JP2000504781A - Zinc phosphate treatment method using low concentration of nickel and / or cobalt - Google Patents

Abstract

  (57) [Summary] A method of phosphating a metal surface of steel, galvanized steel or alloy galvanized steel and / or aluminum, wherein the metal surface is sprayed or dipped into a zinc-containing phosphating solution for 3 seconds to 3 hours. The contact is carried out for a time of 8 minutes, and the phosphating solution is selected from 0.2 to 3 g / l of zinc ions, 3 to 50 g / l of phosphate ions and 1 to 100 mg / l of nickel and / or cobalt ions. And / or a nitrate ion not exceeding 0.5 g / l. Components that may optionally be used include lithium, copper and / or manganese.

Description

DETAILED DESCRIPTION OF THE INVENTION        Zinc phosphate treatment method using low concentration of nickel and / or cobalt   The invention relates to zinc and phosphate ions and up to 100 ppm nickel and // using an acidic phosphating solution containing cobalt ions How to process. The present invention relates to such a method for subsequent painting, in particular electrical To be used as a preliminary treatment of metal surfaces for electrophoretic or powder coating Also concerns. This method is applicable to steel, galvanized steel or alloy galvanized steel, aluminum Suitable for surface treatment of aluminum, aluminum-plated steel or alloy aluminum-plated steel Can be used.   Metal phosphates that bond well to the metal surface when phosphated Is formed. The layer alone improves corrosion resistance and can be used with paints or other organic In combination with coatings, resists intrusion when in contact with corrosive substances, It contributes to substantially improving the adhesion of the material. This type of phosphating method is Has been known for many years. Preliminary treatment for painting, especially before electrophoretic painting If the phosphating solution has a relatively low concentration, for example 0.5 to 2 g / l zinc ions Is particularly stable. Such low zinc phosphorus One of the important characteristics of the phosphating bath is that the phosphate ion is heavy against zinc ion. It is a quantitative ratio, usually 8 or more, and may have a value of up to 30.   The use of other polyvalent metals in the zinc phosphate bath also significantly improved That a phosphate layer with excellent corrosion resistance and paint adhesion can be formed. Has also been found. As an example, for example, 0.5 to 1.5 g / l of manganese ion The low zinc method of adding nickel and, for example, 0.3 to 2.0 g / l nickel ions It has found widespread use as the so-called trication method, for painting metal surfaces, For example, it is used for cathode electrophoretic painting of automobiles.   Nickel and cobalt are sometimes used as substitutes, but toxicological and Are classified as serious (dangerous) in terms of Provides a similar level of performance as the Zion method, but with nickel and / or copper A need exists for a phosphating method that can lower the bath concentration of the Baltic. Have been. In recent years, methods that can be operated without using nickel at all have been developed. Was. However, this method does not cover all metal surfaces used in the automotive industry. The problem is that it is not possible to apply a uniform and good finish to the body with high reliability. ing.   DE-A-20 49 350 comprises, as an essential component, 3 to 20 g / l of phosphoric acid Salt ion, 0.5-3 g / l zinc ion, 0.003-0.7 g / l cobalt Ions or copper ions from 0.003 to 0.04 g / l, or preferably 0.03 to 0.04 g / l. Nickel ions of 0.5 to 3 g / l, magnesium ions of 1 to 8 g / l, 0.0 1 to 0.25 g / l nitrite ion and 0.1 to 3 g / l fluoride ion And / or a phosphating solution comprising 2 to 30 g / l chloride ion I have. Therefore, this method is useful if the phosphating solution is cobalt, copper or, preferably, nickel. A zinc / magnesium phosphate treatment is also described that also includes one type of ion. Although this type of zinc / magnesium phosphate treatment is said to be industrially successful, I want to.   EP-B-18 841 is promoted by chlorate / nitrite, in particular from 0.4 to 1 g / l zinc ion, 5-40 g / l phosphate ion and possibly less Nickel, cobalt, calcium, 0.2 g / l, preferably 0.2 to 2 g / l Treatment with zinc phosphate containing one or more ions selected from chromium and manganese Related to the solution. Therefore, the concentration of nickel or cobalt used in some cases may be low. It is at least 0.2 g / l. In this example, the nickel concentration is 0.53 to 1.33 g. / L.   EP-A-141 341 contains 0.1 to 5 g / l in addition to 10 to 50 g / l of zinc. phosphating solution comprising an amount of 1% nickel or cobalt. In this case, low Zinc phosphating is not a problem, but it can be used to prime stationary structures, such as bridges. As there is a problem. EP-A-287 133 may be up to 0.3 g / l Describes a zinc phosphate solution that may include cobalt in an amount of. The solution is essentially As an essential component, it contains 5 to 30 g / l of a nitrate salt.   It is an object of the present invention to provide a variety of materials used in the automotive industry with tricationic To provide a phosphate treatment method with reduced heavy metals that demonstrates the effects of the phosphate treatment method It is to be. This purpose is intended for steel, galvanized steel or alloy galvanized steel and / Or a method of phosphate treatment of a metal surface of aluminum, wherein the metal surface, By spraying or immersion, the phosphating solution containing zinc in a time of 3 seconds to 8 minutes A method of contacting, wherein the phosphating solution comprises: 0.2 to 3 g / l zinc ion, PO_Four3-50 g / l of phosphate ions, calculated as 1-100 mg / l nickel and / or cobalt ions, and   0.3-4 g / l chlorate ion,   0.01 to 0.2 g / l nitrite ion,   0.05 to 2 g / l of m-nitrobenzenesulfonate ion,   0.05 to 2 g / l of m-nitrobenzoate ion,   0.05 to 2 g / l p-nitrophenol,   0.005 to 0.15 g / l hydrogen peroxide (in free or bound form),   0.1 to 10 g / l of hydroxylamine (in free or bound form), and   0.1 to 10 g / l reducing sugar One or more accelerators selected from; Nitrate ions not exceeding 0.5 g / l This is achieved by a method characterized by including:   The zinc concentration is in the range from about 0.3 to about 2 g / l, especially in the range from 0.8 to 1.6 g / l. Preferably, there is. Zinc concentration in the range of 1.6 g / l or more, for example in the range of 2-3 g / l Does not provide much advantage to the method of the invention, while phosphoric acid Sludge generated in the salting bath may be increased. Such a zinc concentration is When phosphating a pickled surface, pickling erosion may occur. During operation, if more zinc enters the phosphating bath. It can happen in a bath. About 1 each of nickel and / or cobalt ions The above concentration range from about 100 mg / l to the lowest possible about 0.5 g / l Combined with nitrate concentrations that do not exceed Phosphating bath containing no nitrate and having a nitrate concentration of more than 0.5 g / l As a result, the corrosion resistance and the paint adhesion are improved. Nickel concentration is about 1 to about 50m g / l and / or the cobalt concentration can be from about 5 to about 100 mg / l. preferable. This allows for the efficiency of one phosphating bath and the flow of the other rinse water. Beneficial reconciliation with the processing needs of the outlet is achieved.   German patent application 195 00 927.4 discloses a composition of about 0.2 to about 1.5 g / l of lithium. Depending on the amount of umium ions, the corrosion resistance that can be achieved using a zinc phosphate treatment bath It discloses that the food effect is improved. About 0.2 to about 1.5 g / l, especially about 0.2 g / l Lithium ion concentrations of 4 to about 1 g / l have reduced heavy metals according to the present invention. It has a useful effect on the corrosion resistance effect achieved in the phosphating method. Rin The acid treatment solution may be used in place of or in addition to lithium, from about 0.001 to about It may also contain 0.03 g / l of copper ions. Such copper concentrations are particularly In combination with hydroxylamine as an agent, the anti-corrosion effect is further improved. Can be improved. When the method of the present invention is used for spraying, about 0.5 Copper concentrations of 001 to about 0.01 g / l are particularly useful. When used for immersion processing Preferably, the copper concentration is from about 0.005 to about 0.02 g / l.   The phosphating solution is in addition to or instead of lithium and / or copper ions When further containing manganese ions, the corrosion resistance action can be further improved. . In this case, manganese is preferably present in oxidation state 2. About 0.003 ~ With a manganese concentration of about 0.1 g / l, the efficiency of the phosphating bath and the treatment of effluents A beneficial harmony with the needs of management is shown and is therefore preferred. About 0.1 to about 4g / L, especially higher manganese concentrations of about 0.5 to 1.5 g / l, have a corrosion-resistant effect. Waste treatment and sewage of sludge, which may provide additional benefits If there is no problem with the processing, it can be used.   The particular combination of cations depends on the efficiency of the phosphating bath and the required slatting. It shows a good and thus favorable harmony between waste treatment and effluent treatment. In such a situation, in one preferred embodiment of the present invention, zinc ion, Containing lithium ions and copper ions in the above amounts, but not containing manganese ions. Use a phosphate treatment solution. In another preferred embodiment of the invention, a zinc ion, It contains cobalt ions and manganese ions in the above amounts, but nickel ions Use a phosphating bath that does not contain ions. In a third preferred embodiment of the present invention Are zinc, cobalt and lithium ions, and in some cases, manganese ions. A phosphating solution containing ON is used. In a fourth preferred embodiment of the present invention, Zinc, nickel and lithium ions, and possibly manganese A phosphating solution containing the ions in the amounts described above is used.   Incorporated in the phosphate coating or at least required for crystal growth in the phosphate layer In addition to the cations described above, which also have a useful effect, phosphating baths are generally free Sodium, potassium and / or ammonium ions are added to regulate the acid. contains. The expression "free acid" is used by those skilled in the art of phosphating. well known. Measure free and total acids used in the method of the invention The method is described in the examples. Free and total acids have a significant effect on layer weight Thus, it is an important control parameter of the phosphating bath. 0-1.5 points The free acid values in the range are for partial phosphating and values up to 2.5 points are Total acid for strip phosphating and ranging from about 15 to about 30 points Are within conventional ranges and are preferred in the context of the present invention.   For phosphating baths which are considered suitable for various substrates, up to 1 g / l Is free fluoride, the total fluoride being free up to an amount of up to 2.5 g / l It is customary to add and / or complexed fluoride. This amount of Fluo The presence of the lid is also advantageous in the phosphating bath according to the invention. H In the absence of luolide, the aluminum concentration in the bath exceeds 3 mg / l Should not be. When fluoride is present, the concentration of uncomplexed Al is 3 mg / higher Al concentration is acceptable for complex formation, provided that it does not exceed l. Is done. Therefore, the phosphated surface is at least partially converted to aluminum. When formed or contains aluminum, a fluoride-containing bath is advantageous. is there. In these cases, instead of uncomplexed fluoride, free It is advantageous to use the lid, preferably at a concentration of 0.5 to 1.0 g / l.   When phosphating zinc surfaces, the phosphating bath does not contain so-called accelerators. Good. However, when phosphating the steel surface, The treatment solution must contain one or more accelerators. Such accelerators include The components of the lead phosphating bath are conventional in the prior art. They are, Hydrogen formed on metal surfaces as a result of being attacked by acids in pickling solutions Is understood to be a substance that chemically binds to and is itself reduced. Oxidative promotion The iron (II) ions released on the steel surface by being attacked by the pickling solution Also has the effect of oxidizing to a trivalent state, so that the iron is ferric (III) phosphate As a precipitate.   The phosphating bath of the present invention comprises one or more of the following components as an accelerator: And may include:   0.3-4 g / l chlorate ion,   0.01 to 0.2 g / l nitrite ion,   0.05 to 2 g / l of m-nitrobenzenesulfonate ion,   0.05 to 2 g / l of m-nitrobenzoate ion,   0.05 to 2 g / l p-nitrophenol,   0.005 to 0.15 g / l hydrogen peroxide (in free or bound form),   0.1 to 10 g / l of hydroxylamine (in free or bound form), and   0.1 to 10 g / l reducing sugar.   When phosphating galvanized steel, use as little phosphating solution as possible. Should include nitrate. When the nitrate concentration is higher than 0.5 g / l Has a nitrate concentration of 0.5, since so-called "speck" may occur. g / l should not be exceeded. As a result, the phosphate layer has a white crater Defect can occur. In addition, paint adhesion to the galvanized surface is impaired. obtain.   The use of nitrous acid as a promoter, technically, especially on steel surfaces, Satisfactory results are obtained. However, there is a possibility that nitrous acid gas may be generated. Avoid the use of nitrous acid as an accelerator for industrial safety reasons). Is recommended. This phosphates the galvanized surface In some cases, nitrite can be formed from nitrous acid, and as described above, nitrous acid It leads to the problem of "staining" and can reduce the adhesion of paint to zinc It is recommended for technical reasons.   Hydrogen peroxide for environmental reasons and hydroxylamine for technical reasons , Are particularly preferred as accelerators. These are added to the solution at a later stage. If it needs to be added, it offers the possibility of a simple formulation. But Et al., The use of these two accelerators interchangeably can be attributed to hydrogen peroxide. Not recommended because silamines decompose. Hydrogen peroxide in free form or When used as an accelerator in a bonded form, the concentration range of hydrogen peroxide is between 0.005 and 0.5. Particularly preferred is 02 g / l. In this case, the hydrogen peroxide is It is thus added to the liquid. Nevertheless, hydrogen peroxide is recovered by a hydrolysis reaction. Hydrogen peroxide in a combined form, such as a compound that supplies hydrogen peroxide in a phosphate treatment bath Can also be used. Examples of such compounds include persalts, such as , Percarbonate, peroxosulfate or peroxodisulfate and so on. Further suitable sources of hydrogen peroxide include ionic peroxides, e.g. There are, for example, lukali metal peroxide. In a preferred embodiment of the present invention, the immersion method Phosphating involves the use of a combination of chlorate ions and hydrogen peroxide. I will. In this embodiment, the concentration of chloric acid may be, for example, 2-4 g / l. Alternatively, the concentration of hydrogen peroxide may be from 10 to 50 ppm.   Reducing sugars as accelerators are known from US-A-5 378 292. Return The original sugar is, according to the invention, from about 0.01 to about 10 g / l, preferably from about 0.5 to about 2 g / l. It can be used in amounts in the range of 0.5 g / l. Examples of this type of sugar include gala These include fructose, mannose and, in particular, glucose (dextrose).   In another preferred embodiment of the present invention, hydroxylamine is used as an accelerator. Is included. Hydroxylamine, as a free base, is hydroxyl As an amine complex (shown as the condensation product of hydroxylamine and ketone Oxime) or as a hydroxylammonium salt it can. Free hydroxylamine to phosphating bath or phosphating bath concentrate When added to hydroxylamine, mainly due to the acidic nature of those solutions, As a hydroxylammonium cation. Hydroxyla When used as ammonium salts, sulfates and phosphates are particularly preferred. is there. In the case of phosphates, acid salts are preferred for good solubility. Hydroxy Silamines or their compounds have a theoretical free hydroxylamine concentration of 0.1. 10 to 10 g / l, preferably 0.3 to 5 g / l in the phosphating bath. Is added. In this case, the phosphating bath is only hydroxylamine as accelerator And, if necessary, with a maximum amount of nitrate of 0.5 g / l. Good. Thus, in a preferred embodiment, the phosphating bath comprises another known accelerator. For example nitrous acid, oxoanions of halogens, peroxides or nitrobenzenes Used without sulfonate. As a useful side effect, about 1.5 g / l Exceeding hydroxylamine concentrations in the parts to be phosphatized The possibility that rust is generated in a portion where the surrounding is insufficient is reduced.   In fact, the promoter hydroxylamine is used when the metal moiety to be phosphatized is phosphorous. It has also been found that if not introduced into the bath, it can be gradually deactivated. Have been. Surprisingly, one or more aliphatic hydrides having 2 to 6 carbon atoms Loxycarboxylic acid or aminocarboxylic acid in a total amount ranging from 0.01 to 1.5 g / l When added, hydroxylamine inactivation can be significantly delayed. It has also been found that it can. In this case, the carboxylic acid is glycine, lactic acid, May be selected from gluconic acid, tartronic acid, malic acid, tartaric acid and citric acid Preferably, citric acid, lactic acid and glycine are particularly preferred.   EP-A-361 375 has a gear ratio of 0.3 to 5 g / l, preferably 1 to 3 g / l. It is disclosed that an acid is added to the nickel-containing phosphating bath. With formic acid Thus, nickel causes a stronger adhesion to the metal surface and / or Better incorporation into salt crystals. This effect can also be translocated to cobalt it is conceivable that. The addition of formic acid has a low nickel and / or cobalt concentration. It is also advantageous for the purpose of the present invention.   When the phosphating method is applied to steel surfaces, the iron is in solution in the form of iron (II) ions. Enter. The phosphating bath of the present invention contains a substance capable of oxidizing iron (II). If not, divalent iron is converted to a trivalent state as a result of air oxidation and As a result, it precipitates as iron (III) phosphate. This is, for example, hydroxylamine Is used. Therefore, the concentration contained in the bath containing the oxidizing agent is much lower. Even higher concentrations of iron (II) can occur in the phosphating bath. In this case, 50 ppm Iron (II) concentrations above are common and values up to 500 ppm May occur for a short time. In the phosphating method of the present invention, The iron (II) concentration is not so harmful. When preparing with hard water, phosphate treatment The bath is Mg (II), which is a cation that forms hardness (cation that is a factor of hardness) And Ca (II) at a total concentration of up to 7 mmol / l. Mg (II) and C a (II) can also be added to the phosphating bath in amounts up to 2.5 g / l.   Ratio of phosphate ion to zinc ion in phosphating solution ( (By weight) varies widely, provided it is in the range of 3.7-30. obtain. A weight ratio in the range from 10 to 20 is particularly preferred. For phosphate concentration data Accordingly, the total phosphorus content of the phosphating bath is determined by the phosphate ion PO_Four ^3-In the form of It is thought to exist. Therefore, when calculating the quantity, it is usually about 3 to about 3.6. At the pH of the phosphate bath, a very small portion of the phosphate is actually trivalent. It is ignored that it is in the form of a negatively charged anion. Rather, at this pH Is that the phosphate is mostly a monovalent dihydrogen phosphate anion, It is accompanied by very small amounts of undissociated phosphate and divalently charged monohydrogen phosphate anions. It is believed to be.   Phosphating baths are generally sold in the form of aqueous concentrates, which are The application concentration is adjusted by adding water in place. For stability reasons, These concentrates contain excess free phosphoric acid and therefore dilute to bath concentration In such cases, the free acid value tends to be slightly higher at first and the pH tends to be slightly lower. Alkali, for example For example, by adding sodium hydroxide, sodium carbonate or ammonia, Lower the free acid value to the desired range. In addition, the concentration of free acid depends on the By the on-consumption and, possibly, the decomposition reaction of the accelerator. Is known to be able to rise over time during use of phosphate treatment baths . In this case, the free acid value is adjusted to the desired range by occasional addition of alkali. Need to readjust to the enclosure. This means that the alkali metal in the phosphating bath or That the concentration of ammonium ions can vary within a wide range; Have a tendency to increase over the life of the phosphating bath as a result of neutralization of free acids. It means that there is. Therefore, alkali metal ions and / or ammonia The weight ratio of calcium ions to zinc ions, for example, is In a salting bath, it may be very low, for example, less than 0.5, and in extreme cases it is zero. Although this may be the case, this value will generally increase over time as a result of bath maintenance. , And thus may be more than one, up to ten or more Is also acceptable. Low zinc phosphating bath is PO_Four ^3-: The desired value of Zn is 8 or less As above, alkaline so that the free acid can be adjusted to the required concentration It is generally necessary to add metal ions or ammonium ions. other Bath components such as alkali metal ions or ammonium for phosphate ions The same can be considered for the ratio of muons.   In the case of lithium-containing phosphating baths, the advantages of lithium with respect to the corrosion resistance action are: It is controlled by very high sodium concentrations, and is The use of thorium compounds should be avoided. In this case, adjust the free acid For this purpose, it is preferable to use a basic lithium compound. Support this treatment For this purpose, potassium compounds are also suitable.   Basically, into the phosphating bath, the cations that form or affect the layer It is not very important how the application is introduced. Of course, books Nitrate should be avoided so as not to exceed the upper limit of the nitrate concentration of the invention . Metal ions are in the form of compounds that do not introduce other ions into the phosphating bath It is preferred to use. Therefore, use metals in the form of their oxides or carbonates. for It is most advantageous to Lithium is used as sulfate and copper is used as acetate. Can also be used. Phosphate treatment that particularly satisfies the ecological objectives of the present invention The type of the solution should not exceed 0.5 g / l of other divalent cations in addition to zinc ions. Not to be included in the total amount.   The phosphating solution of the present invention is a steel, galvanized steel or alloy galvanized steel, Refining the surface of aluminum, aluminum plated steel or alloy aluminum plated steel It is suitable for phosphate treatment. Here, the expression “aluminum” is Commercially available aluminum alloys, such as AlMg0.5Si1.4, are included. The above Materials are becoming more and more commonplace in the automotive industry, are doing.   Therefore, parts of the body of the car are made of materials that have already been prepared, for example Bonazink (Registered trademark) process. In this case, the basic material is first chromated or phosphated and then After that, it may be coated with an organic resin. The phosphate method of the present invention The method then comprises phosphate treatment of the damaged area in the prepared layer. Can lead to treatment or lead to phosphate treatment of other parts that are not You can also.   The method of the present invention can be applied to dipping, spraying or spraying / dipping. Wear. Especially in the automotive industry, the processing time is 1 to 8 minutes, especially 2 to 5 minutes. In such a case, it can be used usually. Processing time of 3 to 12 seconds It can also be used for phosphate treatment of strips in the processing of steel enclosures. is there. When used for phosphating strips, the bath concentration is adjusted according to the invention. It is recommended to set the value in the higher half range in the preferred range of. For example, the zinc concentration may be 1.5-2.5 g / l and the free acid concentration 1.5-2.5 g / l. It may be 5 points. Galvanized steel, especially electric galvanized steel It is particularly suitable as a substrate for strip phosphate treatment.   As with other known phosphate baths, suitable bath temperatures are in the range of 30-70 ° C. In other words, a temperature range of 45 to 60 ° C. is preferable, regardless of the field of application.   The phosphating method of the present invention can be used before painting, for example, in the shades With particular intent to treat the metal surface as described above prior to the pole induction coating I have. In addition, powder coatings, such as those used in household appliances, etc. It is also suitable as a preliminary treatment before mounting. Phosphating methods are technically conventional. It can be viewed as a stage in a preparative processing chain. In this processing chain, Prior to the phosphating process, a cleaning / degreasing step including an intermediate rinse and activation is placed. Usually, activation is performed using an activator containing titanium phosphate It is common. After the phosphating according to the invention, with an intermediate rinsing or Without passivation, post-passivation treatment can be performed. Treatment baths containing chromic acid It can be widely used in this kind of post-passivation treatment. However, industrial safety For reasons of environmental protection and waste disposal, these chromium-containing passivations Baths tend to be replaced by treatment baths that do not contain chromium. For this purpose, pure Inorganic bath solutions, especially solutions based on zirconium compounds, or organic reactive baths Solutions, for example, poly (vinylphenol) based solutions are known. Specific phosphoric acid Following the salt treatment method, selected from lithium ions, copper ions and / or silver ions 0.001 to 10 g / l of one or more cations, from about 3 to about 7 The fact that rinsing can be performed after passivation using an aqueous solution having a pH German Patent Application 195 11 573.2. Rinse after this kind The phosphating method of the present invention, especially when the phosphating solution does not contain copper, It is also suitable for improving the corrosiveness. For this purpose, 0.002-1 g / l It is preferable to use an aqueous solution containing copper ions. Copper is used as acetate Preferably. In particular, such post-rinse solutions have a pH in the range of 3.4 to 6. And preferably has a temperature of 20 to 50C.   Intermediate rinsing with fully deionized water generally involves a post-passivation process. And a coating process, which is usually performed subsequently.Example   The phosphating method of the present invention and the method of the comparative example are used, for example, in the automobile industry. The used St1405 steel plate and electrogalvanized steel plate were tested. Car The following series of processing steps typically applied to the manufacture of a car body (body) Went):   1. Alkaline cleaner (Ridoline® 1559, Henke) Purification with a 2% solution in city water of Henkel KGaA, 55 ° C, 4 minutes.   2. Rinse with city water, room temperature, 1 minute.   3. Activator containing titanium phosphate (Fixodine® C91 12, Henkel's product), in a well deionized 0.1% solution in water , Room temperature, 1 minute.   4. Phosphating with the phosphating bath of Table 1. 55 ° C temperature, 4 minutes. Table 1 Phosphating bath controls free acid content, if necessary, other than the cations described in To contain sodium ions. Li-containing phosphating bath is Nato It did not contain lium. All baths are 0.95 g / l SiF₆ ^2-And 0.2 g / l F^-Was included.   The free acid value was 1.0-1.1 points and the total acid value was 23-25 points. Was. The number of free acid points is determined by titrating 10 ml of the bath solution to a pH of 3.6. It is understood to be the required consumption of 0.1 N sodium hydroxide in ml. Similarly, the total acid point number indicates the amount consumed in ml up to a pH value of 8.2.   5. Rinse with city water, room temperature, 1 minute.   6. 0.25% strength zirconium fluoride in fully deionized water Complex-based chromium-free passivating agent (Deoxylyte® 54) NC, Henkel product), pH 4.0, temperature 40 ° C, 1 minute (In Table 1, it is represented by "Zr"). Alternatively, 50 mg of Cu (II) (as acetate) / L and a pH of 3.6 (adjusted by acetic acid) followed by a 45 ° rinse with the rinsing solution. Post-passivation was carried out at a temperature of ° C. for 1 minute (represented in Table 1 by “Cu”).   7. Rinse with deionized water.   8. Air blowing with compressed air.   The area specific weight ("layer weight") is 5% according to DIN 50942. Measured by dissolving in chromic acid solution. This is 1.5-3.5 g / m^TwoRange.   The phosphate-treated sample was used as a cathodic electrophoretic paint (manufactured by BASF, FT85-7). 042). Corrosion resistance tests on galvanized steel VDA-Wechselklimatest alternate weathering Sex Test) 621-415, with 5 cycles under climatic conditions. Scraping Table 1 also shows the results of the progress of rust under the paint at the scratched area (half width of the scratch). ing. Table 1 shows that the results of the stone impact test are also based on the VW standard (the smaller the K value, the more the paint adheres. Properties are improved).   The corrosion resistance test for steel sheets is carried out according to DIN 50021 (1008 hours) Tested by spraying. Table 1 shows the paint of the scratched part (half-width of the scratch). This shows progression on the lower side. Table 1: Phosphating bath, post-passivation and corrosion resistance results (Steel: salt spray test; galvanized steel: alternating climatic test)

────────────────────────────────────────────────── ─── Continuation of front page    (81) Designated countries EP (AT, BE, CH, DE, DK, ES, FI, FR, GB, GR, IE, IT, L U, MC, NL, PT, SE), AU, BR, BY, C A, CN, CZ, HU, JP, KR, MX, NZ, PL , RO, RU, SG, SI, SK, TR, UA, US, VN (72) Inventor Gottwald, Carl-Heinz             Federal Republic of Germany Day-50374 Elftsi             Sutat, Auf dem Deutschen 10 (72) Inventor Meyer, Bernd             Federal Republic of Germany Day-40597 Düssel             Dorf, Hospitalitalstrasse 18 (72) Inventor Combe, Peter             Federal Republic Day-40724 Hilden,             Clarenbachweg No. 3

Claims (1)

[Claims] 1. A method of phosphating a metal surface of steel, galvanized steel or alloy galvanized steel and / or aluminum, wherein the metal surface is sprayed or immersed in a phosphating solution containing zinc for 3 seconds to 3 hours. Contact for 8 minutes, the phosphating solution contains 0.2-3 g / l zinc ion, calculated as PO ₄ , 3-50 g / l phosphate ion, 1-100 mg / l nickel and And / or cobalt ion, and 0.3 to 4 g / l chlorate ion, 0.01 to 0.2 g / l nitrite ion, 0.05 to 2 g / l m-nitrobenzenesulfonate ion, 0.05 to 5 g / l 2 g / l m-nitrobenzoate ion, 0.05 to 2 g / l p-nitrophenol, 0.005 to 0.15 g / l hydrogen peroxide (free or bound form), 0.1 to 10 g / l l Loxylamine (in free or bound form) and one or more accelerators selected from 0.1 to 10 g / l reducing sugars; and nitrate ions not exceeding 0.5 g / l. how to. 2. 2. The method according to claim 1, wherein the phosphating solution contains 1 to 50 mg / l nickel ions and / or 5 to 100 mg / l cobalt ions. 3. 3. The method according to claim 1 or 2, wherein the phosphating solution also contains 0.2 to 1.5 g / l of lithium ions. 4. The method according to any of claims 1 to 3, wherein the phosphating solution also contains 1 to 30 mg / l of copper ions. 5. The method according to any of claims 1 to 4, wherein the phosphating solution also contains 3 to 100 mg / l of manganese ions. 6. The method according to any of claims 1 to 4, wherein the phosphating solution also contains 0.1 to 4 g / l of manganese ions. 7. The method according to any one of claims 1 to 4, wherein the phosphating solution contains zinc ions, cobalt ions, and copper ions and does not contain manganese ions. 8. The method according to any one of claims 1 to 6, wherein the phosphating solution contains zinc ions, cobalt ions and manganese ions, and does not contain nickel ions or copper ions. 9. A method according to any of claims 1 to 6, wherein the phosphating solution comprises zinc ions, cobalt ions and lithium ions, and optionally manganese ions. 10. A method according to any of claims 1 to 6, wherein the phosphating solution comprises zinc ions, nickel ions and lithium ions, and optionally manganese ions. 11. Phosphating solution, respectively F ^- calculated as, include fluoride in the amount of total fluoride to 2.5 g / l, or in the range of 1 to 10 claims 1 g / l of which is a free fluoride The method described in. 12. 12. The method according to any of claims 1 to 11, wherein the phosphating solution contains 5-150 mg / l of hydrogen peroxide in free or bound form as promoter. 13. 12. The process according to claim 1, wherein the phosphating solution contains 0.1 to 10 g / l of hydroxylamine in free or bound form as promoter. 14． 12. The phosphating solution according to claim 1, wherein the phosphating solution contains one or more aliphatic hydroxycarboxylic acids or aminocarboxylic acids having 2 to 6 carbon atoms in a total amount of 0.01 to 1.5 g / l. The method described in Crab. 15. The method according to any of claims 1 to 14, wherein the phosphating solution comprises 0.3 to 5 g / l formic acid. 16. 16. The phosphating solution according to claim 1, wherein the phosphating solution contains, in addition to zinc ions, other divalent cations in a total amount not exceeding 0.5 g / l. Method. 17． After the metal surface has been treated with the phosphating solution and prior to painting, one or more cations of lithium, copper and / or silver ions may be added in an amount of 0.001 to 10 g / l. The method according to any one of claims 1 to 16, wherein rinsing is performed after passivation using an aqueous solution having a total pH of 3 to 7. 18. The method according to claim 17, wherein the post-rinsing is carried out using an aqueous solution containing 18.001 to 1 g / l of copper ions.