MXPA98002943A - Composition and coating process by conversion of finally crystalline phosphate, and / or rap - Google Patents

Abstract

A combination of difunctional organic acid, preferably a hydroxy acid such as citric acid, or a salt thereof with acrylic acid / acrylate polymers in the liquid forming compositions of the zinc phosphate conversion coating also preferably containing hydroxylamine, results in the refining the size of the glass in the formed coating and / or the faster formation of a conversion coating thick enough to protect against the subsequent oxidation of a ferro substrate

Description

"COMPOSITION AND COATING PROCESS BY CONVERSION OF FINALLY CRYSTALLINE PHOSPHATE, AND / OR QUICKLY" BACKGROUND OF THE INVENTION FIELD OF THE INVENTION This invention relates to compositions and processes for depositing conversion coatings containing zinc phosphate on metal surfaces, particularly the surfaces of iron, steel, zinc-iron alloy, galvanized steel and other predominantly zinciferous surfaces, and aluminum and its alloys. which contain at least 45 weight percent aluminum. The invention relates particularly to these compositions and processes which produce, at a high coating speed, a conversion coating with a very fine average crystal size.

DECLARATION OF THE RELATED TECHNIQUE The general process of the zinc phosphate conversion coating is well known in the art. See, v.gr., by M. Hamacher, "Ecologically Safe Pretreat ents of Metal Surfaces ", Henkel-Reférate 30 (1994), pages 138 to 143, which, except to the extent that it may be contrary to any explicit statement herein, is incorporated herein by reference. contact of the active metals with aqueous acidic compositions containing zinc and phosphate ions results in the deposition on the active metal surfaces of a conversion coating containing zinc phosphate.If the active metal is ferrous, the phosphates of Iron is usually included in the coating, and nickel and / or manganese of modern practice are often included in the coating composition and thus in the coating formed in order to accelerate the process and improve the coating uniformity, It is customary to include in the coating composition a component called an "accelerator" that is not usually incorporated into the formed coating. Typical widely used include nitrate, nitrite and chlorate ions, water-soluble organic nitroaromatic compounds such as p-nitrobenzenesulfonic acid and hydroxylamine (the latter is almost always the form of salts or complexes). A problem frequently observed with the prior art conversion coatings, particularly on cold rolled steel, has been the production of small rust areas on the metal areas of the treated substrate that were blocked from full contact with the liquid forming composition of the conversion coating by small gas bubbles which formed and / or were trapped on the surface of the substrate during the conversion coating treatment process. It is believed that the water vapor within these bubbles is sufficient to cause rust before the desired formation that a protective conversion coating can advance sufficiently to prevent rusting, and once the rust zone has formed, no it can be satisfactorily covered later even by complete contact with the liquid forming composition of the conversion coating.

DESCRIPTION OF THE INVENTION OBJECT OF THE INVENTION It is an object of this invention to provide a phosphating composition and process that provides a protective conversion coating with a more refined crystal size than is now generally achieved by zinc phosphating. Another alternative or simultaneous object is to provide a zinc phosphating composition and process that will form a high quality protective conversion coating over a short contact time period with a metal substrate to be coated such that the coil coating and other continuous phosphating operations can be operated at higher speeds. Still another simultaneous or alternative object prevents the formation of surface rust in small areas of the total substrate, which are blocked by gas bubbles of complete contact with the conversion coating solution. Other objects will become evident from the description that will be given below.

GENERAL PRINCIPLES OF DESCRIPTION Except for the claims and examples of operation, with any other site expressly indicated, all numerical quantities of this description indicating quantities of material or conditions of reaction and / or use must be understood as being modified by the word "approximately" for describe the broader scope of the invention. Practice within stated numerical limits, however, is usually preferred.

Also, through the description and the claims, unless expressly stated otherwise: the percentage values "parts of" and ratio are by weight; the description of a group or class of materials as appropriate or preferred for a particular object in relation to the invention implies that the mixtures of any two or more of the members of the group or class are equally appropriate or preferred; the description of the constituents in chemical terms refers to the constituents in time of addition to any combination specified in the description, and does not necessarily prevent chemical interactions between the constituents of a mixture once it has been mixed; the specification of materials in ionic form implies the presence of sufficient counterions to produce electrical neutrality for the composition with a set; any of the counterions therefore implicitly specified may preferably be selected from among the other constituents explicitly specified in ionic form, to the greatest extent possible, otherwise these counterions may be freely selected except that counterions acting detrimentally to the objects of the invention are avoided. the invention; the terms "molecule" and "mol" and their grammatical variations can be applied to ionic, elementary entities or any other type of chemical entities defined by the number of atoms of each type present in it, as well as substances with well-defined neutral molecules; the first definition of an acronym or other abbreviation applies to all subsequent uses in the present abbreviation; and the term "polymer" includes "oligomer," "homopolymer," "copolymer," "terpolymer," and the like.

COMPENDIUM OF THE INVENTION It has been found that one or more of the objects previously disclosed for the invention can be achieved by the use of an aqueous liquid conversion coating forming composition comprising, preferably, essentially consisting of or of higher preference consisting of water and: ( A) dissolved zinc cations; (B) dissolved phosphate anions; (C) a dissolved component selected from the group consisting of organic acids and anions thereof which (i) contain at least two residues per molecule which are selected from the group consisting of carboxyl and carboxylate residues and hydroxyl residues which are not part of a carboxyl residue and (ii) do not contain more than 12 carbon atoms per molecule; and (D) a dissolved component selected from the group consisting of polymer molecules containing more than 12 carbon atoms per molecule and wherein at least 50 percent of the polymer molecule is composed of one or more residues with one of the formulas: CH3 I - (CH2-CH) - or - (CH2-C) -, II c = oc = or II OM OM wherein M represents a hydrogen atom, a monovalent cation or a monovalent fraction of a polyvalent cation; and, optionally, (E) a component of dissolved metal cations which are selected from the group consisting of metal cations excluding zinc cations, with a charge of at least two; (F) a component of dissolved accelerator molecules, excluding any of the molecules that are part of any of the above components; Y (G) a component of dissolved simple fluoride anions and / or complexes, excluding any of the anions that are part of any of the above co-pending.

Various embodiments of the invention include working compositions for direct use in the treatment of metals, replenishment concentrates of which these working compositions can be prepared by dilution with water, appropriate replenishment concentrates to maintain optimum performance of the working compositions of the invention. according to the invention, processes for treating metals with a composition according to the invention, and prolonged processes including additional steps which are conventional per se, such as cleaning, activation with soles of titanium phosphate (Jernstedt salts), rinsing and subsequent painting or a similar overcoating process that puts in place a protective coating containing the organic binder above the treated metal surface according to a more critical embodiment of the invention. Manufacturing articles including surfaces treated in accordance with a process of this invention are also within the scope of the invention.

DESCRIPTION OF THE PREFERRED MODALITIES Due to a variety of reasons, it is sometimes preferred that the compositions according to the invention as defined above should be essentially free of many ingredients used in the compositions for similar purposes in the prior art. Specifically, when the maximum storage stability of a concentrate is desired, it is preferably preferred to be increased in the order provided, independently for each component preferably reduced to the minimum indicated below, that these compositions contain no more than 25, 15, 9, 5, 3, 1.0, 0.35, 0.10, 0.08, 0.04, 0.02, 0.01, 0.001 or 0.0002 percent of each of the following constituents: organic compounds of nitrite, chlorate, chloride, bromide, iodide containing the groups of nitro, hexavalent chromium, manganese in a valence state of four or greater, ferricyanide; ferrocyanide; and pyrazole compounds. In contrast, in work solutions, accelerator components such as those included in this list do not have a known detrimental effect (except as regards the danger of staining zinciferous surfaces with compositions containing too much chloride, which is formed in situ by chlorate), but they are generally not needed, and their absence can therefore be preferred. For economical reasons .

The dissolved zinc cations required for the necessary component (A) can be obtained from any soluble zinc salt of the zinc metal itself or any zinc-containing compound that reacts with the aqueous acid to form dissolved zinc cations. The normally preferred sources, mainly due to economic reasons, are zinc oxide, zinc carbonate, and zinc dihydrogen phosphate. In an aqueous liquid working conversion coating forming composition forming the aqueous liquid composition according to the invention, the concentration of the dissolved zinc cations is preferably at least, preferably increased in the proportionate order of 0.1, 0.2. , 0.30, 0.40, 0.50, 0.60, 0.70, 0.80, 0.85, 0.90, 0.95, 0.98 or 1.00 part per thousand (which will be abbreviated as "ppt"), and preferably independently is not more than, preferably increased in the order provided 2.0, 1.8, 1.6, 1.4, 1.30, 1.20, 1.15 or 1.10 ppt. The dissolved phosphate ions that make up the necessary component (B) can also be obtained from a variety of sources as is known in the general phosphate conversion coating field. Due to a preference that will be observed below for a considerable amount of total acid of an aqueous liquid working conversion forming composition in accordance with the invention, it was usually an amount of the phosphate ion content preferably to be supplied by added phosphoric acid. to the composition, and the stoichiometric equivalent as phosphate ions of all the phosphoric acid, and not dissociated and all its anionic ionization products in solution, together with the stoichiometric equivalent as phosphate ions of any dihydrogen phosphate, monohydrogen phosphate, or ions of Fully neutrized phosphate added to the composition in salt form should be understood as forming part of the component (B), regardless of the current degree of ionization that exists in the composition. In an aqueous liquid working conversion coating forming composition according to the invention, the concentration of the component (B) is preferably at least, preferably increased in the order provided of 5, 6, 7, 8, 9, 10, 10.5, 11.0, 11.5, 11.9, 12.2, 12.4, 12.6, 12.8, 13.0, 13.2, 13.4 or 13.6 ppt and preferably independently is no more than, preferably increased in the proportioned order of 100, 50, 40, 30 , 27, 24, 21, 19, 18, 17, 16.5, 16.0, 15.5, 15.0, 14.5, 14.3, 14.1, 13.9 or 13.7 ppt. Independently of the other preferences, the ratio of the concentration of the component (A) to the concentration of the component (B) in an aqueous liquid composition for conversion coating forming according to the invention, whether working or concentrated, preference is at least, preferably increased in the order of 1.0: 50, 1.0: 40, 1.0: 35, 1.0: 30, 1.0: 27, 1.0: 24, 1.0: 21, 1.0: 18, 1.0: 16, 1.0: 15, 1.0: 14 or 1.0: 13.7 and preferably independently is no greater than, preferably increased in the order of 1.0: 5.0, 1.0: 6.0, 1.0: 7.0, 1.0: 8.0, 1.0: 8.5, 1.0: 9.0, 1.0: 9.5, 1.0: 10, 1.0: 10.5, 1.0: 11.0, 1.0: 11.5, 1.0: 12.0, 1.0: 12.5, 1.0: 13.0 or 1.0: 13.3. Component (C) is preferably derived from anions or other molecules each of which contains both at least one carboxy (ato) residue and a hydroxyl residue that is not part of any carboxyl (ato) residue, greater preference of the group consisting of citric acid, gluconic acid, heptogluconic acid, and the water-soluble salts of all these acids, most preferably of the citric acid and its water-soluble salts. Independently, the concentration of the component (C) in an aqueous liquid composition forming the working conversion coating according to the invention, of preference is at least preferably increased in the order provided of 0.1, 0.2, 0.3 or 0.4 millimol per kilogram of the total composition (hereinafter abbreviated usually as "mM / kg") and, if a small crystal size of the formed conversion coating is desired, is preferably at least, preferably increased in the proportioned order of 1.0, 1.2 or 1.6 mM / kg; if the small crystal size of the formed conversion coating is desired and the concentration of the component (D) is near the lower end of the preferred scales as will be described further below, the concentration of the component (C) in an aqueous liquid composition The working conversion coating former according to the invention is preferably still at least 3.5 mM / kg. Independently, mainly for reasons of economy, the concentration of the component (C) in a working composition according to the invention is preferably no greater than, preferably increased in the order provided 50, 25, 15, 10, 7, 5 , 4.5 or 4.1 mM / kg, and if acceptable in larger crystal size, more preferably is not greater than, preferably increased in the proportionate order of 3.2, 3.0, 2.8, 2.5, 2.2, 1.9, or 1.7 mM / kg. The component (D) is preferably selected from the polymer molecules wherein at least, preferably increased in the order provided, 60, 70, 75, 80, 85, 90 or 95 percent of the molecule consists of one or more residues with one of the formulas: CH3 I - (CH2-CH) - or - (CH2-C) -, IIC = 0 c = or II OM OM more preferred the formula shown on the left, in other words, acrylate residues instead of methacrylate residues. Independently, preferably increased in the order provided, at least 30, 50, 60, 70 or 80 percent of these acrylate and methacrylate residues in component (D) have hydrogen instead of any other atom or cation in the position in the formula indicated by the "M" symbol in the formulas shown. Regardless of any of the other preferences, the weight average molecular weight of the polymers in the component (D), which is measured as its stoichiometric equivalent when all the acrylate and methacrylate residues are in the form of an acid, is preferably at least, preferably increased in the order of 400, 500, 600, 700, 750, 800, 850, 900, 950 or 975 and independently preferably it is no more than, preferably increased in the proportionate order of 10,000, 9000, 8000, 7000, 6000, 5000, 4500, 4000, 3500, 3000, 2500, 2000, 1700, 1400, 1300, 1250, 1200, 1150, 1100 or 1050. Also independently of the other preferences for the component (D) , the concentration of the component (D) in a liquid, aqueous working conversion coating forming composition according to the invention is preferably at least 5, 10, 15, 20, 22 or 24 parts per million and independently of preferred way is n or greater than 300, 200, 100, 85, 75, 65 or 55 parts per million and, unless the concentration of component (C) is not greater than 0.4 mM / kg, more preferably is not greater than, with increased preference in the proportionate order of 45, 35, 30 or 26 parts per million. If desired, high corrosion resistance after the application of an organic protective coating to a metal substrate, subsequent to the formation of a conversion coating thereon by contacting the substrate with an aqueous liquid coating forming composition. The working conversion according to the invention is usually an aqueous liquid working conversion coating forming composition according to the invention which preferably contains one or more metal ions which are selected from the optional component (E). Examples of the preferred combinations of zinc ions with metal ions of component (E), in an aqueous liquid composition forming the working conversion coating according to the invention are: Zn and Mn; Zn, Mn, and Co; Zn, Mn, and Cu; Zn and Cu; Zn, Co, and Cu; and Zn, Mn, and Ni. It is especially preferred that an aqueous liquid composition forming the working conversion coating according to the invention contains, at least as part of the optional component (E), divalent manganese cations dissolved in a concentration which is preferably at least with increased preference in the proportionate order of 100, 200, 300, 400, 500, 550, 600, 650, 700, 750, 800, 825 or 835 parts per million, and independently of preference as mainly due to reasons of economy, is not greater than, preferably increased in the proportioned order of 4000, 3000, 2000, 1500, 1400, 1300, 1250, 1200, 1150, 1100, 1050, 1000, 950 or 900 parts per million. Furthermore, irrespective of the preferences for manganese as mentioned, it is especially preferred that an aqueous liquid working conversion coating forming composition in accordance with the invention includes, as at least part of the optional component (E), nickel cations divalent dissolved in a concentration which is preferably at least, preferably increased in the proportioned order of 100, 200, 300, 400, 500, 550, 600, 650, 700, 750, 765, 785 or 79O parts per million, and independently preferably, primarily for reasons of economy, it is no greater than, preferably increased in the order provided, of 4000, 3000, 2000, 1500, 1400, 1300, 1250, 1200, 1150, 1100, 1050, 1000, 950, 900 or 850 parts per million. Independently of the other preferences, the ratio of the concentration of the zinc cations to the sum of the concentrations of the manganese and nickel cations in an aqueous liquid composition forming the conversion coating according to the invention is preferably so less, preferably increased in the order of 1.0: 5.0, 1.0: 4.0, 1.0: 3.5, 1.0: 3.0, 1.0: 2.5, 1.0: 2.3, 1.0: 2.1, 1.0: 1.9, 1.0: 1.7 or 1.0: 1.6. independently preferably it is no more than, preferably increased in the order provided of 1.0: 0.2, 1.0: 0.4, 1.0: 0.6, 1.0: 0.8, 1.0: 1.0, 1.0: 1.1, 1.0: 1.2, 1.0: 1.3, 1.0: 1.4, or 1.0: 1.5. Independently, when both manganese and zinc are present in an aqueous liquid composition forming the conversion coating according to the invention, the manganese to nickel ratio is preferably at least, preferably increased in the proportioned order of 1.0: 2.0, 1.0: 1.7, 1.0: 1.5, 1.0: 1.3, 1.0: 1.2, 10: 1.1 or 1.0: 1.0, and preferably independently is not greater than, preferably increased in the proportioned order of 1.0: 0.2, 1.0: 0.5 , 1.0: 0.7, 1.0: 0.8 or 1.0: 0.9. An aqueous liquid composition forming the working conversion coating according to the invention preferably includes, at least in part and more preferably as the total of the optional component (F), a dissolved source of hydroxylamine. The source may be hydroxylamine itself but most users prefer to avoid the potential risks of handling pure hydroxylamine, so that a salt or complex of hydroxylamine is generally preferred. Hydroxylamine sulfate, which has the chemical formula (NU3? H) 2S? 4, is particularly preferred for reasons of economy and lacks ions which may be detrimental to the quality of the conversion coating formed, e.g., chloride ions, which may induce white spots of any of the zinc-rich areas of the coated substrate. Regardless of its actual source, the concentration in an aqueous liquid working conversion coating forming composition according to the invention, which is measured as its stoichiometric equivalent as the pure hydroxylamine, is preferably at least, preferably increased in the order provided of 0.2, 0.5, 0.8, 1.0, 1.1, 1.2, 1.3, 1.4 or 1.5 ppt and preferably independently is not greater than, preferably increased in the order provided by 5.4, 3.5, 3.0, 2.5, 2.3, 2.1, 1.9 or 1.8 ppt. If the surface of the substrate to be coated by conversion according to this invention includes a portion containing at least 45 percent aluminum, and / or a portion containing at least 85 percent zinc, an aqueous liquid composition The work conversion slurry former in accordance with the invention preferably includes a component (G) of simple fluoride anions and / or optional complexes; more preferably, if the surface of the substrate includes a portion containing at least 85 percent zinc, at least part of the fluoride present is in the form of fluoro, fluosilicic, fluotitanic and / or fluozirconic acids and their salts, greater preference fluosilicic acid and / or fluosilicate ions. Due to the competitive equilibrium deformation and dissociation of complex where the fluoride can participate in an aqueous liquid composition forming the working conversion coating according to this invention containing complex fluoromethalate and / or deliberately added fluohydric acid, the preferred concentrations for fluoride in this composition they are specified in terms of "active free fluoride", as measured by means of a fluoride sensitive electrode and associated instruments and methods which are described in US Pat. Nos. 3,350,284 and 3,619,300. The apparatus of instructions suitable for use can be obtained commercially under the name of Meter LINEGUARD® 101A from Parker Amchem Division ("PAM") of Henkel Corp., of Madison Heights, MI. "Active free fluoride" as this term is used herein was measured in relation to a Normal Activity 120E Solution Also commercially available from PAM. In short, the fluoride-sensitive electrode of the reference electrode provided with the LINEGUARD® 101 Meter are both immersed in the above-mentioned Normal Solution and the millivolts meter reading is set to 0 with a Normal Knob on the instrument, after being expected , if necessary to reduce any deviation in the readings. The electrodes are then rinsed with deionized or distilled water, dried, and immersed in a sample to be measured, which must be brought to the same temperature as the normal solution mentioned when it was used to zero the meter reading. The reading of the electrodes immersed in the sample is taken directly from the millivolt meter (hereinafter often abbreviated as "mv" or "mV") and converted into parts per million by comparison with millivolt readings obtained with solutions of a content known as free fluoride, usually solutions of sodium or potassium fluoride in water. The free fluoride content of an aqueous liquid composition forming the working conversion coating according to the invention, when a surface is being treated including areas that at least consist of 45 percent aluminum, preferably at least, preferably increased in the proportioned order of 100, 150, 200, 250, 300, 350, 375 or 400 parts per million and preferably independently is not greater than, preferably increased in the proportioned order of 1200, 1000, 900, 800, 750, 725, 700, 675, 650, 625 or 600 parts per million. If an area including areas that are at least 85 percent zinc but no areas that are at least 45 percent aluminum is to be treated, the free fluoride content is preferably no greater than, preferably increased in proportioned order of 100, 75, 60, 45, 40, 35, 30, 25, 20, 15 or 10 parts per million, but the total content of fluoborate, fluosilicate, fluotitanate and fluozirconate, which includes the stoichiometric equivalent as these ions of all the corresponding acids and the partially acidic salts added to the compositions, regardless of the actual degree of ionization that exists in the composition, is preferably at least, preferably increased in the proportionate order of 0.1, 0.3, 0.5, 0.7, 0.8, 0.9, 1.00, 1.10, 1.15 or 1.20 ppt and preferably independently is, mainly due to reasons of economy and with increased preference in the order provided not greater than 3.0, 2.5, 2.0, 1.8, 1.6, 1. 50, 1.45, 1.40, 1.35 or 1.30 ppt. More preferably, the total amount of these complex fluoride anions is the fluosilicate or its corresponding acid or acid salt. When the surfaces being treated are ferrous and do not include any areas that are predominantly either aluminum or zinc the fluoride can be omitted completely and this omission is usually preferred due to economic reasons. If any fluoride is present in the working compositions according to the invention to treat only ferrous substrates, the same preferences mentioned above apply for the maximum amount of the activity of the free fluoride in a free composition to treat free zinciferous surfaces. of aluminum.

In an aqueous liquid composition forming the working conversion coating according to the invention, the Total Acid and Free Acid Contents of the composition are preferably measured and controlled. These acid contents, compatible with the general practice in the field of phosphating, are expressed herein in "points", by which is meant the milliliters ("mi") of the NaOH concentration of 0.1 N required for evaluate a sample of an aliquot of 10 milliliters to a pH of 8.2 (eg, with an indicator of phenolphthalein) for the Total Acid and up to a pH of 3.8 (v.gr, with a blue indicator of bromophenol) for the Free Acid. In an aqueous liquid composition forming the working conversion coating according to the invention, the content of Free Acid is preferably at least preferably increased in the order of 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7. , 0.8, 0.9, or 1.0 point and preferably independently is not greater than, preferably increased in the proportionate order of 3.0, 2.5, 2.0, 1.8, 1.7, 1.6, or 1.5 points; independently, the content of the Preferred Total Acid is at least, preferably increased in the proportioned order of 15, 16, 17, 18, 19, 20 or 21 points and preferably independently is not greater than, preferably increased in the order provided of 50, 40, 35, 32, 30, 29 or 28 points. The contents of Free Acid and Total Acid can be adjusted within the preferred scale, without upsetting the preferred values for other constituents of an aqueous liquid composition forming conversion coating according to the invention, by additions, to an aqueous liquid composition conversion coating former otherwise satisfactory for small amounts of strongly alkaline materials such as sodium and potassium hydroxides, or acid ethers such as nitric and sulfuric acids, as appropriate to the direction in which it is desired change the contents of Free Acid and Total Acid, in a manner generally known to those skilled in the art. Preferably, the concentrated replenishment compositions according to the invention are liquid concentrates of a single package that is, they are aqueous liquids consisting of water in each of the components (A) to (G), as mentioned in that Preceding for the working compositions, which are desired to be prepared in the working compositions from the concentrated replenishment compositions together with any of the other desired ingredients in the working compositions, except possibly the strong acids or alkalis which do not form part of any of the components (A) to (G), and are added to the working compositions after the preparation thereof to slightly less than the final desired volume, in order to adjust the contents of Free Acid and Total Acid in the same, as defined above. Preferably, all the components except the water of a concentrated replacement composition according to the invention are present therein a concentration in such a way that the ratio of the concentration of each component in the composition of the replacement concentrate with respect to the concentration of the same component in the work composition that is desired to be prepared from the concentrated composition will be at least, preferably increased in the order given, of 5: 1.0, 10: 1.0, 20: 1.0, 30: 1.0, 40: 1.0 , or 50: 1.0. Preferably the concentrates are stable during storage within the temperature range from at least -20 ° to 50 °, or more preferably up to 80 ° C. The stability can be conveniently evaluated by measuring the contents of free acid and total acid as described above. If these values have not changed after being stored at more than 10 percent of their value before storage, the concentrate is considered stable to storage. Preferably increased in the order given, the concentrates according to the invention will be stable during storage and are therefore defined after being stored for 1, 3, 10, 30, 60 or 200 days. The actual conversion coating forming step in a process according to this invention is preferably carried out at a temperature that is at least, preferably increased in the order of 35 ° C, 38 ° C, 41 ° C. , 44 ° C, 46 ° C or 48 ° C, and preferably independently is, mainly for reasons of economy, not greater than 70 ° C, 65 ° C, 60 ° C, 55 ° C, 53 ° C, 51 ° C or 50 ° C. Mainly due to economy reasons, the contact time between the surface of the metal being coated and a working composition according to the invention preferably not greater than, preferably increased in the proportioned order of 200, 150, 120, 100, 80, 70, 60, 50, 40, 30, 25, 20, 17, 14, 11, 9.0, 7.0, 5.0, 4.0, 3.0 or 2.0 seconds, if a uniform coating is formed within that period of time adequately protective. For the rest, a process according to the invention is preferably made to work under the conditions conventional in the art for compositions that are otherwise similar to the compositions according to the invention, except that to replace an amount conventional nitrite accelerator for all hydroxylamine, acrylate and / or methacrylate polymer, and at least the difunctional acids and / or hydro acids described above for the compositions according to this invention. Further, in a process according to the invention which includes other steps than the zinc phosphate conversion coating with a composition as described above, the other preferred steps are conventional per se. The practice of this invention can also be appreciated taking into account the following non-limiting examples and comparison examples of work.

GENERAL PROCEDURE CONDITIONS The substrates used and their abbreviations are used in the subsequent tables as shown in Table 1, which is presented below. The substrates were in the form of conventional rectangular test panels. The processing sequence used is shown in Table 2 and its notes. All materials identified by one of the brands DEOXYLYTE®, FIXODINE®, or PARCO® can be obtained commercially from Parker Amchem Division of Henkel Corp., Madison Heights, Michigan and / or Henkel Metallchimie, Dusseldorf, Germany, along with instructions to use them as will be mentioned below.

Table 1 Type of Substrate Metal Abbreviation CRS cold-rolled steel Electro-galvanized steel on one side 1EG Hot-dip galvanized steel HDG Electro-galvanized steel on both sides 2EG Z-iron zinc alloy Z-I Table 2 Action of the Fluid Process Used TemperaTiempo, tura, ° C. Seconds Primary Cleaning by 21 grams / Liter 49 90 Spraying of the PARCO® 1502 Cleaner in water Spray Rinse Water from Wrench 49 30 Activation Conditioner 20-25 30 FIXODINE® Z-8 11 ppm Ti Phosphatation See 49 10,120 * subsequent tables Spray Water Rinse Key 20-25 30 Post-rinse 0. 25% of Pos20-25 30 enj uague DEOXYLYTE® 54 NC in water Spray Rinse Deionized water 20-25 15 (Table 2 (continued) Fitting Notes for Table 2 * The entire panel was immersed in the phosphating composition for 10 seconds. Then the upper half of the panel was removed. The lower half remained submerged for a total of 120 seconds, and the entire panel was then removed from contact with the phosphating composition. Abbreviations for Table 2 Temp. = Temperature; Sec. = Seconds.

Work Phosphating Compositions The most important components of the different work compositions are shown in Table 3; the rest not shown in the Table is water or counter-ions, the latter being predominantly sodium to serve as counterions for a considerable fraction of the phosphate content. An aqueous sodium hydroxide solution was used when it was necessary to decrease the free acid content. Nitric acid was added in small amounts as the citrate concentration was increased to avoid undesired decreases in the free acid content without changing the ratio of zinc to phosphate. Any free fluoride content indicated in the Table by a specific number was measured by a fluoride-sensitive electrode in the manner described above and added as hydrofluoric acid. The contents of free fluoride preceded by the sign (<) "less than" were measured in the same manner, but also means that there is no hydrofluoric acid or other source of fluoride not formed in known complex that was deliberately added; the activity of free fluoride was presumably caused by small concentrations of hydrofluoric acid known to exist in the fluosilicic acid that was deliberately added. The source of the acrylate polymer shown in Table 3 was an Acusol ™ 410 polymer solution in water, a product commercially available from Rohm & Haas Co. and which is disclosed by its supplier which contains 54 weight percent of an acrylic acid homopolymer wherein 20 percent of the carboxylic residues are neutralized with sodium hydroxide, having the polymer in the total form of acid a weight average molecular weight of 1000 and a number average molecular weight of 650.

Table 3 Unit of the Quantity of the Ingredient in the Composition Ingredient and Example Number: concentration 1 2 3 4 5 6 7 8 9 10 ions of Zn + 2, ppt 1.1 1.1 1.1 1.1 1.05 1.1 1.1 1.01 1 1 ions of P? 4 ~ 3, ppt 14 14 14 14 13.7 14 14 13.7 14 14 ions of Mn + 2, ppt 0.8 0.8 0.8 0.8 0.81 0.8 0.8 0.84 0.8 0.8 Ni + 2 ions, ppt 0.8 0.8 0.8 0.8 0.78 0.8 0.8 0.8 0.8 0.8 Slt dihydrate. Slt. Slt. Slt. Slt. Slt. Slt. Slt. Slt. Slt. sodium citrate, ppt (NH30H) 2S04, ppt 1.7 1.7 1.7 1.7 1.7 1.7 1.7 1.7 1.7 1.7 Free Acid, points 1.5 1.7 1.0 1.0 1.0 1.0 1.5 1.0 0.7 0.6 Total Acid, points 27 28 27 21 25 27 27 26 27 27 Acrylate polymer, ppm 10 10 10 25 25 25 25 50 50 50 H2SiF6, ppt 1.25 1.25 1.25 1.25 1.25 1.25 1.25 1.25 1.25 1.25 Activity of F ~ 690 690 690 < 25 < 25 680 680 670 67 ° 670 Free, ppm Abbreviation for Table 3 Slt. = see the following chart (s) The citrate concentrations in the working phosphating compositions and the resulting coating weights and glass sizes are shown in Tables 4 to 11.

Table 4: RESULTS WITH 10 PARTS PER MILLION OF THE ACRYLATE POLYMER IN CRS SUBSTRATES Composi- Conc. of Coating Weights Other Size # Citrate gram / m2 Crystal Observation - micrometer upper Lower 0. 10 1.10 2.62 8-10 SRD 0. 20 1.17 2.83 5-8 SRD 0. 30 0.70 2.90 5-8 SRD 3 0.30 1.57 2.67 5-8 SRD 3 0.40 0.96 2.68 5-8 SRD 3 0.50 0.99 2.86 3-5 SRD 3 0.65 1.30 2.87 3-5 SRD 3 0.80 1.38 2.71 3-5 DVSR 3 1.00 1.04 2.52 3 D (Table 4 Continuation) Additional abbreviations for Table 4 (See notes for previous tables and main text for others) Comp. # = Number of the Composition (from Table 3); Conc. = Concentration; g / m ^ = grams per square meter; μ = micrometers; SRD = Surface rust and dusting observed after phosphating; DVSR Very slight superficial rusting and dusting observed after phosphating; D = Dusting but no observable rust after phosphating.

Table 5: RESULTS WITH 10 PARTS PER MILLION OF THE POLYMER OF ACRILATO IN THE 1EG SUBSTRATES Comp. Conc. Coating Weight, Glass Size, Other # of g / m2 μ observe- Citratociones OSS OGS OSS OGS Sup Inf Sup Inf 0. 10 1.12 3.01 2.88 2.82 5-10 ~ 10 1 0.20 0.88 2.80 2.83 2.97 5-10 2 0.30 0.70 3.07 2.97 2.76 5-10 5-10 D 3 0.30 1.59 2.43 2.14 2.78 5-10 5-10 D 3 0.40 1.14 2.66 2.80 2.83 5-10 N.m. D 3 0.50 1.22 2.40 3.06 2.68 8 5-10 D 3 0.65 1.27 2.37 2.65 2.72 6 5 D 3 0.80 1.14 2.10 2.72 2.71 5 5 D 3 1.00 1.00 2.07 2.11 2.44 5 5 D Additional abbreviations for Table 5 (See the notes for the previous tables and the main text for the others) OSS = on the steel side; OGS = on the galvanized side; N.m. = Not measured Table 6: RESULTS WITH 10 PARTS PER MILLION OF THE ACRYLATE POLYMER IN OTHER SUBSTRATES On a substrate On a substrate On a substrate of HDG 2EG of Z-I Weight of Reverse- Size Weight of Reverse- Size Weight of Reverse- Size of the g /? R¿ of timiento g / raf- of g y- Sup Inf Crystal, Sup Inf Crystal Sup Inf Crystal μ μ μ 2 . 96 2. 84 10 3. 08 2 .52 5 2. 13 4. 10 15-20 Additional abbreviation for Table 6 (See notes for the previous tables and the main text for the others) Coating Weight = Coating Weight General Note for Table 6 The phosphating composition used for all the results in this table was Number 3 of Table 3 with 1.00 ppt of citrate. No superficial rust or dusting of the coating was observed. TABLE 7: RESULTS WITH 25 PARTS PER MILLION ACRYLATE POLYMER IN CRS SUBSTRATES Comp. Weight of the Coating Weights, Other Size # Citrate g / m2 Glass Observation - Lower Upper 4 0.00 * 0.61 * 2.08 * 15 - 20 * SRD * 4 0.10 0.93 3.76 15 - 20 SRD 4 0.20 1.22 3.62 10 - 15 SRD 4 0.30 1.04 3.15 8 - 10 SRD 0.30 1.30 2.85 5 - 10 SRD 0.40 1.35 2.82 5 - 10 SRD 0.50 1.24 2.99 5 - 10 DVSR 6 0.50 1.09 3.35 3 - 6 D 7 0.50 0.34 2.1 + 0.7 3 - 6 DVSR Note to the Fit for Table 7 * Example of comparison, not according to the invention.

Table 8: RESULTS WITH 25 PARTS PER MILLION OF THE ACRYLATE POLYMER IN THE 1EG SUBSTRATES Comp. Conc. Weight Coating, Size of Other # of g / m2 Crystal μ Observa- Citrate OGS tions OSS OGS Sup Inf Sup Inf 4 0.00 * 0.66 * 2.24 * 2.51 * 3.28 * 10 - 15 * SRD * 4 0.10 1.09 4.47 2.73 3.14 8 - 10 D 4 0.20 1.04 4.73 3.29 3.10 8 - 10 D 4 0.30 0.91 4.06 3.29 3.15 5 - 8 D 0.30 1.36 3.18 2.76 2.90 5- 8 D 0.40 1.34 3.19 2.85 2.96 5 - 8 D 0.50 1.52 3.18 2.78 3.04 5 - 8 D 6 0.50 0.83 5.08 2.38 3.95 5 D 7 0.50 0.69 2.98 3.71 3.77 5 D Note to the fit for Table 8 * The comparison example is not in accordance with the invention.

Table 9: RESULTS WITH 25 PARTS PER MILLION ACRYLATE POLYMER IN OTHER SUBSTRATES Composite of Substrate In Substrate In Substrate # Citrate of HDG of 2EG of Z-I Weight of Re- Weight of Re- Weight of Coating clothing dressing g / m ^ g / m ^ g / m ^ Sup Inf Sup Inf Sup Inf 0. 30 1.68 3.04 3.13 2.93 0.41 3.49 0. 50 3.38 2.81 3.25 3.27 0.64 4.66 General Note for Table 9 A superficial but rust-free dusting after phosphating was observed for both examples in this table.

Table 10: RESULTS WITH 50 PARTS PER MILLION ACRYLATE POLYMER IN CRS SUBSTRATE Composition - Weight Coating Conc. Size Others tion # Citrate g / m2 of Observations Crystal Upper Lower 8 0.10 1.06 1.87 8-10 DVSR 9 0.10 0.58 2.81 8-10 SRD 0.15 1.05 4.80 8-10 SRD 9 0.20 0.93 3.64 8-10 SRD Table 11: RESULTS WITH 50 PARTS PER MILLION OF THE ACRYLATE POLYMER IN THE 1EG SUBSTRATES Comp. Conc. Weight Coating Size of Other # of g / m2 Crystal, μ Obser- Citrate Vacations OSS OGS OSS OGS Sup Inf Sup Inf 8 0.10 0.48 2.62 3.11 4.21 10 15 D 9 0.10 1.04 4.71 4.02 4.20 8-10 15 D 0.15 0.91 3.02 3.84 4.27 8-10 10 D 9 0.20 0.69 3.75 3.79 3.84 8 5 D

Claims (20)

CLAIMS:

1. A composition of aqueous liquid material suitable either as such or after dilution with water to form a phosphate conversion coating on a metal substrate by contact therewith, the composition comprises water and: (A) a concentration of cations of zinc dissolved; (B) a concentration of dissolved phosphate anions; (C) a concentration of a dissolved component that is selected from the group consisting of organic acids and anions thereof which (i) contain at least two residues per molecule which are selected from the group consisting of carboxyl and carboxylate residues and hydroxyl residues that are not part of a carboxyl group and (ii) contain no more than 12 carbon atoms per molecule; and (D) a concentration of a dissolved component that is selected from the group consisting of polymer molecules containing more than 12 carbon atoms per molecule and wherein at least 50 percent of the polymer molecules are constituted of one or more waste with one of the general chemical formulas:

CH3 I - (CH2-CH) - or - (CH2-C) -, I I C = 0 C = 0 I I

OM OM wherein M represents a hydrogen atom, a monovalent cation or a monovalent fraction of a polyvalent cation. 2. An aqueous liquid matter composition according to claim 1, wherein: the concentration of component (A) has a ratio with respect to the concentration of component (B) that is from about 1.0: 40 to about 1.0: 5.0; component (C) is selected from the group consisting of anions and molecules each of which contains both at least one carboxyl or carboxylate residue and at least one hydroxyl residue that is not part of any carboxyl or carboxylate residue; at least about 30 percent by number of the "M" residues shown in the general chemical formulas in claim 1 of component (D) are hydrogen, component (D) has a weight average molecular weight of about 500 to about 9000; and the composition further comprises at least one cation of divalent manganese and divalent nickel in a total amount such that the concentration of the zinc cations has a relationship with respect to the total amount of the divalent manganese cations and divalent nickel. which is from 1.0: 3.5 to approximately 1.0: 0.6. 3. An aqueous liquid matter composition according to claim 2, wherein the ratio of the concentration of the component (A) to the concentration of the component (B) is from about 1.0: 18 to about 1.0: 10; at least about 60 percent by number of "M" residues are hydrogen; at least about 60 percent of component (D) consists of acrylate residues; component (D) has a weight average molecular weight of from about 700 to about 1300; the composition comprises both divalent manganese and divalent nickel cations dissolved in concentrations such that the concentration of the manganese has a relationship with respect to the concentration of the nickel, which is from about 1.0: 1.5 to about 1.0: 0.7; and the ratio of the concentration of the zinc cations to the total amount of divalent manganese cations and divalent nickel cations is from about 1.0: 3.5 to about 1.0: 0.6.

4. An aqueous liquid composition according to claim 2, wherein: the concentration of component (A)) is from about 0.30 to about 2.0 ppt; the concentration of component (B) is from about 6 to about 50 ppt; the concentration of component (C) is from about 0.2 to about 25 mM per kilogram; the concentration of component (D) is from about 5 to about 200 parts per million; and the concentration of the dissolved divalent manganese cations is from about 300 to about 3000 parts per million.

5. An aqueous liquid composition according to claim 4, wherein: the concentration of component (A) is from about 0.50 to about 1.8 ppt; the concentration of component (B) is from about 8 to about 30 ppt; the concentration of component (C) is from about 0.3 to about 15 mM per kilogram; the concentration of the component (D) of about 10 to about 100 parts per million; the concentration of dissolved divalent manganese cations is from about 500 to about 2000 parts per million.

6. An aqueous liquid composition according to claim 5, wherein: the concentration of component (A) is from about 0.60 to about 1.6 ppt; the concentration of component (B) is from about 10 to about 21 ppt; the ratio of the concentration of component (A) to the concentration of component (B) is from about 1.0: 30 to about 1.0: 8.0; the concentration of component (C) is from about 0.4 to about 10 mM per kilogram; at least about 70 percent of the component (D) consists of acrylate and methacrylate residues of which is at least 50 percent in number have hydrogen as the "M" residues; the weight average molecular weight of component (D) is from about 700 to about 7000; the concentration of component (D) is from about 15 to about 85 parts per million; the concentration of the dissolved divalent manganese cations is about 600 to 1500 parts per million; and the stoichiometric equivalent concentration of the hydroxylamine is from about 1.0 to about 5 ppt.

7. An aqueous liquid composition according to claim 6, wherein: the concentration of component (A) is from about 0.70 to about 1.4 ppt; the concentration of component (B) is from about 11.5 to about 19 ppt; the ratio of the concentration of the component (A) to the concentration of the component (B) is from about 1.0: 27 to about 1.0: 10.0; component (C) is selected from the group consisting of citric acid, gluconic acid, and heptogluconic acid and the water soluble salts of all these acids; the concentration of component (C) is from about 1.0 to about 7 mM per kilogram; at least about 75 percent of the component (D) consists of acrylate and methacrylate residues of which at least about 60 percent by number have hydrogen as the "M" residues; the weight average molecular weight of component (D) is from about 750 to about 4500; the concentration of component (D) is from about 15 to about 45 parts per million; the concentration of the dissolved divalent manganese cations is from about 700 to about 1300 parts per million; and the composition further comprises a dissolved source of hydroxylamine in an amount to provide a stoichiometric equivalent concentration of hydroxylamine which is from about 1.2 to about 2.3 ppt.

8. An aqueous liquid composition according to claim 7, wherein: the concentration of component (A) is from about 0.80 to about 1.3 ppt; the concentration of the component is from about 12.2 to about 17 ppt; the ratio of the concentration of the component (A) to the concentration of the component (B) is from about 1.0: 21, to about 1.0: 10.0; the concentration of component (C) is from about 1.2 to about 5 mM per kilogram; the weight average molecular weight of component (D) is from about 750 to about 3000; the concentration of component (D) is from about 15 to about 35 parts per million; the concentration of the dissolved divalent manganese cations is from 750 to about 1200 parts per million; and the stoichiometric equivalent concentration of the hydroxylamine is from about 1.3 to about 2.1 ppt.

9. An aqueous liquid composition according to claim 8, wherein: the concentration of the component (A) is from about 0.85 to about 1.20 ppt; at least about 70 percent of the component (D) consists of acrylate residues of which at least 70 percent of the number have hydrogen as the "M" residues; the weight average molecular weight of component (D) is from about 900 to 1700; the concentration of dissolved divalent manganese cations is about 800 to 1000 parts per million; and the composition also comprises nickel cations dissolved in a concentration of about 200 to about 1200 parts per million.

10. An aqueous liquid composition according to claim 9, wherein: the concentration of component (A) is from about 0.95 to about 1.15 ppt; the concentration of component (B) is from about 13.0 to about 16.0 ppt; the ratio of the concentration of the component (A) to the concentration of the component (B) is from about 1.0: 18 to about 1.0: 13.0; component (C) is selected from the group consisting of citric acid, gluconic acid and heptoglyconic acid and the water soluble salts of all these acids; the concentration of component (C) is from about 1.6 to about 4.1 mM per kilogram; at least about 80 percent of the component (D) consists of acrylate residues, of which at least 80 percent by number have hydrogen as the "M" residues; the weight average molecular weight of component (D) is from about 900 to about 1200; the concentration of component (D) is from about 20 to about 30 parts per million; the concentration of the dissolved divalent manganese cations is from about 800 to about 1000 parts per million; the concentration of the dissolved nickel cations is from about 600 to about 900 parts per million; and the concentration of the stoichiometric equivalent of the hydroxylamine is from about 1.5 to about 1.8 ppt.

11. A process for forming a phosphate conversion coating on a surface selected from the group consisting of at least one zinciferous surface of iron, steel, zinc-iron alloy, galvanized steel and other predominantly zinciferous surfaces, and aluminum and its alloys containing at least 45 weight percent aluminum, the process comprises contacting the surface with a composition according to claim 10, at a temperature of about 35 ° C to about 70 ° C. for a period of time not greater than 100 seconds, the composition according to claim 10, has a Free Acid content of about 1.0 to about 1.5 points, a Total Acid content of about 20 to about 28 points; wherein, (i) if the surface includes a portion containing at least 45 percent aluminum, that composition according to claim 10, further comprises constituents that contain fluorine in an amount such as to result in a value of about 400 to about 600 parts per million free fluoride as measured by means of a fluoride sensitive electrode; and (ii) if the surface includes a portion containing at least 85 percent zinc but does not include any portion containing at least 45 percent aluminum, this composition according to claim 10 further comprises a content of Fluosilicate which is from about 1.10 to about 1.40 ppt, and this composition according to claim 10, has a free fluoride value which is no more than about 20 parts per million as measured by means of a fluoride sensitive electrode.

12. A process for forming a phosphate conversion coating on a surface that is selected from the group consisting of at least one of the surfaces of iron, steel, zinc-iron alloy, galvanized steel and other predominantly zinciferous surfaces, and aluminum and its alloys containing at least 45 weight percent aluminum, this process comprises contacting the surface with a composition according to claim 9 at a temperature of about 35 ° C to about 70 ° C for a period of time. of time not greater than 100 seconds, the composition according to claim 9, has a Free Acid content of about 0.6 to about 1.5 points, and a Total Acid content of about 15 to about 40 points; wherein, (i) if the surface includes a portion containing at least 45 percent aluminum, this composition according to claim 9 further comprises constituents that contain fluorine in an amount such as to result in a value of about 250. to about 1200 parts per million free fluoride as measured by means of a fluoride sensitive electrode; and (ii) if the surface includes a portion that contains at least 85 percent zinc but does not include any portion containing at least 45 percent aluminum, this composition according to claim 9, further comprises a total content of fluoborate, fluosilicate, fluotitanate and fluozirconate which is from about 0.5 to about 2.5 ppt, and this composition according to claim 9 has a free fluoride value which is not more than about 100 parts per million as measured by means of a fluoride sensitive electrode.

13. A process for forming a phosphate conversion coating on a surface that is selected from the group consisting of at least one of the iron surfaces, steel, zinc-iron alloy, galvanized steel and other predominantly zinciferous surfaces, and aluminum and its alloys containing at least 45 weight percent aluminum, the process comprises contacting the surface with a composition in accordance with the claim 8, at a temperature of about 35 ° C to about 70 ° C for a period of time not greater than 100 seconds; the composition according to claim 8 has a Free Acid content of about 0.6 to about 1.5 points, and a Total Acid content of about 15 to about 40 points; wherein, (i) if the surface includes a portion containing at least 45 percent aluminum, this composition according to claim 8 further comprises constituents containing fluorine in an amount so as to result in a value of approximately 250 to about 1200 parts per million of the free fluoride as measured by means of a fluoride sensitive electrode; and (ii) if the surface includes a portion containing at least 85 percent zinc but does not include any portion containing at least 45 percent aluminum, the composition according to claim 8 further comprises a total content of fluoborate, fluosilicate, fluotitanate and fluozirconate that is from about 0.5 to about 2.5 ppt, and the composition according to claim 8 has a free fluoride value that is not more than about 100 parts per million, as measured by medium of a fluoride sensitive electrode.

14. A process for forming a phosphate conversion coating on a surface that is selected from the group consisting of at least one of the surfaces of iron, steel, zinc-iron alloy, galvanized steel and other surfaces predominantly zinciferous and aluminum and its alloys containing at least 45 weight percent aluminum, the process comprises contacting the surface with a composition according to claim 7, at a temperature of about 35 ° C to about 70 ° C for a period of time. of time not greater than 100 seconds, the composition according to claim 7 has a Free Acid content of about 0.2 to about 1.5 points, and a Total Acid content of about 15 to about 40 points; wherein (i) if the surface includes a portion containing at least 45 percent aluminum, this composition according to claim 7 further comprises constituents that contain fluorine in an amount such as to result in a value of about 250 at about 1200 parts per million free fluororubic, is measured by means of a fluoride sensitive electrode; and (ii) if the surface includes a portion containing at least 85 percent zinc but does not include any portion containing at least 45 percent aluminum, the composition according to claim 7 further comprises a total content of fluoborate, fluosilicate, fluotitanate, and fluozirconate that is from about 0.5 to about 2.5 ppt, and the composition according to claim 7 has a free fluoride value that is not greater than about 100 parts per million as measured by a fluoride sensitive electrode.

15. A process for forming a phosphate conversion coating on a surface that is selected from the group consisting of at least one of the surfaces of iron, steel, zinc-iron alloy, galvanized steel and other predominantly zinciferous surfaces, and aluminum and its alloys containing at least 45 weight percent aluminum, and the process comprises contacting the surface with a composition according to claim 6 at a temperature of about 35 ° C to about 70 ° C during a a period of time not greater than 100 seconds, the composition according to claim 6, has a free acid content of about 0.2 to about 1.5 points, and a Total Acid content of about 15 to about 40 points, wherein (i) ) if the surface includes a portion containing at least 45 percent aluminum, this composition according to claim 6 , further comprising constituents containing fluorine in an amount such as to result in a value of from about 250 to about 1200 parts per million free fluoride as measured by means of a fluoride-sensitive electrode.; and (ii) if the surface includes a portion containing at least 85 percent zinc but does not include any portion containing at least 45 percent aluminum, the composition according to claim 6 further comprises a total content of fluoborate, fluosilicate, fluotitanate and fluozirconate that is from about 0.5 to about 2.5 ppt, and the composition according to claim 6 has a free fluoride value that is not greater than about 100 parts per million as measured by an electrode sensitive to fluoride.

16. A process for forming a phosphate conversion coating on a surface that is selected from the group consisting of at least one of the surfaces of iron, steel, zinc-iron alloy, galvanized steel and predominantly zinciferous surfaces, and aluminum and its alloys containing at least 45 weight percent aluminum, the process comprises contacting the surface with a composition according to claim 5, at a temperature of about 35 ° C to about 70 ° C for a period of time not greater than 100 seconds, the composition according to claim 5, has a Free Acid content of about 0.2 to about 1.5 points, and a Total Acid content of about 15 to about 40 points; wherein, (i) if the surface includes a portion that contains at least 45 percent aluminum, the composition according to claim 5 further comprises constituents that contain fluorine in an amount such as to result in a value of about 250 to about 1200 parts per million of the free fluoride as measured by means of a chloride sensitive electrode; and (ii) if the surface includes a portion that contains at least 85 percent zinc but does not include any portion containing at least 45 percent aluminum, the composition according to claim 5 also comprises a total content of fluoborate, fluosilicate, fluotitanate, and fluozirconate that is from about 0.5 to about 2.5 ppt, and the composition according to claim 5 has a free fluoride value that is no greater than about 100 parts per million, as measured by of an electrode sensitive to fluoride.

17. A process for forming a phosphate conversion coating on a surface that is selected from the group consisting of at least one of the surfaces of iron, steel, zinc-iron alloy, galvanized steel and other zinciferous surfaces, predominantly, and aluminum and its alloys containing at least 45 weight percent aluminum, the process comprises contacting the surface with a composition according to claim 4, at a temperature of about 35 ° C to about 70 ° C. for a period of time not greater than 100 seconds, the composition according to claim 4, has a free acid content of about 0.2 to about 1.5 points, and a Total Acid content of about 15 to about 40 points; wherein, (i) if the surface includes a portion containing at least 45 percent aluminum, the composition according to claim 4 further comprises constituents that contain fluorine in an amount such as to result in a value of about 250 to about 1200 parts per million of the free fluoride as measured by means of a fluoride sensitive electrode; and (ii) if the surface includes a portion containing at least 85 percent zinc but does not include any portion containing at least 45 percent aluminum, the composition according to claim 4 also comprises a total content of fluoborate, fluosilicate, fluotitanate and fluozirconate that is from about 0.5 to about 2.5 ppt, and the composition according to claim 4 has a free fluoride value that is not greater than about 100 parts per million as measured by of an electrode sensitive to fluoride.

18. A process for forming a phosphate conversion coating on a surface selected from the group consisting of at least one of iron, steel, zinc-iron alloy, galvanized steel and other surfaces predominantly zinciferous and aluminum and their alloys containing at least 45 weight percent aluminum, the process comprises contacting the surface with a composition according to claim 3; wherein in the composition according to claim 3: the concentration of component (A) is from about 0.40 to about 2.0 ppt; the concentration of component (C) is from about 0.2 to about 25 mM per kilogram; the concentration of component (D) is from about 5 to about 200 parts per million; if the surface includes a portion containing at least 45 percent aluminum, this composition further comprises constituents which contain fluorine and an amount such as to result in a value of about 250 to about 1200 parts per million free fluoride, such as measured by means of a fluoride sensitive electrode; if the surface includes a portion containing at least 45 percent aluminum, this composition further comprises a total content of fluoborate, fluosilicate, fluotitanate and fluozirconate that is from about 0.5 percent to about 2.5 ppt, and the composition has a value of free fluoride that is no greater than about 100 parts per million as measured by means of a fluoride-sensitive electrode; and the composition has a Free Acid content of about 0.2 to about 1.5 points, and a Total Acid content of about 15 to about 40 points.

19. A process for forming a phosphate conversion coating on a surface that is selected from the group consisting of at least one of iron, steel, zinc-iron alloy, galvanized steel and other predominantly zinciferous surfaces, and aluminum and its alloys that contain at least 45 weight percent aluminum, the process comprises contacting the surface with a composition according to claim 2, wherein in the composition according to claim 2; the concentration of component (A) is from about 0.2 to about 2.0 ppt; the concentration of component (C) is from about 0.1 to about 50 mM per kilogram; the concentration of component (D) is at least about 5 parts per million; if that surface includes a portion containing at least 45 percent aluminum, that composition further comprises constituents containing fluorine in an amount such as to result in a value of about 250 to about 1200 parts per million free fluoride, such as measured by means of a fluoride sensitive electrode; and if the surface includes a portion containing at least 85 percent zinc but does not include any portion containing at least 45 percent aluminum, that composition further comprises a total content of fluoborate, fluosilicate, fluotitanate and fluozirconate which is from about 0.5 to about 2.5 ppt and the composition has a free fluoride value that is no greater than about 100 parts per million as measured by means of a fluoride sensitive electrode; and the composition has a Free Acid content of about 0.2 to about 1.5 points, and a Total Acid content of about 15 to about 40 points.

20. A process for forming a phosphate conversion coating on a metal surface, the process comprising contacting the surface with a composition according to claim 1, wherein in the composition according to claim 1: the concentration of component (A) is from about 0.2 to about 2.0 ppt; the concentration of component (B) is from about 5 to about 100 ppt; the concentration of component (C) is from about 0.2 to about 25 mM per kilogram; the concentration of component (D) is from about 5 to about 200 parts per million; and the composition has a Free Acid content of about 0.1 to about 3 points and a Total Acid content of about 15 to about 50 points;