precipitated silica are particularly suitable, but naturally occurring and finely ground quartz or diatomaceous earth can also be used, provided that they can be dispersed homogeneously. Silicates such as montmorillonite or synthetic fluorosilicates such as e.g. Magnesium fluorosilicate with the trade name Laponit can be used. The use of soluble sodium or potassium silicates or fluorosilicates is less preferred, since these compounds tend to form glassy coatings with low adhesion. Therefore, preference is given to using water-insoluble silica or silicates that are colloidally distributable.
- the chromium III content can be reduced by partial reduction aqueous chromic acid, for example with starch under heating, are produced in the customary manner (for example according to US Pat. No. 3,706,603), the resulting solution then containing chromium-VI and chromium-III compounds.
- the coating agent used in the process according to the invention can also contain further additives. This is e.g. around divalent or trivalent metal cations, such as zinc, manganese, cobalt, nickel or iron, inert color pigments, in order to give the coating a specific color, silicone compounds, conductivity-producing materials, such as powdered metal (see, for example, US Pat. No. 3,671,331) or conductive carbon to increase weldability, and emulsifiers to keep the resin component in the dispersed state.
- the emulsifier is usually already contained in the commercially available aqueous resin dispersion.
- the coating agent can be used without pH adjustment. If the ingredients as salt are divalent or trivalent. Metals or added as acids, the pH will normally be below 2.5. When adding the components in the form of the ammonium or amine salts, the pH should be higher.
- the coating agent can be produced by introducing the individual components in any order taking into account the weight ratios to be set.
- the silica or the silicate is preferably added after the partial reduction of the hexavalent chromium if the reduction is carried out with heating, since otherwise the dispersibility of the silica or silicate is impaired.
- the aforementioned recommendation only applies in the event that the chromium III compound is obtained from chromium VI by reduction.
- the components of the film on the metal surface are initially present in the same concentration as in the coating agent itself. Therefore, the concentrations of the active components in the supplement are essentially the same as in the working coating agent. This favors bathroom control and product uniformity.
- the aqueous coating agent can be applied to the metal surface in any manner, as long as care is taken to ensure that the aqueous film has a reasonable and uniform thickness.
- the film thickness can be checked in the simplest manner by rolling or squeezing rolls, the previous method of application being arbitrary and being able to be carried out, for example, electrostatically or by means of spray technology.
- the layer thicknesses produced using the method according to the invention can be selected within wide limits and e.g. are 4.3 g / m2 and higher. Usually the layer weight will be in the range of 54 to 1,076 mg / m2. Typical coating weights are 54 to 162 mg / m2 for aluminum surfaces, 162 to 270 mg / m2 for steel surfaces and 108 to 216 mg / m2 for zinc surfaces.
- the detailed process conditions are usually set depending on the desired layer weight. Depending on the total concentration of the constituents of the coating agent, a film of a certain thickness is applied to the metal surface and then dried. During the drying process, the concentration of the constituents of the coating agent increases and the reaction begins between it and the metal surface.
- the process is particularly favorable can be carried out if a coating agent is applied whose total chromium content is 0.8 to 12% by weight, preferably 0.8 to 8% by weight.
- the coating agent can be applied at ambient temperature.
- coating agents and / or metal surface can be heated.
- the temperature of the metal can be brought to 93 ° C. or higher in the immersion or roll-up treatment, without the treatment bath being impaired. With the spraying technique, even higher metal temperatures can be set.
- the type of drying is not critical as long as the liquid film is not excessively interrupted or torn open, e.g. due to hot air currents or physical contact during drying. However, the type of drying can influence the temperature required for drying. For example, drying takes place at a lower, maximum object temperature if it is carried out in the infrared oven instead of in the conventional oven.
- the furnace temperature should be measured in such a way that a metal temperature (maximum object temperature) of 52 to 163 ° C results.
- Paint, varnish and the like can be applied to the dried layer in a conventional manner. Even though the paints or varnishes used in the individual influence the corrosion resistance and the adhesion differently, it has been shown that with most of the commercially available paints and varnishes tested, the method according to the invention leads to results which are comparable to two- or three-stage conventional methods.
- the method according to the invention is suitable for the treatment of aluminum, zinc, galvanized steel and iron-containing metal surfaces and alloys thereof.
- a preferred application of the method according to the invention is in the treatment of cold-rolled steel, in particular because of the achievable high corrosion resistance and the achievable free formability of the coated and temporarily stored strip or sheet.
- Part of the invention is an aqueous coating agent for the treatment of metal surfaces containing chromium VI, silicate and / or silicic acid, phosphate and chromium III, which is characterized in that it is the total chromium VI: SiO2: PO4: chromium Weight ratio of (0.6 to 0.95): (0.5 to 5.0): (0.1 to 5.0): 1, preferably from (0.75 to 0.95): (1 to 3): (0.1 to 1.0): 1 contains.
- the absolute content of the active components of the coating agent essentially depends on the type of application. In general, the total chromium content is 0.8 to 12% by weight, preferably 0.8 to 8% by weight.
- the advantage of the invention is in particular that coating agent is applied only once without rinsing, yet high corrosion protection - even with low layer weights - and good deformability are achieved as a result of good adhesion of paint or lacquer. A large number of metals can be treated.
- a chromic acid solution is converted into a solution containing chromium VI and chromium III by partial reduction of the chromium VI with starch under the action of heat. Then phosphoric acid and a 10% (w / v) aerosil dispersion (silica ground in water) are added such that a dispersion with a weight ratio of chromium-VI: PO4: SiO2: chromium total like 0.87: 0 , 97: 2.0: 1.0 results.
- the coating agent was applied to cold-rolled steel sheets with corrugated suction rolls, so that after drying in a conventional oven to a maximum temperature of the metal of 82 to 93 ° C., the layer weight was once 0.4 and once 0.183 g / m2. The sheets then rested for two weeks.
- Example 2 After the procedure of Example 1, three coating compositions were prepared which contained the components CrVI, PO4, SiO2 and Cr in total in the following weight ratios.
- Example 2 coatings were applied using the aforementioned coating agents at a maximum object temperature of 82 to 93 ° C. in a conventional oven. Then the pre-treated sheets were painted.
- the coating agent according to Example 3 was applied to the surface of hot-rolled steel sheet which had been preheated to approximately 93 ° C. After about 1 minute, the sheets were provided with a single-layer polyester lacquer or with a two-layer epoxy polyester topcoat. These sheets treated in this way were distinguished by excellent corrosion resistance, excellent paint adhesion and deformability.
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- Chemical & Material Sciences (AREA)
- General Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Chemical Treatment Of Metals (AREA)
- Application Of Or Painting With Fluid Materials (AREA)
- Paints Or Removers (AREA)
Description
Die Erfindung betrifft ein Verfahren zur Behandlung von Metalloberflächen durch Aufbringen von Chrom-VI, Silikat und/oder Kieselsäure, Phosphat und Chrom-III enthaltenden wäßrigen, sauren Überzugsmitteln und anschließendes Auftrocknen des Überzugsmittels, dessen Anwendung zur Behandlung von kaltgewalztem Stahl und für die Durchführung des Verfahrens geeignete Überzugsmittel.The invention relates to a process for the treatment of metal surfaces by applying chromium-VI, silicate and / or silicic acid, phosphate and chromium-III-containing aqueous acidic coating agents and subsequent drying of the coating agent, its use for the treatment of cold-rolled steel and for the implementation of Appropriate coating agents.
Die Notwendigkeit, Überzüge auf Metalloberflächen, insbesondere zur Vorbehandlung vor der nachfolgenden Lackierung, aufzubringen, ist seit langem bekannt. In diesem Zusammenhang wird besondere Beachtung der Lackhaftung auf der Metalloberfläche, der Feuchtigkeitsbeständigkeit der lackierten Metalloberfläche, der Salzsprühbeständigkeit und dem mit weiteren Methoden ermittelten Korrosionsverhalten des lackierten Artikels geschenkt. Sofern eine Verformung der lackierten Oberfläche beabsichtigt ist, ist auch die Verformbarkeit und der Korrosionswiderstand nach der Verformung von Bedeutung.The need to apply coatings to metal surfaces, especially for pretreatment before subsequent painting, has long been known. In this context, special attention is paid to the paint adhesion on the metal surface, the moisture resistance of the painted metal surface, the salt spray resistance and the corrosion behavior of the painted article determined using other methods. If deformation of the painted surface is intended, the deformability and the corrosion resistance after the deformation are also important.
In der Vergangenheit sind häufig Schwierigkeiten bei der Entwicklung von Überzugsmitteln für und Behandlungsverfahren von Metalloberflächen aufgetreten, wenn Produkte gefordert wurden, die bei und nach der Verformung eine zufriedenstellende Lackhaftung und einen zufriedenstellenden Korrosionswiderstand aufweisen sollen. Beispielsweise werden Üblicherweise hohe Schichtgewichte im Hinblick auf Korrosionsschutz, aber niedrige Schichtgewichte für die Verformung gefordert. Im allgemeinen läßt sich feststellen, daß konventionelle Überzugsmittel und Verfahren zur Behandlung von Metalloberflächen mehrstufige Behandlungsverfahren mit Wasserspülung nach jeder Behandlungsstufe erfordern. Dies ist jedoch mit einem hohen Personalaufwand, Kontaminierungsproblemen zwischen den Stufen, einer beträchtlichen Anlagenlänge und Abwasserproblemen für die Spülwässer verbunden.In the past, difficulties have often arisen in the development of coating compositions for and treatment processes of metal surfaces when products have been required which are to have satisfactory paint adhesion and corrosion resistance during and after the deformation. For example, high layer weights are usually required with regard to corrosion protection, but low layer weights are required for the deformation. in the In general, it can be said that conventional coating agents and processes for treating metal surfaces require multi-step treatment processes with water rinsing after each treatment step. However, this is associated with a high level of personnel expenditure, contamination problems between the stages, a considerable length of the plant and waste water problems for the rinsing water.
Aus Patent Abstracts Japan, Band 8, Nr. 11 (G-205) [1448], 18-01-1984 und JP-A-58-177 475 ist ein chromathaltiges Überzugsmittel bekannt, das 10 bis 200 g/l Chrom-VI, 30 bis 70 Gew.-% Chrom-III sowie Siliciumdioxid, Phosphorsäure und/oder Malonsäure enthält. Ein Korrosionsschutzfilm wird auf einer metallischen Platte durch Behandlung mit einer Lösung derart gebildet, daß der trockene Filme 20 bis 100 mg/m² Chrom enthält. Hierauf wird ein Grundierungslack aufgebracht und in einer Dicke von 5 bis 20 µm eingebrannt. Hierauf wird ein Decklack mit einer Filmdicke von 5 bis 30 µm aufgebracht und ebenfalls eingebrannt.A chromate-containing coating agent is known from Patent Abstracts Japan, Volume 8, No. 11 (G-205) [1448], 18-01-1984 and JP-A-58-177 475, which contains 10 to 200 g / l Chromium-VI , 30 to 70 wt .-% chromium-III and silicon dioxide, phosphoric acid and / or malonic acid contains. An anti-corrosion film is formed on a metallic plate by treatment with a solution such that the dry film contains 20 to 100 mg / m² of chromium. A primer varnish is then applied and baked in a thickness of 5 to 20 µm. A top coat with a film thickness of 5 to 30 µm is applied and also baked.
Aufgabe der Erfindung ist es, ein Verfahren und Überzugsmittel zur Behandlung von Metalloberflächen bereitzustellen, das die Nachteile der bekannten Verfahren nicht aufweist, einfach in der Durchführung ist und zu qualitativ hochwertigen, insbesondere korrosionsschützenden Überzügen mit herausragender Widerstandsfähigkeit gegenüber Feuchtigkeit führt.The object of the invention is to provide a method and coating agent for the treatment of metal surfaces which does not have the disadvantages of the known methods, is simple to carry out and leads to high-quality, in particular corrosion-protective coatings with outstanding resistance to moisture.
Die Aufgabe wird gelöst, indem das Verfahren der eingangs genannten Art ensprechend der Erfindung derart ausgestaltet wird, daß man ein Überzugsmittel aufbringt, in dem das Gewichtsverhältnis Chrom-VI : SiO₂ : PO₄ : Chromgesamt im Bereich von (0,6 bis 0,95) : (0,5 bis 5,0) : (0,1 bis 5,0) : 1 liegt vorzugsweise
in dem das Gewichtsverhältnis Chrom-VI : SiO₂ : PO₄ : Chromgesamt im Bereich von (0,75 bis 0,95) : (1 bis 3) : (0,1 bis 1,0) : 1 liegt.The object is achieved by designing the method of the type mentioned at the outset in accordance with the invention in such a way that a coating agent is applied in which the chromium-VI: SiO₂: PO₄: chromium total weight ratio is in the range from (0.6 to 0.95 ): (0.5 to 5.0): (0.1 to 5.0): 1 is preferred
in which the weight ratio of chromium VI: SiO₂: PO₄: chromium is in the total range from (0.75 to 0.95): (1 to 3): (0.1 to 1.0): 1.
Die Phosphat- und Chromatkomponente kann in das zur Durchführung des erfindungsgemäßen Verfahrens bestimmte Überzugsmittel in jeder beliebigen Form eingebracht werden, sofern die Qualität des haftvermittelnden Überzuges hierdurch nicht beeinträchtigt wird. Die Zugabe als Alkalimetallsalz sollte so gering wie möglich gehalten, möglichst ganz vermieden werden, da hierdurch Qualitätseinbußen auftreten können. Phosphat und Chrom-VI werden vorzugsweise als vergleichsweise gut lösliche Salze von zwei- oder dreiwertigen Metallen oder von thermisch stabilen Ammonium- oder Aminverbindungen (einschließlich der Doppelsalze mit den vorgenannten Metallen) oder als Säure eingebracht. Geeignete zwei- oder dreiwertige Metalle sind beispielsweise Zink, Mangan, Chrom, Nickel, Cobalt und Eisen. Die Chromatkomponente wird vorzugsweise als Zinkdichromat oder Chromsäure und die Phosphatkomponente als Zinkdihydrogenphosphat zugegeben.The phosphate and chromate component can be introduced into the coating agent intended for carrying out the method according to the invention in any form, provided that the quality of the adhesion-promoting coating is not impaired thereby. The addition as an alkali metal salt should be kept as low as possible and avoided as far as possible, since this can result in a loss of quality. Phosphate and chromium VI are preferably introduced as comparatively readily soluble salts of di- or trivalent metals or of thermally stable ammonium or amine compounds (including the double salts with the aforementioned metals) or as an acid. Suitable divalent or trivalent metals are, for example, zinc, manganese, chromium, nickel, cobalt and iron. The chromate component is preferably added as zinc dichromate or chromic acid and the phosphate component as zinc dihydrogen phosphate.
Das Silikat oder die Kieselsäure sollte in dem Überzugsmittel löslich oder - unter Bildung einer kolloidalen Dispersion - homogen dispergierbar sein. Es wird daher vorzugsweise in feinverteilter Form verwendet. Besonders geeignet sind Aerosole oder gefällte Kieselsäure, jedoch können auch natürlich vorkommender und fein aufgemahlener Quarz oder Diatomeenerde verwendet werden, sofern sie sich homogen dispergieren lassen. Es können auch Silikate, wie Montmorillonit, oder synthetische Fluorosilikate, wie z.B. Magnesiumfluorosilikat mit der Handelsbezeichnung Laponit, eingesetzt werden. Die Verwendung löslicher Natrium- oder Kaliumsilikate bzw. Fluorosilikate ist weniger bevorzugt, da diese Verbindungen die Neigung besitzen, glasige Überzüge mit geringem Haftvermögen zu bilden. Daher wird der Verwendung wasserunlöslicher Kieselsäure oder Silikate, die kolloidal verteilbar sind, der Vorzug gegeben.The silicate or the silica should be soluble in the coating agent or - homogeneously dispersible to form a colloidal dispersion. It is therefore preferably used in a finely divided form. Aerosols or precipitated silica are particularly suitable, but naturally occurring and finely ground quartz or diatomaceous earth can also be used, provided that they can be dispersed homogeneously. Silicates such as montmorillonite or synthetic fluorosilicates such as e.g. Magnesium fluorosilicate with the trade name Laponit can be used. The use of soluble sodium or potassium silicates or fluorosilicates is less preferred, since these compounds tend to form glassy coatings with low adhesion. Therefore, preference is given to using water-insoluble silica or silicates that are colloidally distributable.
Der Chrom-III-Anteil kann durch partielle Reduktion einer wäßrigen Chromsäure, z.B. mit Stärke unter Erwärmung, auf übliche Weise erzeugt werden (z.B. gemäß US-PS 3 706 603), wobei dann die resultierende Lösung Chrom-VI- und Chrom-III-Verbindungen enthält.The chromium III content can be reduced by partial reduction aqueous chromic acid, for example with starch under heating, are produced in the customary manner (for example according to US Pat. No. 3,706,603), the resulting solution then containing chromium-VI and chromium-III compounds.
Neben den vorgenannten Verbindungen kann das innerhalb des erfindungsgemäßen Verfahrens zum Einsatz kommende Überzugsmittel noch weitere Zusätze erhalten. Hierbei handelt es sich z.B. um zwei- oder dreiwertige Metallkationen, wie Zink, Mangan, Cobalt, Nickel oder Eisen, inerte Farbpigmente, um dem Überzug eine spezifische Farbe zu geben, Silikonverbindungen, Leitfähigkeit herbeiführende Materialien, wie pulverförmiges Metall (vgl. z.B. US-PS 3 671 331) oder leitfähiger Kohlenstoff, um die Schweißbarkeit zu erhöhen, sowie Emulgatoren, die die Harzkomponente im dispergierten Zustand halten. Der Emulgator ist üblicherweise in der handelsüblichen wäßrigen Harzdispersion bereits enthalten.In addition to the aforementioned compounds, the coating agent used in the process according to the invention can also contain further additives. This is e.g. around divalent or trivalent metal cations, such as zinc, manganese, cobalt, nickel or iron, inert color pigments, in order to give the coating a specific color, silicone compounds, conductivity-producing materials, such as powdered metal (see, for example, US Pat. No. 3,671,331) or conductive carbon to increase weldability, and emulsifiers to keep the resin component in the dispersed state. The emulsifier is usually already contained in the commercially available aqueous resin dispersion.
Das Überzugsmittel kann ohne pH-Wert-Einstellung benutzt werden. Wenn die Bestandteile als Salz zwei- oder dreiwertiger . Metalle oder als Säuren zugegeben werden, wird der pH-Wert normalerweise unter 2,5 liegen. Bei Zugabe der Bestandteile in Form der Ammonium- oder Aminsalze dürfte der pH-Wert höher sein.The coating agent can be used without pH adjustment. If the ingredients as salt are divalent or trivalent. Metals or added as acids, the pH will normally be below 2.5. When adding the components in the form of the ammonium or amine salts, the pH should be higher.
Das Überzugsmittel kann hergestellt werden, indem die einzelnen Bestandteile unter Berücksichtigung der einzustellenden Gewichtsverhältnisse in beliebiger Reihenfolge eingebracht werden. Jedoch wird die Kieselsäure oder das Silikat vorzugsweise nach der partiellen Reduktion des sechswertigen Chroms zugegeben, sofern die Reduktion unter Erwärmung durchgeführt wird, da andernfalls die Dispergierbarkeit von Kieselsäure oder Silikat verschlechtert wird. Die vorgenannte Empfehlung gilt jedoch nur für den Fall, daß die Chrom-III-Verbindung aus Chrom-VI durch Reduktion gewonnen wird.The coating agent can be produced by introducing the individual components in any order taking into account the weight ratios to be set. However, the silica or the silicate is preferably added after the partial reduction of the hexavalent chromium if the reduction is carried out with heating, since otherwise the dispersibility of the silica or silicate is impaired. However, the aforementioned recommendation only applies in the event that the chromium III compound is obtained from chromium VI by reduction.
Da keine wesentliche Reaktion mit der Metalloberfläche vor dem Auftrocknen stattfindet, sind die Komponenten des auf der Metalloberfläche befindlichen Films anfänglich in der gleichen Konzentration vorhanden wie im Überzugsmittel selbst. Daher sind die Konzentrationen der wirksamen Komponenten im Ergänzungsmittel im wesentlichen die gleichen wie im arbeitenden Überzugsmittel. Hierdurch werden Badkontrolle und Produktgleichmäßigkeit begünstigt.Since there is no substantial reaction with the metal surface prior to drying, the components of the film on the metal surface are initially present in the same concentration as in the coating agent itself. Therefore, the concentrations of the active components in the supplement are essentially the same as in the working coating agent. This favors bathroom control and product uniformity.
Die Aufbringung des wäßrigen Überzugsmittels auf die Metalloberfläche kann auf jede beliebige Art erfolgen, solange Sorge dafür getragen wird, daß eine sinnvolle und einheitliche Dicke des wäßrigen Films entsteht. Für ebene Flächen, wie Band oder Blech, kann die Filmdicke in einfachster Weise durch Rollen oder Abquetschrollen kontrolliert werden, wobei die vorherige Art der Aufbringung beliebig ist und beispielsweise elektrostatisch oder mittels Sprühtechnik erfolgen kann.The aqueous coating agent can be applied to the metal surface in any manner, as long as care is taken to ensure that the aqueous film has a reasonable and uniform thickness. For flat surfaces such as strip or sheet metal, the film thickness can be checked in the simplest manner by rolling or squeezing rolls, the previous method of application being arbitrary and being able to be carried out, for example, electrostatically or by means of spray technology.
Die mit Hilfe des erfindungsgemäßen Verfahrens erzeugten Schichtdicken können in weiten Grenzen gewählt werden und z.B. bei 4,3 g/m² und höher liegen. Normalerweise wird das Schichtgewicht im Bereich von 54 bis 1.076 mg/m² liegen. Typische Schichtgewichte sind für Aluminiumoberflächen 54 bis 162 mg/m², für Stahloberflächen 162 bis 270 mg/m² und für Zinkoberflächen 108 bis 216 mg/m².The layer thicknesses produced using the method according to the invention can be selected within wide limits and e.g. are 4.3 g / m² and higher. Usually the layer weight will be in the range of 54 to 1,076 mg / m². Typical coating weights are 54 to 162 mg / m² for aluminum surfaces, 162 to 270 mg / m² for steel surfaces and 108 to 216 mg / m² for zinc surfaces.
Üblicherweise werden die detaillierte Prozeßbedingungen in Abhängigkeit vom gewünschten Schichtgewicht eingestellt. Je nach Gesamtkonzentration der Bestandteile des Überzugsmittels wird ein Film bestimmter Dicke auf die Metalloberfläche aufgebracht und dann aufgetrocknet. Während des Auftrocknens steigt die Konzentration der Bestandteile des Überzugsmittels und zwischen ihm und der Metalloberfläche beginnt die Reaktion.The detailed process conditions are usually set depending on the desired layer weight. Depending on the total concentration of the constituents of the coating agent, a film of a certain thickness is applied to the metal surface and then dried. During the drying process, the concentration of the constituents of the coating agent increases and the reaction begins between it and the metal surface.
Es hat sich gezeigt, daß das Verfahren besonders günstig durchführbar ist, wenn man ein Überzugsmittel aufbringt, dessen Gehalt an Chromgesamt 0,8 bis 12 Gew.-%, vorzugsweise 0,8 bis 8 Gew.-%, beträgt.It has been shown that the process is particularly favorable can be carried out if a coating agent is applied whose total chromium content is 0.8 to 12% by weight, preferably 0.8 to 8% by weight.
Das Überzugsmittel kann mit Umgebungstemperatur aufgebracht werden. Um den Prozeß zu beschleunigen, können jedoch Überzugsmittel und/oder Metalloberfläche erwärmt werden. Beispielsweise kann bei der Tauch- oder Aufrollbehandlung die Temperatur des Metalles auf 93°C oder höher gebracht werden, ohne daß das Behandlungsbad beeinträchtigt wird. Bei der Aufsprühtechnik können noch höhere Metalltemperaturen eingestellt werden. Die Art der Auftrocknung ist solange nicht kritisch, wie der Flüssigkeitsfilm nicht übermäßig unterbrochen oder aufgerissen wird, z.B. durch heiße Luftströme oder physikalischen Kontakt bei der Trocknung. Jedoch kann die Art der Auftrocknung die für die Auftrocknung erforderliche Temperatur beeinflussen. Beispielsweise wird die Auftrocknung bei niedrigerer, maximaler Objekttemperatur erreicht, wenn sie im Infrarotofen anstatt im konventionellen Ofen erfolgt.The coating agent can be applied at ambient temperature. To accelerate the process, however, coating agents and / or metal surface can be heated. For example, the temperature of the metal can be brought to 93 ° C. or higher in the immersion or roll-up treatment, without the treatment bath being impaired. With the spraying technique, even higher metal temperatures can be set. The type of drying is not critical as long as the liquid film is not excessively interrupted or torn open, e.g. due to hot air currents or physical contact during drying. However, the type of drying can influence the temperature required for drying. For example, drying takes place at a lower, maximum object temperature if it is carried out in the infrared oven instead of in the conventional oven.
Unter normalen Bedingungen ist die Verwendung von erhöhten Ofentemperaturen und Warmluftströmen einer Geschwindigkeit, die den Naßfilm nicht nachteilig beeinträchtigen, bevorzugt. Aus praktischer Sicht sollte die Ofentemperatur derart bemessen werden, daß eine Metalltemperatur (maximale Objekttemperatur) von 52 bis 163°C resultiert.Under normal conditions, the use of elevated oven temperatures and hot air streams at a speed that does not adversely affect the wet film is preferred. From a practical point of view, the furnace temperature should be measured in such a way that a metal temperature (maximum object temperature) of 52 to 163 ° C results.
Auf die aufgetrocknete Schicht kann Farbe, Lack und dergl. auf übliche Weise aufgebracht werden. Wenn auch die im einzelnen verwendeten Farben oder Lacke den Korrosionswiderstand und die Haftung unterschiedlich beeinflussen, so hat sich doch gezeigt, daß bei den meisten getesteten handelsüblichen Farben und Lacken das erfindungsgemäße Verfahren zu Ergebnissen führt, die mit zwei- oder dreistufigen konventionellen Verfahren vergleichbar sind.Paint, varnish and the like can be applied to the dried layer in a conventional manner. Even though the paints or varnishes used in the individual influence the corrosion resistance and the adhesion differently, it has been shown that with most of the commercially available paints and varnishes tested, the method according to the invention leads to results which are comparable to two- or three-stage conventional methods.
Das erfindungsgemäße Verfahren ist zur Behandlung von Aluminium, Zink, verzinktem Stahl und eisenhaltigen Metalloberflächen und Legierungen hiervon geeignet. Ein bevorzugter Anwendungsfall des erfindungsgemäßen Verfahrens liegt in der Behandlung von kaltgewalztem Stahl, und zwar insbesondere wegen des erzielbaren hohen Korrosionswiderstandes und der erzielbaren einwardfreien Verformbarkeit von lackiertem und zwischengelagertem Band oder Blech.The method according to the invention is suitable for the treatment of aluminum, zinc, galvanized steel and iron-containing metal surfaces and alloys thereof. A preferred application of the method according to the invention is in the treatment of cold-rolled steel, in particular because of the achievable high corrosion resistance and the achievable free formability of the coated and temporarily stored strip or sheet.
Bestandteil der Erfindung ist ein wäßriges Überzugsmittel zur Behandlung von Metalloberflächen mit einen Gehalt an Chrom-VI, Silikat und/oder Kieselsäure, Phospat und Chrom-III, das dadurch gekennzeichnet ist, daß es das Chrom-VI : SiO₂ : PO₄ : Chromgesamt im Gewichtsverhältnis von (0,6 bis 0,95) : (0,5 bis 5,0) : (0,1 bis 5,0) : 1, vorzugsweise
von (0,75 bis 0,95) : (1 bis 3) : (0,1 bis 1,0) : 1 enthält.Part of the invention is an aqueous coating agent for the treatment of metal surfaces containing chromium VI, silicate and / or silicic acid, phosphate and chromium III, which is characterized in that it is the total chromium VI: SiO₂: PO₄: chromium Weight ratio of (0.6 to 0.95): (0.5 to 5.0): (0.1 to 5.0): 1, preferably
from (0.75 to 0.95): (1 to 3): (0.1 to 1.0): 1 contains.
Der Absolutgehalt der wirksamen Bestandteile des Überzugsmittels hängt im wesentlichen von der Art der Aufbringung ab. Im allgemeinen liegt der Gehalt an Chromgesamt bei 0,8 bis 12 Gew.-%, vorzugsweise bei 0,8 bis 8 Gew.-%.The absolute content of the active components of the coating agent essentially depends on the type of application. In general, the total chromium content is 0.8 to 12% by weight, preferably 0.8 to 8% by weight.
Der Vorteil der Erfindung besteht insbesondere darin, daß nur ein einmaliger Auftrag von Überzugsmittel ohne Nachspülung erfolgt, dennoch hoher Korrosionsschutz - selbst bei geringen Schichtgewichten - und gute Verformbarkeit infolge guter Haftung von Farbe oder Lack erreicht werden. Es kann eine große Zahl von Metallen behandelt werden.The advantage of the invention is in particular that coating agent is applied only once without rinsing, yet high corrosion protection - even with low layer weights - and good deformability are achieved as a result of good adhesion of paint or lacquer. A large number of metals can be treated.
Die Erfindung wird anhand der Beispiele beispielsweise und näher beschrieben.The invention is described by way of example and in more detail.
Zur Herstellung eines Überzugsmittels wird eine Chromsäurelösung durch partielle Reduktion des Chrom-VI mit Stärke unter Wärmeeinwirkung in eine Chrom-VI und Chrom-III enthaltende Lösung überführt. Dann wird mit Phosphorsäure und einer 10%igen (Gew.-/Vol.) Aerosildispersion (in Wasser aufgemahlene Kieselsäure) derart versetzt, daß eine Dispersion mit einem Gewichtsverhältnis von Chrom-VI : PO₄ : SiO₂ : Chromgesamt wie 0,87 : 0,97 : 2,0 : 1,0 resultiert.To produce a coating agent, a chromic acid solution is converted into a solution containing chromium VI and chromium III by partial reduction of the chromium VI with starch under the action of heat. Then phosphoric acid and a 10% (w / v) aerosil dispersion (silica ground in water) are added such that a dispersion with a weight ratio of chromium-VI: PO₄: SiO₂: chromium total like 0.87: 0 , 97: 2.0: 1.0 results.
Das Überzugsmittel wurde auf kaltgewalzte Stahlbleche mit geriffelten Abguetschwalzen aufgetragen, so daß sich nach Trocknung in einem konventionellen Ofen auf eine Maximaltemperatur des Metalles auf 82 bis 93°C ein Schichtgewicht von einmal 0,4 und einmal 0,183 g/m² ergab. Danach ruhten die Bleche zwei Wochen.The coating agent was applied to cold-rolled steel sheets with corrugated suction rolls, so that after drying in a conventional oven to a maximum temperature of the metal of 82 to 93 ° C., the layer weight was once 0.4 and once 0.183 g / m². The sheets then rested for two weeks.
Dann wurden einige der Bleche mit einem Einschicht-Polyesterlack, einige mit einem Einschicht-Vinyllack und einige mit einem Zweischicht-Epoxypolyesterlack versehen. Alle Bleche zeigten gute Lackhaftung, gute Korrosionsbeständigkeit und gute Verformbarkeit.Then some of the sheets were coated with a one-layer polyester paint, some with a single-layer vinyl paint and some with a two-layer epoxy polyester paint. All sheets showed good paint adhesion, good corrosion resistance and good ductility.
Nach dem Verfahrensgang des Beispiels 1 wurden drei Überzugsmittel hergestellt, die die Komponenten CrVI, PO₄, SiO₂ und Crgesamt in folgenden Gewichtsverhältnissen enthielt.
Wie in Beispiel 1 wurden mittels der vorgenannten Überzugsmittel Überzüge bei einer maximalen Objekttemperatur von 82 bis 93°C in einem konventionellen Ofen aufgebracht. Dann wurden die so vorbehandelten Bleche lackiert.As in Example 1, coatings were applied using the aforementioned coating agents at a maximum object temperature of 82 to 93 ° C. in a conventional oven. Then the pre-treated sheets were painted.
Ein Vergleich der behandelten Bleche zeigte, daß sich der Korrosionsschutz (ermittelt im Salzsprühtest) mit steigendem PO₄-Gehalt verbesserte, jedoch die Verformbarkeit verringerte.A comparison of the treated sheets showed that the corrosion protection (determined in the salt spray test) improved with increasing PO₄ content, but reduced the deformability.
Auf kaltgewalzten Stahl wurde mit einem Überzugsmittel, in dem das Gewichtsverhältnis CrVI : PO₄ : SiO₂ : Crgesamt 0,93 : 0,32 : 2,0 : 1,0 war, nach dem Rollenauftragsverfahren ein Überzug mit 0,215 g/m² (nach der Auftrocknung aufgebracht.On cold-rolled steel with a coating agent in which the weight ratio CrVI: PO₄: SiO₂: Cr was 0.93: 0.32: 2.0: 1.0 in total , a coating with 0.215 g / m² (according to the Drying applied.
Die Auftrocknung erfolgte bei einer maximalen Objekttemperatur von 149°C. Nach 30 sec langem Abkühlen im Raum wurden die Bleche, wie in Beispiel 1 angegeben, lackiert. Alle Bleche besaßen guten Korrosionswiderstand, gute Lackhaftungseigenschaften und gute Verformbarkeit.Drying was carried out at a maximum object temperature of 149 ° C. After cooling for 30 seconds in the room, the metal sheets were painted as described in Example 1. All sheets had good corrosion resistance, good paint adhesion properties and good ductility.
Das Überzugsmittel gemäß Beispiel 3 wurde auf die Oberfläche von heißgewalztem Stahlblech, das auf ca. 93°C vorgewärmt worden war, aufgetragen. Nach etwa 1 min wurden die Bleche mit einem Einschicht-Polyesterlack bzw. mit einem Zweischicht-Epoxypolyesterabdecklack versehen. Diese so behandelten Bleche zeichneten sich durch hervorragenden Korrosionswiderstand, hervorragende Lackhaftung und Verformbarkeit aus.The coating agent according to Example 3 was applied to the surface of hot-rolled steel sheet which had been preheated to approximately 93 ° C. After about 1 minute, the sheets were provided with a single-layer polyester lacquer or with a two-layer epoxy polyester topcoat. These sheets treated in this way were distinguished by excellent corrosion resistance, excellent paint adhesion and deformability.
Claims (6)
- A process for the treatment of metal surfaces by applying thereonto aqueous acidic coating compositions containing chromium(VI), silicate and/or silicic acid, phosphate and chromium(III) followed by drying-up the coating composition, characterized in that a coating composition is applied wherein the ratio by weight of chromium(VI) : SiO₂ : PO₄ : chromiumtotal is within the range of from (0.6 to 0.95) : (0.5 to 5.0) : (0.1 to 5.0) : 1.
- The process according to claim 1, characterized in that a coating composition is applied wherein the ratio by weight of chromium(VI) : SiO₂ : PO₄ : chromiumtotal is within the range of from (0.75 to 0.95) : (1 to 3) : (0.1 to 1.0) : 1.
- The process according to claims 1 or 2, characterized in that a coating composition is applied, the chromiumtotal content of which is from 0.8 to l2, and preferably from 0.8 to 8 % by weight.
- Application of the process according to one or several of claims 1 to 3 to the treatment of cold-rolled steel.
- An aqueous coating composition for the treatment of metal surfaces which contains chromium(VI), silicate and/or silicic acid, phosphate and chromium(III), characterized in that it contains chromium(VI) : SiO₂ : PO₄ : chromiumtotal in a ratio by weight of from (0.6 to 0.95) : (0.5 to 5.0) : (0.1 to 5.0) : 1, and preferably in a ratio by weight of from (0.75 to 0.95) : (1 to 3) : (0.1 to 1.0) : 1.
- The coating composition according to claim 5, characterized in that it contains from 0.8 to 12% by weight, and preferably from 0.8 to 8% by weight, of chromiumtotal.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US59259184A | 1984-03-23 | 1984-03-23 | |
| US592591 | 2000-06-12 |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| EP0155742A2 EP0155742A2 (en) | 1985-09-25 |
| EP0155742A3 EP0155742A3 (en) | 1987-04-29 |
| EP0155742B1 true EP0155742B1 (en) | 1991-07-24 |
Family
ID=24371303
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP85200412A Expired - Lifetime EP0155742B1 (en) | 1984-03-23 | 1985-03-19 | Process and coating composition for metallic surface treatment |
Country Status (11)
| Country | Link |
|---|---|
| EP (1) | EP0155742B1 (en) |
| JP (1) | JPS60218483A (en) |
| AR (1) | AR242247A1 (en) |
| AU (1) | AU580041B2 (en) |
| BR (1) | BR8501308A (en) |
| CA (1) | CA1256003A (en) |
| DE (2) | DE3509556A1 (en) |
| GB (1) | GB2155962B (en) |
| MX (1) | MX166776B (en) |
| NZ (1) | NZ211485A (en) |
| ZA (1) | ZA852128B (en) |
Families Citing this family (20)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0222282A3 (en) * | 1985-11-04 | 1987-08-19 | HENKEL CORPORATION (a Delaware corp.) | Process for coating metal surfaces with organic layers |
| JPH07116615B2 (en) * | 1986-05-20 | 1995-12-13 | 日本パ−カライジング株式会社 | Chromate treatment liquid and method for zinc or zinc alloy plated steel sheet, cold rolled steel sheet and stainless steel sheet |
| JPS6313741A (en) * | 1986-07-04 | 1988-01-21 | 大同鋼板株式会社 | Coated titanium plate |
| JPS6313740A (en) * | 1986-07-04 | 1988-01-21 | 大同鋼板株式会社 | Coated steel plate |
| US4881975A (en) * | 1986-12-23 | 1989-11-21 | Albright & Wilson Limited | Products for treating surfaces |
| GB2201157B (en) * | 1986-12-23 | 1991-07-17 | Albright & Wilson | Processes and products for surface treatment |
| JPS63171685A (en) * | 1986-12-30 | 1988-07-15 | Nippon Steel Corp | Formation of anticorrosive white chromate film |
| EP0305560B1 (en) * | 1987-08-31 | 1991-06-26 | Nippon Paint Co., Ltd. | Metal particle |
| JPH0637706B2 (en) * | 1987-09-04 | 1994-05-18 | 日新製鋼株式会社 | High corrosion resistance chromate treatment method for galvanized steel sheet |
| EP0310103A1 (en) * | 1987-10-01 | 1989-04-05 | HENKEL CORPORATION (a Delaware corp.) | Pretreatment process for aluminium |
| JPH01123673A (en) * | 1987-11-06 | 1989-05-16 | Nippon Parkerizing Co Ltd | Moldproof bacterial hydrophilic surface treatment of aluminum |
| JPH01240673A (en) * | 1988-03-22 | 1989-09-26 | Nippon Steel Corp | Manufacture of gold-colored chromate-treated galvanized sheet steel having excellent corrosion resistance |
| JPH03146676A (en) * | 1989-10-31 | 1991-06-21 | Kobe Steel Ltd | Production of chromated steel sheet having superior resistance to stain by moisture absorption |
| JPH0696778B2 (en) * | 1990-10-05 | 1994-11-30 | 新日本製鐵株式会社 | Chromate treatment method for galvanized steel sheet |
| JPH04193957A (en) * | 1990-11-28 | 1992-07-14 | Nippon Parkerizing Co Ltd | Chromating solution for substrate for clear coat |
| JP2668474B2 (en) * | 1991-10-29 | 1997-10-27 | 黒野 朔 | Aluminum surface protection coating |
| JPH0693464A (en) * | 1992-09-10 | 1994-04-05 | Nippon Steel Corp | Primary coating chromate composition for precoated steel sheet and treatment therefor |
| JPH0693466A (en) * | 1992-09-10 | 1994-04-05 | Nippon Steel Corp | Primary coating chromate composition for precoated steel sheet and treatment therefor |
| JPH06108265A (en) * | 1992-09-29 | 1994-04-19 | Nippon Steel Corp | Chromate treatment for primer coating of coated steel sheet |
| DE102015104887B4 (en) | 2015-03-30 | 2022-05-19 | Benteler Steel/Tube Gmbh | Tubular product and method of making same |
Family Cites Families (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2529206A (en) * | 1948-02-18 | 1950-11-07 | Gen Electric | Process for increasing the corrosion resistance of ferrous articles |
| DE1249965B (en) * | 1964-08-12 | |||
| DE1769582C3 (en) * | 1967-06-14 | 1979-12-13 | British Chrome & Chemicals Ltd., Stockton-On-Tees (Grossbritannien) | Surface treatment agents for metals, processes for their production and their use for producing corrosion-resistant and electrically resistant coatings |
| US3798074A (en) * | 1972-03-23 | 1974-03-19 | Allegheny Ludlum Ind Inc | Surface finishing |
| US4032366A (en) * | 1975-05-23 | 1977-06-28 | Allegheny Ludlum Industries, Inc. | Grain-oriented silicon steel and processing therefor |
| JPS5917521B2 (en) * | 1975-08-22 | 1984-04-21 | 川崎製鉄株式会社 | Method for forming a heat-resistant top insulating film on grain-oriented silicon steel sheets |
| CA1089155A (en) * | 1975-08-29 | 1980-11-11 | Wilbur S. Hall | Treating autodeposited coatings with cr composition |
| DE2711431C2 (en) * | 1977-03-16 | 1986-12-11 | Metallgesellschaft Ag, 6000 Frankfurt | Process for the surface treatment of metals |
| US4183772A (en) * | 1978-01-30 | 1980-01-15 | Union Carbide Corporation | Composition and method for coating metal surfaces |
| US4227946A (en) * | 1979-02-09 | 1980-10-14 | Oakite Products, Inc. | No-rinse pre-paint coating composition and method |
| DE2907093A1 (en) * | 1979-02-23 | 1980-08-28 | Metallgesellschaft Ag | AGENT AND METHOD FOR PRODUCING NON-METAL COATINGS ON IRON AND STEEL |
| US4347085A (en) * | 1981-04-23 | 1982-08-31 | Armco Inc. | Insulative coatings for electrical steels |
| JPS58177475A (en) * | 1982-04-12 | 1983-10-18 | Nisshin Steel Co Ltd | Production of precoated metallic plate having excellent corrosion resistance, high workability and resistance to contamination |
| US4548646A (en) * | 1982-11-15 | 1985-10-22 | Sermatech International Incorporated | Thixotropic coating compositions and methods |
| US4544408A (en) * | 1983-04-18 | 1985-10-01 | Sermatech International Inc. | Thixotropic alumina coating compositions, parts and methods |
| JPS6039169A (en) * | 1983-08-12 | 1985-02-28 | Nippon Light Metal Co Ltd | Hydrophilic surface treating agent for metal |
-
1985
- 1985-03-15 CA CA000476688A patent/CA1256003A/en not_active Expired
- 1985-03-16 DE DE19853509556 patent/DE3509556A1/en not_active Withdrawn
- 1985-03-18 NZ NZ211485A patent/NZ211485A/en unknown
- 1985-03-19 EP EP85200412A patent/EP0155742B1/en not_active Expired - Lifetime
- 1985-03-19 DE DE8585200412T patent/DE3583512D1/en not_active Expired - Fee Related
- 1985-03-21 AR AR85299824A patent/AR242247A1/en active
- 1985-03-21 ZA ZA852128A patent/ZA852128B/en unknown
- 1985-03-22 AU AU40280/85A patent/AU580041B2/en not_active Ceased
- 1985-03-22 BR BR8501308A patent/BR8501308A/en not_active IP Right Cessation
- 1985-03-22 GB GB08507516A patent/GB2155962B/en not_active Expired
- 1985-03-22 MX MX204714A patent/MX166776B/en unknown
- 1985-03-23 JP JP60059342A patent/JPS60218483A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0422986B2 (en) | 1992-04-21 |
| BR8501308A (en) | 1985-11-19 |
| JPS60218483A (en) | 1985-11-01 |
| EP0155742A2 (en) | 1985-09-25 |
| AU580041B2 (en) | 1988-12-22 |
| NZ211485A (en) | 1988-07-28 |
| AU4028085A (en) | 1985-09-26 |
| DE3583512D1 (en) | 1991-08-29 |
| EP0155742A3 (en) | 1987-04-29 |
| MX166776B (en) | 1993-02-03 |
| GB8507516D0 (en) | 1985-05-01 |
| CA1256003A (en) | 1989-06-20 |
| ZA852128B (en) | 1985-11-27 |
| DE3509556A1 (en) | 1985-10-24 |
| GB2155962B (en) | 1987-12-31 |
| AR242247A1 (en) | 1993-03-31 |
| GB2155962A (en) | 1985-10-02 |
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