MXPA00002319A - Pretreatment before painting of composite metal structures containing aluminum portions - Google Patents

Abstract

In a process for the chemical pretreatment before painting of composite metal structures that contain aluminum or aluminum alloy portions together with steel, galvanized steel and/or alloy-galvanized steel portions, in a first step the metal structure is treated with a zinc phosphating solution that forms a surface-covering crystalline zinc phosphate layer on steel and on galvanized or alloy-galvanized steel, but without forming a zinc phosphate layer on the aluminum portions, and then in a second step the metal structure is brought into contact with a treatment solution that does not excessively dissolve the crystalline zinc phosphate layer on steel, galvanized and/or alloy-galvanized steel, but forms a conversion layer on the aluminum portions.

Description

TREATMENT OF COMPOSITE METALLIC STRUCTURES CONTAINING PARTS OF ALUMINUM PREVIOUSLY TO THE APPLICATION OF PAINT BACKGROUND OF THE INVENTION For many reasons, such as weight, rigidity or possibility of recycling, aluminum is being used more and more in the automotive industry. In the context of this invention, the term "aluminum" refers not only to pure aluminum, but also to aluminum alloys whose main component is aluminum. Examples of commonly used alloying elements are silicon, magnesium, copper, manganese, chromium and nickel, the total proportion by weight of these alloying elements in the alloy normally does not exceed 10%. While engine parts and gears, wheels, seat structures, etc., already contain significant amounts of aluminum, the use of aluminum in the construction of the body is currently limited to parts such as chests, rear trunks, internal parts of door, and several small parts as well as truck cabins, side walls of conveyors or add-ons for minivans. Globally, on a global scale, less than 5% of the metallic surface of car bodies is made of aluminum. The growing use of aluminum in this sector is under intensive research by the aluminum and automotive industries.

This invention relates to a process for a pretreatment of corrosion prevention prior to the application of paint on metal composite structures containing aluminum and / or aluminum alloy parts as well as steel and / or galvanized steel parts. The process is particularly envisaged for use in the manufacture of automobiles. In the manufacture of automobiles, bodies or body parts containing structural portions of aluminum and / or their alloys as well as structural portions of steel and / or galvanized steel are subjected to a chemical pretreatment conversion prior to the application of paint. As for this aspect, a cathodic coating electrodeposited by immersion is currently used as the first step of applying paint. The process according to the present invention is essentially suitable as pretreatment for this step. The process differs from previous conventional pretreatment processes in the manufacture of automobiles insofar as a layer of zinc phosphate coating surface is deposited in a first stage on the surfaces of steel and / or galvanized steel, without coating the aluminum surfaces to a large degree. A second step comprises a treatment with a solution which does not excessively attack the previously formed zinc phosphate layer, and which preferably increases its corrosion prevention action, and simultaneously forms a surface layer on the aluminum surfaces. A two-stage process is therefore involved, said first step comprising a conventional zinc phosphating. Obviously, it is a necessary condition that a zinc phosphating solution is used that does not form a layer on the aluminum. In these zinc phosphating solutions are known in the prior art and references will be mentioned by way of example below. In the second stage, solutions with constituents are used that are effective to form a protective layer on the aluminum. Regarding this aspect, the nature and concentration of these solutions should be chosen in such a way that on the one hand a layer is reliably formed on the aluminum surfaces, but on the other hand, the crystalline zinc phosphating layers formed in the Iron and / or zinc surfaces are not damaged excessively. The purpose of metal phosphating is the production of phosphate metal layers that adhere firmly to the metal surface which improves the corrosion resistance already existing per se, and in combination with paints or other organic coatings, contributes to a substantial improvement in coating adhesion and slip resistance in the case of corrosive condition.

These phosphating processes have been known for a long time. For pretreatment before paint application, especially in the case of dip electroplated coating, low zinc phosphating processes in which the phosphating solutions contain relatively low concentrations of zinc ions, for example 0.5 to 2 grams per liter, usually abbreviated below as "g / 1", are especially suitable. A basic parameter in these phosphate baths with low zinc content is the weight ratio between phosphate ions and zinc ions, which is normally above 8 and can reach values of up to 30. It has been found that the phosphate layers with substantially prevention Improved corrosion and improved paint adhesion properties can be formed by the co-use of other polyvalent cations in zinc phosphating baths. For example, processes with low zinc content with the addition, for example, of 0.5 to 1.5 g / 1 of manganese ions and, for example, 0.3 to 2.0 g / 1 of nickel ions are widely used in what are known as processes of "tricathion" to prepare metallic surfaces for application of paint, such as by electrodeposited cathodic coating by immersion of car bodies. Since nickel and its alternative, cobalt, are classified as hazardous materials from a toxicological and effluent treatment perspective, efforts are currently being made to find phosphating processes that are as effective as tricathion processes but that employ concentrations significantly less nickel and / or cobalt and preferably do not use these two metals. EP-A-459 541 describes phosphate solutions essentially free of nickel and containing, in addition to zinc and phosphate, from 0.2 to 4 g / 1 of manganese and from 1 to 30 milligrams per liter, usually abbreviated here as "mg / l ", copper. From DE-A-42 19 513, nickel-free phosphating solutions are known that contain, in addition to zinc and phosphate, from 0.5 to 25 mg / l of copper ions as well as hydroxylamine as an accelerator. These phosphating solutions also optionally contain from 0.15 to 5 g / 1 of manganese. German patent application DE 196 06 017.6 describes a phosphating solution, with a decreased concentration of heavy metals, containing 0.2 to 3 g / 1 of zinc ions, 1 to 150 mg / l of manganese ions, and 1 to 30 mg / l of copper ions. This phosphating solution can optionally also contain up to 50 mg / l of nickel ions and up to 100 mg / l of cobalt ions. An additional optional constituent is lithium ions in amounts between 0.2 and 1.5 g / 1.

DE 195 38 778 describes the weight control of the phosphate layer coating by the use of hydroxylamine as an accelerator. The use of hydroxylamine and / or its compounds in order to influence the shape of the phosphate crystals is known from several publications. EP-A-315 059 presents as a special effect of the use of hydroxylamine in phosphating baths the fact that in steel the phosphate crystals continue to occur in the desired column or node form, even if the zinc concentration in the phosphating bath exceeds the conventional range for processes with low zinc content. In this way, it is possible to operate the phosphating baths with concentrations of up to 2 g / 1 and with weight ratios between phosphate and zinc from 3.7. The required hydroxylamine concentration is within a range of 0.5 to 50 g / 1, preferably 1 to 10 g / 1. WO 93/03198 discloses the use of hydroxylamine as an accelerator in tricathion phosphating baths with zinc contents between 0.5 and 2 g / 1 and nickel and manganese contents in each case from 0.2 to 1.5 g / 1, proportions of specific weights between zinc and the other divalent cations maintained. further, these baths contain from 1 to 2.5 g / 1 of a "hydroxylamine accelerator", which, according to the description, refers to hydroxylamine salts, preferably hydroxylamine ammonium sulfate. In order to improve the prevention of corrosion caused by the phosphate layer, what is generally known in this technology is used as a rinse after passivation or post-passivation. Treatment baths containing chromic acid are still used to a large extent for this purpose. For reasons of environmental protection and workplace safety there is a tendency, however, towards the replacement of these chrome-containing passivation baths with chrome-free treatment baths. Organoreactive bath solutions containing substituted poly (vinylphenols) forming complexes are known for this purpose. Examples of compounds of this type are described in DE-C-31 46 265. Particularly effective polymers of this type contain amine substituents and can be obtained by a Mannich reaction between poly (vinylphenols) and aldehydes and organic amines. Such polymers are described, for example, in EP-B-91 166, EP-B-319 016 and EP-B-319 017. Polymers of this type are also used within the scope of the present invention, and therefore the The contents of the four documents just mentioned, except insofar as they are inconsistent with any of the teachings herein, are incorporated herein by reference. The use of such polyvinylphenol derivatives for the surface treatment of aluminum is known, for example, from EP-B-319 016 mentioned above. WO 90/12902 presents a chromium-free coating for aluminum, the aluminum surfaces are in contact with a treatment solution having a pH within a range of about 2.5 to about 5.0 and contains, in addition to polyvinylphenol derivatives, also phosphate ions as well as fluoroacids of the elements zirconium, titanium hafnium and silicon. US-A-5 129 967 presents treatment damage for a non-rinsing treatment (here means "on-site dried conversion coating") of aluminum, which contains: (a) from 10 to 16 g / l of polyacrylic acid or acrylic acid copolymers, (b) from 12 to 19 g / l of hexafluorozirconic acid, (c) from 0.17 to 0.3 g / l of hydrofluoric acid, and (d) up to 0.6 g / l of hexafluorotitanic acid. EP-B-8 942 presents treatment solutions, preferably for aluminum cans, which contains: (a) from 0.5 to 10 g / 1 of polyacrylic acid or an ester thereof, (b) from 0.2 to 8 g / 1 of at least one of the compounds H2ZrF6, H2TiF6 and H2SiF6, the pH of the solution is less than 3.5, as well as an aqueous concentrate to replenish the treatment solution, which contains: (a) from 25 to 100 g / 1 of polyacrylic acid or an ester thereof, (b) from 25 to 100 g / 1 of at least one of the compounds H2ZrF6, H2TiF6 and H2SÍF6, and (c) a source of free fluoride ions providing from 17 to 120 g / 1 free fluoride. DE-C-19 33 013 presents treatment baths with a pH above 3.5, which in addition to complex boron fluorides, titanium or zirconium in amounts of 0.1 to 15 g / 1, measured as its stoichiometric equivalent as boron, titanium , or zirconium as appropriate, also contain 0.5 to 30 g / 1 of oxidizing agent, especially sodium meta-nitrobenzenesulfonate. DE-C-24 33 704 describes treatment baths for improving paint adhesion and permanent corrosion prevention, inter alia, in aluminum, which may contain from 0.1 to 5 g / 1 of polyacrylic acid or its salts or esters as well as from 0.1 to 3.5 g / 1 of ammonium fluorozirconate, calculated as Zr02. The pH of these baths can vary within wide ranges. The best results are generally obtained when the pH is within a range of 6 to 8. US-A-4 992 116 discloses treatment baths for the aluminum conversion treatment with pH values comprised within a range of approximately 2.5 to 5, which contain at least three components: (a) phosphate ions in a concentration range comprised between l. lxlO-5 and 5.3xl 0"3 mol / l, which corresponds to a range of 1 to 500 mg / l, (b) from l.lxlO-5 to 1.3xl0 ~ 3 mol / liter, which is usually abbreviated here as "mol / 1", of a fluoroacid of an element of the group Zr, Ti, Hf and Si (corresponding to a range of 1.6 to 380 mg / l of each element) and (c) from 0.26 to 20 g / 1 of a polyphenol compound obtainable by the reaction of poly (vinylphenol) with aldehydes and organic amines A molar ratio between fluoroacid and phosphate of about 2.5: 1 to about 1:10 should be maintained. 27 15 292 presents treatment baths for the chromium-free pretreatment of aluminum cans, which contain at least 10 parts by million by weight, which is usually abbreviated below as "ppm", of titanium and / or zirconium, among others. and 1000 ppm of phosphate, and a sufficient amount of fluoride, but at least 13 ppm, to form complex fluorides of titanium and / or zirconium present, and have pH values c omitted within a range of 1.5 WO 92/07973 presents a chromium-free treatment process for aluminum, which employs as essential components in aqueous acid solution from 0.01 to about 18% by weight of H2ZrF6 and from about 0.01 to about 10% by weight of a polymer of 3- (N-C 1 -C 4 -N-2-hydroxyethyl-aminomethyl) -4-hydroxystyrene. Optional components include 0.05 to 10% by weight of dispersed Si2, 0.06 to 0.6% by weight of a solubilizing agent for the polymer, as well as a surfactant. The aforementioned polymer is included among the "reaction products of poly (vinylphenol) with aldehydes and amines containing organic hydroxyl groups" described below and which may be employed within the scope of the present invention. In practice, it has been found that in the joint phosphating of aluminum surfaces and surfaces of steel and / or galvanized steel, technical compromises must be accepted in terms of the composition of the phosphating baths. Aluminum ions released from the aluminum surface by chemical attack and decanting action act as bath venom for the production of phosphating and interfere with the formation of zinc phosphate crystals on iron surfaces. The dissolved aluminum must therefore be precipitated or masked through appropriate measures. For this purpose, fluoride ions attached to complexes or free are usually added to the phosphating baths.

Fluoride ions mask aluminum ions through the formation of complexes and / or precipitate these ions as sodium and / or potassium hexa-fluoroaluminates if the solubility products of the corresponding salts are exceeded. In addition, free fluoride ions usually cause an increased chemical attack on the aluminum surfaces, with the result that a more or less closed and sealed zinc phosphate layer can be formed on said surfaces. The joint phosphating of aluminum structural portions with structural portions of steel and / or galvanized steel therefore has the technical disadvantage that phosphating baths must be monitored very precisely in terms of their fluoride content. This increases the control and monitoring work involved and may require storage and measurement of fluoride-containing solutions as separate replenishment solutions. Likewise, the precipitated salts of hexafluoroaluminate increase the amount of phosphating sludge and raise the cost of its removal and disposal. Accordingly, there is a need for pretreatment processes for complex structural parts, for example automobile bodies, which contain in addition to aluminum portions, also portions of steel and / or galvanized steel. The formulation range for phosphating baths must be expanded and the control and monitoring work must be reduced. The result of the overall pretreatment should be the formation of a conversion layer on all exposed metal surfaces which is suitable as a paint substrate which prevents corrosion, especially before a electrodeposited electrodeposited coating. COMPENDIUM OF THE INVENTION This object is achieved through a process for the chemical pretreatment before an organic coating, of composite metal structures containing portions of aluminum or aluminum alloys together with portions of steel, galvanized steel and / or galvanized steel alloy, characterized by: (I) the treatment in a first step of the composite metal structure with a zinc phosphating solution which forms a layer of crystalline zinc phosphate in the steel and in the galvanized steel and / or alloyed galvanized steel surface coating having a coating weight within a range of 0.5 to 5 g / m2, but without forming a layer of zinc phosphate in the aluminum portions; and subsequently, with or without intermediate rinse with water, (II) having in contact in a second step the composite metal structure with a treatment solution that does not dissolve more than, with increasing preference in the given order, 60, 50, 40, 30, 20, 15, 10, 8 or 6% of the crystalline zinc phosphate layer formed in the steel, galvanized steel, and / or galvanized steel alloyed in step (I), but which produces a conversion layer in the aluminum portions. The stipulation in the sense that no zinc phosphate layer should be formed in the aluminum portions in the treatment step (a) should be understood as meaning that a closed and sealed crystalline layer is not formed and that the mass per area unit of any zinc phosphate deposited does not exceed 0.5 grams per square meter, which is usually abbreviated below as "g / m2". In order to comply with this condition, the phosphating baths can be formulated arbitrarily insofar as specific conditions for the fluoride concentration are observed. These conditions can be found in EP-B-452 638. This document summarizes the conditions under which a closed zinc phosphate layer is formed on aluminum surfaces. According to the present disclosure, the concentration of free fluoride ions, for example, measured in g / 1, must comply with the condition that, at a specific temperature T (in ° C), is above a value of 8. / T. However, since within the scope of the present invention no zinc phosphate layer should be formed in the aluminum in the phosphating step (I), in contrast to the teachings of EP-B-452 638, a a specific temperature T (in ° C), the concentration of free fluoride ions (in g / 1) in the phosphating solution must be below 8 / T. DETAILED DESCRIPTION OF THE INVENTION Accordingly, in the phosphating step (I) a zinc phosphating solution having a pH within a range of about 2.5 to about 3.6 and a temperature within a range of about 20 to about 65 ° C, and which does not contain more free fluoride in g / 1 than specified by the expression 8 / T, "T" referring to the bath temperature in ° C, is preferably used. Independently for each mentioned component, this zinc phosphating solution also preferably comprises: from 0.3 to 3 g / 1 of Zn (II), from 5 to 40 g / 1 of phosphate ions, and at least one of the following accelerators: from 0.3 to 4, or more preferably from 1 to 4, g / 1 of chlorate ions, from 0.01 to 0.2 g / 1 of nitrite ions, from 0.05 to 2, or more preferably from 0.2 to 2, g / 1 of m-nitrobenzenesulfonate ions, of 0.05 to 2 g / 1 of m-nitrobenzoate ions, of 0.05 to 2 g / 1 of p-nitrophenol, of 0.001 to 0.15, or more preferably of 0.001 to 0.070, g / 1 of hydrogen peroxide in free or bound form, from 0.1 to 10 g / 1 of hydroxylamine in free or bound form and from 0.1 to 10 g / 1 of a reducing sugar. Experience shows that the prevention of corrosion and adhesion of the paint of the crystalline zinc phosphate layers formed in such a phosphating bath improves if the zinc phosphating solution in step (I) also contains a several of the following cation concentrations: from 0.001 to 4 g / 1 manganese (II); from 0.001 to 4 g / 1 of nickel (II), from 0.002 to 0.2 g / 1 of copper (II), from 0.2 to 2.5 g / 1 of magnesium (II), from 0.2 to 2.5 g / 1 of calcium (II) ), from 0.01 to 0.5 g / 1 of iron (II), from 0.2 to 1.5 g / 1 of lithium (I), and from 0.02 to 0.8 g / 1 of tungsten (VI). The concentration of zinc is more preferably within the range between about 0.8 and about 1.6 g / 1. Zinc concentrations above 1.6 g / 1, for example, between 2 and 3 g / 1, provide only slight advantages for the process, but on the other hand they can increase the incidence of sludge in the phosphating bath. Such zinc concentrations are adjusted in a working phosphating bath if during the phosphating of galvanized surfaces additional zinc passes into the phosphating bath through its chemical attack action. Nickel and / or cobalt ions in a concentration range in each case between about 1 and about 50 mg / l in the case of nickel and about 5 to about 100 mg / l in the case of cobalt in combination with the lowest possible content of nitrate, no more than approximately 0.5 g / 1, improve the prevention against corrosion and paint adhesion compared to phosphate baths that do not contain nickel or cobalt or that have a nitrate content greater than 0.5 g / 1. In this way, a favorable compromise is reached between the performance of the phosphating baths on the one hand and the requirements of the treatment of the effluents from the rinsing waters on the other hand. With phosphating baths containing reduced amounts of heavy metals, the manganese content may be within a range of about 0.001 to 0.2 g / 1. Otherwise, the manganese content is from about 0.5 to about 1.5 g / 1 conventionally. It is known from DE-A-195 00 927 that lithium ions in amounts of about 0.2 to about 1.5 g / 1 improve the corrosion prevention that can be obtained with zinc phosphating baths. Lithium concentrations within the range of 0.2 to about 1.5 g / 1 and particularly of about 0.4 to about 1 g / 1 also have a beneficial effect on the resulting prevention against corrosion with the phosphating process according to the invention and subsequent treatment subsequent Apart from the cations mentioned above, which are incorporated into the phosphate layer or which at least positively influence the crystal growth of the phosphate layer, the phosphating baths generally also contain sodium, potassium, and / or ammonium ions to adjust the free acid. The term "free acid" is well known to those skilled in the art of phosphating. The method chosen to determine the free acid as well as the total acid in this step is specified in the examples. The free acid and the total acid represent an important control parameter for the phosphating baths, since they have a great influence on the coating weight. Free acid values between 0 and 1.5 points in phosphating in parts, or until 2. 5 points in coil phosphating, and total fat values of between approximately 10, or in the case of immersion phosphatization preferably approximately 15, and approximately 30 points are within the technically normal range and are suitable within the scope of this invention. For the phosphating of zinc surfaces it is not absolutely necessary that the phosphating baths contain what are known as accelerators. In the case of the phosphating of steel surfaces, however, it is necessary that the phosphating solution contains one or more accelerators. Such accelerators are conventionally employed in the prior art as components of zinc phosphating baths. The term accelerators refers to substances that chemically react with the hydrogen produced on the metal surface by the action of chemical attack of the acid in such a way that they are reduced themselves. Oxidation accelerators also have the effect of oxidizing iron (II) ions released by the action of chemical attack on steel surfaces to the state of trivalent oxidation, in such a way that they can precipitate as iron (III) phosphate. In step (II), solutions according to the prior art can be used to produce a conversion layer in aluminum. However, these solutions should not excessively dissolve the crystalline zinc phosphate layer formed in step (I). The pH of these solutions must therefore be within the range of 2.5 to 10, preferably from 3.3 to 10. Advantageously in step (II), solutions are chosen that contain components that additionally passivate the crystalline zinc phosphate layers. Such solutions are mentioned below by way of examples. Within the scope of the sequence of processes according to the invention, in step (II) the metal structures are generally contacted with the treatment solutions by spraying or immersion. The temperature of the treatment solution for step (II) is preferably chosen within the range of 20 to 70 ° C. By way of example, in step (II) a treatment solution having a pH within a range of about 5 to about 5.5 and containing generally about 0.3 to about 1.5 g / 1 of hexafluorotitanate ions and / or can be employed. hexafluorozirconate. It may be beneficial for the production against corrosion of the crystalline zinc phosphate layer produced in step (I) that this treatment solution additionally contains from about 0.001 to 0.1 g / 1 of copper ions for step (II). In addition, a treatment solution having a pH in the range of 3.5 to 5.8 and containing from 10 to 500 mg / l of organic polymers selected from poly-4-vinylphenol compounds of the following general formula (I): - (CH-CH2) "- where n is an integer between 5 and 100, each of X and Y independently of each other refers to hydrogen or a portion CRRx0H wherein each of R and R1 independently of each other, is hydrogen or an aliphatic portion or well aromatic with 1 to 12 carbon atoms. For step (II) in particular, treatment solutions containing polyvinylphenol derivatives are preferred in accordance with the teachings of EP-B-319 016. This document also presents the preparation of such polyvinylphenol derivatives. Therefore, in step (II), a treatment solution having a pH in the range of 3.3 to 5.8 and containing from 10 to 5000 mg / l of organic polymers selected from homopolymer or copolymer compounds containing amino groups, is preferably employed. comprise at least one polymer selected from the group consisting of (alpha) and (ß) materials, where: (alpha) consists of polymer molecules each having at least one unit corresponding to the following general formula (II) ): where: - each of R2 to R4 is independently selected from and independently of one molecule of the compound to another and from one unit to another of any polymer molecule according to this formula where there is more than one unit of this type in a single polymer molecule, within the group consisting of a hydrogen portion, an alkyl portion with 1 to 5 carbon atoms, and an aryl portion with 6 to 18 carbon atoms; - each of Y1 to Y4 is selected, independently of each other and independently of one molecule from the component to another and from one unit to another of any polymer molecule corresponding to this formula when there is more than one unit of this type in a molecule of single polymer, except in accordance with that indicated further below, within the group consisting of: a hydrogen portion; a -CH2C1 portion; an alkyl portion with 1 to 18 carbon atoms; an aryl portion with 6 to 18 carbon atoms; a portion corresponding to the general formula -CR12R13OR14, wherein each of R12 to R14 are selected from the group consisting of a hydrogen portion, an alkyl portion, an aryl portion, a hydroxyalkyl portion, an aminoalkyl portion, a mercaptoalkyl portion, and a phosphoalkyl portion; and a Z portion corresponding to one of the following two general formulas: where each of R5 to R8 is selected, independently from each other and independently of one molecule from the component to another and from one unit to another of any polymer molecule that complies with this formula when there is more than one unit of this type in a molecule single polymer, within the group consisting of the hydrogen portion, an alkyl portion, an aryl portion, a hydroxyalkyl portion, an aminoalkyl portion, a mercaptoalkyl portion, and a phosphoalkyl portion and R9 is selected from the group consisting of a portion hydrogen, an alkyl portion, an aryl portion, a hydroxyalkyl or polyhydroxyalkyl portion, an aminoalkyl or polyaminoalkyl portion, a mercaptoalkyl or poly-ercaptoalkyl portion, a phosphoalkyl or polyphosphoalkyl portion, an -O "portion, and an -OH portion, at least one from Y1 to Y4 in at least one unit of each selected polymer molecule is a Z-portion in accordance with or defined above, and - W1 is selected, independently of one molecule from the component to another and from one unit to another of any polymer molecule corresponding to the formula when there is more than one unit of this type in a single polymer molecule, within the group consisting of a hydrogen portion, an acyl portion, an acetyl portion, a benzyl portion; a 3-allyloxy-2-hydroxypropyl portion; a 3-benzyloxy-2-hydroxypropyl portion; a 3-alkyloxy-2-hydroxypropyl portion; a 2-hydroxyoctyl portion; a 2-hydroxyalkyl portion; a 2-hydroxy-2-phenylethyl moiety; a 2-hydroxy-2-alkylphenylethyl moiety; a benzyl, methyl, ethyl, propyl, unsubstituted alkyl, unsubstituted allyl, unsubstituted alkylbenzyl moiety; a halo or polyhaloalkyl portion, or halo or polyhaloalkyl. a portion derived from a condensation polymerization product of ethylene oxide, propylene oxide, or a mixture thereof by removal of a hydrogen atom therefrom; a portion of sodium, potassium, lithium, ammonium or substituted ammonium cation, or substituted phosphonium or phosphonium; and (ß) consists of polymer molecules each of which does not include a unit corresponding to the general formula (II) indicated above but does include at least one unit corresponding to the following general formula (III): where: - each of R, 10 and R "is selected, independently of each other, and independently of one molecule from the component to another and from one unit to another of any polymer molecule that meets this formula where there is more than one unit of this type in a single polymer molecule, within the group consisting of a hydrogen portion, an alkyl portion with 1 to 5 carbon atoms, and an aryl portion with 6 to 18 carbon atoms; each of Y4 to Y6 is selected, independently from each other and independently of one molecule from the component to another and from one unit to another of any polymer molecule corresponding to this formula when there is more than one unit of this type in a molecule of single polymer, except as further indicated below, within the group consisting of: a hydrogen portion, a -CH2C1 portion; an alkyl portion having 1 to 18 carbon atoms; an aryl portion with 6 to 18 carbon atoms; a portion corresponding to the general formula -CR12R13OR14, wherein each of R12 to R14 is selected from the group consisting of a hydrogen portion, an alkyl portion, an aryl portion, a hydroxyalkyl portion, an aminoalkyl portion, a mercaptoalkyl portion, and a phosphoalkyl portion; and a portion; and a Z-portion according to that defined for the material (alpha) above, at least one of Y1 to Y4 in at least one unit of each selected polymer molecule is a Z-portion according to that defined above; and - W is independently selected from one molecule of the component to another and from one unit to another of any polymer molecule corresponding to this formula when there is more than one unit of this type in a single polymer molecule, within the group that it consists of a hydrogen portion, an acetyl portion, a benzoyl portion; a 3-allyloxy-2-hydroxypropyl portion; a 3-benzyloxy-2-hydroxypropyl portion; a 3-butoxy-2-hydroxypropyl portion; a 3-alkyloxy-2-hydroxypropyl portion; a 2-hydroxyoctyl portion; a 2-hydroxyalkyl portion; a 2-hydroxy-2-phenylethyl moiety; a 2-hydroxy-2-alkylphenylethyl moiety; a benzyl, methyl, ethyl, propyl, unsubstituted alkyl, unsubstituted allyl, unsubstituted alkylbenzyl moiety; a haloalkyl or polyhaloalkyl portion, or a haloalkenyl or polyhaloalkenyl portion; a portion derived from a condensation polymerization product of ethylene oxide, propylene oxide or a mixture thereof by removal of a hydrogen atom therefrom; a portion of sodium, potassium, lithium, ammonium or substituted ammonium cation, or substituted phosphonium or phosphonium; the expression "polymer molecule" in the aforementioned definitions of materials (alpha) and (ß) includes any electrically neutral molecule with a molecular weight of at least 300 daltons.

Usually, primarily for reasons of economy, it is preferred to use as materials (alpha) and / or (ß) predominantly molecules that consist entirely, except in the case of relatively short end groups, of units that conform to one of the general formulas (I) and (II) in accordance with what is described above. Again, primarily, for reasons of economy, such materials are generally prepared by the reaction of homopolymers of p-vinylphenol, for the material (alpha), or condensation products of phenol-aldehyde, for the material (ß), with formaldehyde and secondary amines to graft the Z-portions into some of the activated benzene rings in materials that reacted in this way. However, in some particular cases, it may be more useful to employ chemically more complex types of materials (alpha) and / or (ß). For example, molecules formed by the reaction of a condensable form of a molecule belonging to the component (alpha) or (ß) according to the definition above, except that the molecule that reacted does not initially require to fulfill the requirement for the component (alpha) or (ß) in the sense that each molecule contains at least one Z-portion, with at least one other type of molecule selected from the group consisting of phenols, tannins, novolak resins, lignin compounds, aldehydes, ketones, and mixtures thereof, for the purpose of preparing a condensation reaction product which optionally, if required, is further reacted with (1) an aldehyde or ketone and (2) a secondary amine to introduce at least a portion Z according to what is defined above to each molecule, in such a way that the molecule can qualify as material (alpha) or (ß). Another example of more complex materials that can be used as material (alpha) is a material in which the polymer chains are at least predominantly copolymers of simple or substituted 4-vinylphenol with another vinyl monomer such as acrylonitrile, methacrylonitrile, acrylate of methyl, methyl methacrylate, vinyl acetate, vinyl methyl ketone, isopropenyl methyl ketone, acrylic acid, methacrylic acid, acrylamide, methacrylamide, n-amyl methacrylate, styrene, m-bromostyrene, p-bromostyrene, pyridine, diallyl ethylammonium salts, 1, 3-butadiene, n-butyl acrylate, t-butylaminoethyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, n-butyl vinyl ether, t-butyl vinyl ether, m-chlorostyrene, or- chlorostyrene, β-chlorostyrene, n-decyl methacrylate, N, N-diallylamine, N, N-di-n-butylacrylamide, di-n-butyl itaconate, di-n-butyl maleate, diethylaminoethyl methacrylate, monovinyl ether of diethylene glycol , diethyl fumarate, diethyl itaconate, diethylvinyl phosphate, vinylphosphonic acid, diisobutyl maleate, diisopropyl itaconate, diisopropyl maleate, dimethyl fumarate, dimethyl itaconate, dimethyl maleate, di-n-nonyl fumarate, maleate di-n-nonyl, dioctyl fumarate, di-n-octyl itaconate, di-n-propyl itaconate, N-dodecyl vinyl ether, ethyl fumarate acid, ethyl maleate acid, ethyl acrylate, ethyl cinnamate , N-ethyl methacrylamide, ethyl methacrylate, ethyl vinyl ether, 5-ethyl-2-vinylpyridine, 5-ethyl-2-vinylpyridine-1-oxide, glycidyl acrylate, glycidyl methacrylate, n-hexyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, isobutyl methacrylate, isobutyl vinyl ether, isoprene, isopropyl methacrylate, isopropyl vinyl ether, itaconic acid, lauryl methacrylate, methacrylamide, methacrylic acid, methacrylonitrile, N-methylolacrylamide, N-methylol -methacrylamide, N-isobutoxymethylacrylamide, N-isobutoxy-methyl methacrylamide, N-alkyloxymethylacrylamide, N-alkyl-oxymethylmethacrylamide, N-vinylcaprolactam, methyl acrylate, N-methylmethacrylamide, alpha-methylstyrene, m-methylstyrene, o-methylstyrene, jD-methylstyrene, 2-methyl-5-vinylpyridine, n-propyl methacrylate, sodium p_-styrenesulfonate, stearyl methacrylate, styrene, p-styrenesulfonic acid, p-styrenesulfonamide, bromide vinyl, 9-vinylcarbazole, vinyl chloride, vinylidene chloride, 1-vinylnaphthalene, 2-vinylnaphthalene, 2-vinylpyridine, 4-vinylpyridine, 2-vinylpyridine N-oxide, 4-vinylpyrimidine, and N-vinylpyrrolidone. The following preferences, primarily for reasons of economy, improved resistance to corrosion, and / or increased solubility in water, apply, independently of each preference, to the material molecules (alpha) and (ß): each of R2 to R6, R10, R11, W1, and W2, independently of each other and independently between units in the same molecule or in a different molecule, is preferably a hydrogen portion; - each of Y1 to Y6, independently of each other and independently between units in the same molecule or in a different molecule, preferably represents a hydrogen or a Z portion; - each polymer molecule contains a number of units corresponding to one of the general formulas (II) and (III) according to what is defined above which is at least, with increasing preference in the following order, 2, 3, 4, 5, 6, 7, or 8 and independently of preference is not greater than 100, 75, 50, 40, 30, or 20, in the total of materials (alpha) and (ß) in a composition used in step (II) According to the invention, the number of portions Z has a ratio in relation to the number of aromatic nuclei that is at least, with increasing preference in the given order, 0.01: 1.0, 0.03: 1.0, 0.05: 1.0, 0.10: 1.0, 0.20: 1.0, 0.40: 1.0, 0.50: 1.0, 0.60: 1.0, 0.70: 1.0, 0.80: 1.0, 0.90: 1.0, or 0.95: 1.0 and preferably, independently, it's just, preferably increasing in the given order, 2.0: 1.0, 1.6: 1.0, 1.50: 1.0, 1.40: 1.0, 1.30: 1.0, 1.20: 1.0, 1.10: 1.0, or 1.00: 1.0; and - in the total of the materials (alpha) and (ß) in a composition used in step (II) according to the invention, the number of "polyhydroxy portions Z", which are defined as portions in which at least one of R5 to R8 in the general formulas given above for the Z portions has (i) from 3 to 8, or preferably from 4 to 6 carbon atoms, and (ii) so many hydroxyl groups, each bonded to one of the atoms carbon, which one less than the number of carbon atoms in the portion R5 to R8, has a ratio relative to the total number of Z portions in the composition which is at least, preferably increasing in the given order, 0.10: 1.0 , 0.20: 1.0, 0.30: 1.0, 0.40: 1.0, 0.50: 1.0, 0.60: 1.0, 0.70: 1.0, 0.80: 1.0, 0.90: 1.0, or 0.98: 1.0 (preparation of materials of this type is described in references mentioned above). Poly (5-vinyl-2-hydroxy-N-benzyl) -N-methylglucamine is a specific polymer of the most preferred type which, in the range of acidic pH to be established, is present at least in part as a salt of ammonium. Solutions can be employed which do not contain additional active constituents, apart from the polyvinylphenol derivative and an acid for adjusting the pH, preferably phosphoric acid. Additions of additional active constituents, particularly hexafluorotitanate or hexafluorozirconate ions, can, however, improve the formation of aluminum layer. For example, a solution can be used whose pH is preferably in the range from about 3.3 to about 5.8 and which contains as organic polymer from about 100 to about 5000 mg / L of an organic polymer in the form of a methylethanolamine derivative or derivative of N-methylglucamine or polyvinylphenol and in addition of 10 to 2000 mg / l of phosphate ions, 10 to 2500 mg / l of hexafluorotitanato ions or hexafluorozirconate, and 10 to 1000 mg / l of manganese ions. Instead of the polyvinylphenol derivatives whose preparation requires a certain expense, solutions or dispersions of organic polymers selected from homopolymers and / or copolymers of acrylic acid and methacrylic acid and their esters can be used in step (II). Preferably, these solutions or dispersions have pH values within a range from about 3.3 to about 4.8 and contain from about 250 to about 1500 mg / l of organic polymers. In accordance with the teachings of EP-B-0 08 942, these polymer solutions or dispersions may also contain hexafluorotitanatos, hexafluorozirconates and / or hexafluorosilicates. EXAMPLES A process sequence in accordance with the present invention was tested on cold rolled steel sample metal sheets (usually abbreviated here as "CRS"), electrolytically galvanized steel (here abbreviated usually as "ZE"), steel with iron-zinc electrolytic coating (usually abbreviated here as "ZFE") and aluminum 6111. As is conventional in the automotive manufacturing sector, these metal sheets were first cleaned with an alkaline solution and activated with a activation solution containing titanium phosphate. The sheets were then immersed for 3 minutes in a phosphating bath at a temperature of 48 ° C having the following composition: Zn = 1.2 g / 1 Mn = 0.8 g / 1 Ni = 0.8 g / 1 PO, f 18 g / 1 N02 = 110 ppm Residual Cations = Na + Free Acid 1.1 Sealed phosphate layers with coating weights of the order of g / m2 were deposited by this phosphating process in cold rolled steel, electrolytically galvanized steel and zinc plated steel. -iron. Photographs of electron microscopy showed that only very scattered zinc phosphate crystals were formed in the aluminum sheets. In step (II) the sample sheets were treated with fully deionized water (comparison tests) as well as with solutions of one of the following compositions (a), (b), and (c). These solutions had a temperature of 25 ° C and were sprayed for 30 seconds on the sample sheets. These sheets were then sprayed for 15 seconds with fully deionized water and blown dry with compressed air at room temperature. For the corrosion prevention tests, these sheets were coated with a triple barrier paint structure, applied in the order shown: E = PPG ED 5000 coating, base coat = Dupont white 542 AB 839, light coating = Dupont RK 8010 The corrosion resistance tests were carried out in accordance with the General Motors GM9540P-B process cycle, which consists of the following steps: 1. (1.1) spray each panel with a salt spray solution ( 0.9% by weight of table salt, 0.1% by weight of calcium chloride, 0.25% by weight of sodium bicarbonate, the rest of water) sufficiently to completely wet the panel; (1.2) within 30 minutes after spraying the panel is placed in a controlled atmosphere to maintain a temperature of 25 ° C and a relative atmospheric humidity of 30 to 50%; (1.3) ninety minutes after the start of step (1.2), remove the panel from the controlled atmosphere in which it was maintained during step (1.2), and then repeat steps (1.1) and (1.2) three times each one. Step 1 globally therefore requires 8 hours. 2. a condensate water test of 8 hours at a temperature of 49 ° C and a relative atmospheric humidity of 95 to 100%; 3. a dry storage of 8 hours at a temperature of 60 ° C and under a relative atmospheric humidity of less than 30%; 4. during the weekend, only dry storage at a temperature of 25 ° C and with a relative atmospheric humidity of 30 to 50%. Steps 1 to 3 above in each case form a cycle that is repeated from Monday to Friday. Step 4 is not counted in the cycle number. The tests of a duration of 40 cycles (5 cycles per week corresponding to a test time of 8 weeks).

Table 1 below shows the compositions of the three subsequent rinsing solutions, and tables 2 and 3 show the amounts of chemical attack of zinc phosphate coating and average paint runs on the brand (full brand width) respectively . Table 1: POSTERIOR RINSING COMPOSITIONS Ingredient Amount of ingredient in: rinse solution solution after rinsing after rinsing (a) terior (b), terior (c), pH 2.7 pH 3.5 pH 2.9 polymer * 0.453 g / 1 0.451 g / 1 0.113 g / 1 phosphate 0.957 g / 1 0.955 g / 1 0.239 g / 1 hexafluorotite- 1 g / 1 1 g / l 0.25 g / 1 born Mn (II) 0.39 g / 1 0.39 g / 1 0.1 g / 1 * Poly (5-vinyl-2-hydroxy-N-benzyl) -N-methylglucamine Table 2: VALUES OF LOSS BY CHEMICAL ATTACK OF ZINC PHOSPHATE COATING Test No. substrate solution of rinse loss after coating percentage example 1 CRS (a) 69 example 2 CRS (b) 5 e emplo 3 CRS (c) 27 example 4 ZE (a) 50 example 5 ZE (b) 5 example 6 ZE (c) 31 example 7 ZFE (a) 50 eg 8 ZFE (b) 1 example 9 ZFE (c) 25 Table 3: CORROSION TEST RESULTS No. Test substrate substrate rinsing rinse paint, pos > terior millimeters Ex. of comp .1 CRS deionized water 9.6 example 1 CRS (a) 8.8 example 2 CRS (b) 3.1 example 3 CRS (c) 4.2 Ex. of comp.2 ZE deionized water 2.2 example 4 ZE (a) 1.6 example 5 ZE (b) 1.8 example 6 ZE (c) 1.8 Ex. of comp .3 ZFE deionized water 2.2 example 7 ZFE (a) 1.3 example 8 ZFE (b) 1.6 example 9 ZFE (c) 1.1 Ex. of comp .4 A16111 deionized water 1.7 example 10 Al 6111 (a) 0.9 example 11 A16111 (b) 1.2 example 12 A16111 (c) 1.2

Claims (5)

1. CLAIMS l. A process for the chemical pre-treatment, before the application of an organic coating, of a composite metal structure containing at least one portion of aluminum or aluminum alloy together with at least one portion of steel, galvanized steel, or galvanized steel alloyed, said process comprises the steps of:
2. (I) treat in a first step the composite metal structure with a zinc phosphating solution which forms in the steel and in the galvanized steel and / or alloyed galvanized steel a layer of crystalline zinc phosphate that covers the surface, which has a coating weight within a range of 0.5 to 5 g / m2, but without forming a layer of zinc phosphate in the aluminum portions; and subsequently, with or without intermediate rinse with water, (II) to contact, in a second step, the composite metal structure with a treatment solution that does not dissolve more than 60% of the crystalline zinc phosphate layer in steel , galvanized steel, and / or alloyed galvanized steel, but produces a conversion layer in the aluminum portions. . A process according to claim 1, wherein: in step (I) the zinc phosphating solution has a pH within a range of 2.5 to 3.6 and a temperature within a range of 20 to 65 ° C and contains a amount of free fluoride, expressed in g / 1, which is not greater than a quotient of number 8 divided by the solution temperature in ° C; and in step (II) the treatment solution does not dissolve more than 25% of the crystalline zinc phosphate layer deposited in step (I). A process according to claim 2, wherein: the zinc phosphating solution used in step (I) comprises: - from 0.3 to 3 g / 1 of Zn (II), - from 5 to 40 g / 1 of phosphate ions, and at least one of the following amounts of the following types of accelerators: - from 0.3 to 4 g / 1 of chlorate ions, - from 0.01 to 0.2 g / 1 of nitrite ions, - from 0.05 to 2 g / 1 of m-nitrobenzenesulfonate ions, - from 0.05 to 2 g / l of m-nitrobenzoate ions, - from 0.05 to 2 g / l of p-nitrophenol, - from 0.001 to 0.15 g / l of hydrogen peroxide in free form or bound, - from 0.1 to 10 g / 1 of hydroxylamine in free or bound form,
3. Y - from 0.1 to 10 g / 1 of a reducing sugar; and in step (II) the treatment solution does not dissolve more than 10% of the crystalline zinc phosphate layer deposited in step (I). A process according to claim 3, wherein the zinc phosphating solution employed in step (I) further comprises one or more of the following amounts of cations: - from 0.001 to 4 g / 1 manganese (II); - from 0.001 to 4 g / 1 of nickel (II), - from 0.002 to 0.2 g / 1 of copper (II), - from 0.2 to 2.5 g / 1 of magnesium (II), - from 0.2 to 2.5 g / 1 of calcium (II), - from 0.01 to 0.5 g / 1 of iron (II), - from 0.2 to 1.5 g / 1 of lithium (I), and - from 0.02 to 0.8 g / 1 of tungsten (VI). A process according to any of claims 1 to 4, wherein the treatment solution employed in step (II) has a pH within a range of 3.5 to 5.5 and comprises 0.3 to 1.5 g / 1 of hexafluorotitanate ions, ions hexafluorozirconate, or both. A process according to claim 5, wherein the treatment solution employed in step (II) further comprises 0.01 to 0.1 g / 1 of copper ions. A process according to any of claims 1 to 4, wherein the treatment solution employed in step (II) has a pH within a range of 3.5 to 5.8 and contains from 10 to 500 mg / l of organic polymers selected from poly-4-vinylphenol molecules corresponding to the following general formula (I):
4. ~ (CH-CH2) n- where n is an integer between 5 and 100, each of X and Y, independently of each other, indicates hydrogen or a CRR-OH portion wherein each of R and R1 independently is hydrogen or an aliphatic or aromatic moiety with 1 to 12 carbon atoms. A process according to any of claims 1 to 4, wherein the treatment solution employed in step (II) has a pH within a range of 3.3 to 5.8 and contains from 10 to 5000 mg / l of selected organic polymers within of the materials (alpha) and (ß), where: (alpha) consists of polymer molecules each of which has at least one unit corresponding to the following general formula (II): where: - - each of Rz to R4 is independently selected from and independently of one molecule of the compound to another and from one unit to another of any polymer molecule in accordance with this formula where there is more than one unit of this type in a single polymer molecule, within the group consisting of a hydrogen portion, an alkyl portion with 1 to 5 carbon atoms, and an aryl portion with 6 to 18 carbon atoms; - each of Y1 to Y4 is selected, independently of each other and independently of one molecule from the component to another and from one unit to another of any polymer molecule corresponding to this formula when there is more than one unit of this type in a molecule of single polymer, except in accordance with that indicated further below, within the group consisting of: a hydrogen portion; a -CH2C1 portion; an alkyl portion with 1 to 18 carbon atoms; an aryl portion with 6 to 18 carbon atoms; a portion corresponding to the general formula -CR12R130R14, wherein each of R12 to R14 are selected from the group consisting of a hydrogen portion, an alkyl portion, an aryl portion, a hydroxyalkyl portion, an aminoalkyl portion, a mercaptoalkyl portion, and a phosphoalkyl portion; and a Z portion corresponding to one of the following two general formulas: where each of R to R is selected, independently from each other and independently from one molecule of the component to another and from one unit to another of any polymer molecule that complies with this formula when there is more than one unit of this type in a molecule single polymer, within the group consisting of the hydrogen portion, an alkyl portion, an aryl portion, a hydroxyalkyl portion, an aminoalkyl portion, a mercaptoalkyl portion, and a phosphsalkyl portion and R9 is selected from the group consisting of a portion hydrogen, an alkyl portion, an aryl portion, a hydroxyalkyl or polyhydroxyalkyl portion, an aminoalkyl or polyalkanoalkyl portion, a mercaptoalkyl or a polymercaptoalkyl portion, a phosphoalkyl or polyphosphoalkyl portion, a -0"portion, and an -OH portion, at least one from Y1 to Y4 in at least one unit of each selected polymer molecule is a Z-portion in accordance with defined above, and - W1 is selected, independently of one molecule from the component to another and from one unit to another of any polymer molecule corresponding to the formula when there is more than one unit of this type in a single polymer molecule, within of the group consisting of a hydrogen portion, an acyl portion, an acetyl portion, a benzyl portion; a 3-allyloxy-2-hydroxypropyl portion; a 3-benzyloxy-2-hydroxypropyl portion; a 3-alkyloxy-2-hydroxypropyl portion; a 2-hydroxyoctyl portion; a 2-hydroxyalkyl portion; a 2-hydroxy-2-phenylethyl moiety; a 2-hydroxy-2-alkylphenylethyl moiety; a benzyl, methyl, ethyl, propyl, unsubstituted alkyl, unsubstituted allyl, unsubstituted alkylbenzyl moiety; a halo or polyhaloalkyl, or halo or polyhaloalkenyl portion; a portion derived from a condensation polymerization product of ethylene oxide, propylene oxide, or a mixture thereof by removal of a hydrogen atom therefrom; a portion of sodium, potassium, lithium, ammonium or substituted ammonium cation, or substituted phosphonium or phosphonium; and (ß) consists of polymer molecules each of which does not include a unit corresponding to the general formula (II) indicated above but does include at least one unit corresponding to the following general formula (III): where: - each of R10 and R11 is independently selected from independently of one molecule from one component to another and from one unit to another of any polymer molecule that complies with this formula where there is more than one unit of this type in a single polymer molecule, within the group consisting of a hydrogen portion, an alkyl portion with 1 to 5 carbon atoms, and an aryl portion with 6 to 18 carbon atoms; - each of Y4 to Y6 is selected, independently of each other and independently of one molecule from the component to another and from one unit to another of any polymer molecule corresponding to this formula when there is more than one unit of this type in a molecule single polymer, except as further indicated below, within the group consisting of: a hydrogen portion, a -CH2C1 portion; an alkyl portion having 1 to 18 carbon atoms; an aryl portion with 6 to 18 carbon atoms; a portion corresponding to the general formula -CR12R13OR14, wherein each of R12 to R14 is selected from the group consisting of a hydrogen portion, an alkyl portion, an aryl portion, a hydroxyalkyl portion, an aminoalkyl portion, a mercaptoalkyl portion, and a phosphoalkyl portion; and a portion; and a Z-portion according to that defined for the material (alpha) above, at least one of Y1 to Y4 in at least one unit of each selected polymer molecule is a Z-portion according to that defined above; and - W2 is selected, independently of one molecule from the component to another and from one unit to another of any polymer molecule corresponding to this formula when there is more than one unit of this type in a single polymer molecule, within the group that it consists of a hydrogen portion, an acetyl portion, a benzoyl portion; a 3-allyloxy-2-hydroxypropyl portion; a 3-benzyloxy-2-hydroxypropyl portion; a 3-butoxy-2-hydroxypropyl portion; a 3-alkyloxy-2-hydroxypropyl portion; a 2-hydroxyoctyl portion; a 2-hydroxyalkyl portion; a 2-hydroxy-2-phenylethyl moiety; a 2-hydroxy-2-alkylphenylethyl moiety; a benzyl, methyl, ethyl, propyl, unsubstituted alkyl, unsubstituted allyl, unsubstituted alkylbenzyl moiety; a haloalkyl or polyhaloalkyl portion, or a haloalkenyl or polyhaloalkenyl portion; a portion derived from a condensation polymerization product of ethylene oxide, propylene oxide or a mixture thereof by removal of a hydrogen atom therefrom; a portion of sodium, potassium, lithium, ammonium or substituted ammonium cation, or substituted phosphonium or phosphonium; the expression "polymer molecule" in the aforementioned definitions of materials (alpha) and (ß) includes any electrically neutral molecule with a molecular weight of at least 300 daltons. 9. A process according to claim 8, wherein at least 20% by number of the Z portions in the material (alpha) and the material (ß) in the treatment solution employed in step (II) of the process are portions Polyhydroxyl Z A process according to claim 8, wherein the solution in treatment employed in step (II) of the process comprises, as a material (alpha) a condensation reaction process of (i) polyvinylphenol having an average molecular weight by weight within a range of 1000 to 10,000, (ii) formaldehyde or paraformaldehyde, and (iii) at least one secondary organic amine. 11. A process according to claim 10, wherein the secondary organic amine is selected from the group consisting of methylethanolamine, N-methylglucamine, and mixtures thereof. 12. A process according to claim 11, wherein the treatment solution having a pH within a range of 3.3 to 4.8, contains from 100 to 5000 mg / l of the condensation reaction product, and further comprises: - from 10 to 2000 mg / l of phosphate ions; - from 10 to 2500 mg / l of hexafluorotitanate ions, hexafluorozirconate ions, or both; from 10 to 1000 mg / l of manganese ions. . A process according to one or more of claims 1 to 4, wherein the treatment solution employed in step (II) has a pH within a range of 3.3 to
5. 5.8, and comprises 250 to 1500 mg / l of polymers organic compounds selected from the group consisting of homopolymers and copolymers of acrylic acid, methacrylic acid, and esters of acrylic and methacrylic acids.