CA2236173A1 - Finely crystalline and/or fast phosphate conversion coating composition and process - Google Patents
Finely crystalline and/or fast phosphate conversion coating composition and process Download PDFInfo
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Abstract
A combination of difunctional organic acid, preferably a hydroxy acid such as citric acid, or salt thereof with acrylic acid/acrylate polymers in zinc phosphate conversion coating forming liquid compositions, preferably also containing hydroxylamine, results in crystal size refinement in the coating formed and/or faster formation of a sufficiently thick conversion coating to protect against subsequent rusting of a ferrous substrate.
Description
W O 97/17480 PCT~US96/17086 Description FINELY CRYSTALLINE AND/OR FAST PHOSPHATE CONVERSION
COATING COMPOSITION AND PROCESS
BACKGROUND OF THE INVENTION
Field of the Invention This invention relates to compositions and processes for depositing zinc phos-phate cont~ining conversion co~ting~ on metal surfaces, particularly the surfaces of iron, steel, zinc-iron alloy, galvanized steel and other predominantly zinciferous surfaces, and al.l",;"~l", anditsalloysthatcontainatleast45 %byweightofalllminllm Theinventionparticularly relates to such compositions and processes that produce, at a high coating speed, a conversion coating with a very fine average crystal size.
Statement of Related Art The general process of zinc phosphate conversion coating is well known in the art. See, e.g., M. ~.qm~her, "Ecologically Safe Pretre~tment~ of Metal Surfaces", Hen-kel-Referate 30 (1994), pp. 138 - 143, which, except to the extent that it may be contrary to any explicit st~tem~nt herein, is hereby incol~uldl~d herein by reference. In brief, con-tact of active metals with aqueous acidic compositions cont~inin~ zinc and phosphate ions results in the deposition on the active metal sllrf~es of a conversion coating con-taining zinc phosphate. If the active metal is ferrous, iron phosphates are usually includ-ed in the coating, and in modern practice nickel andtor m~ng~nese are often included in the coating composition and thereby in the coating formed. In order to speed the process and improve the uniformity of the coating, it is c~Lolll~y to include in the coating com-position a component called an "accelerator" that does not usually become incorporated into the coating formed. Typical widely used accelerators include nitrate, nitrite, and chlorate ions, water soluble niLloal~ollldLic organic compounds such as p-nitrobenzene sul-fonic acid, and hydroxylamine (the latter almost always in the form of salts or complex-es).
~, 25 A frequently observed problem with prior art conversion coatings, particularly on cold rolled steel, has been the production of small rusty spots on areas of the treated ~ul~Lldl~ metal that were blocked from full contact with the conversion coating forming liquid composition by small gas bubbles that were formed andtor trapped on the substrate WO 97/17480 PC~r~US96/17086 surface during the conversion coating treatment process. It is believed that the water vapor inside such bubbles is sufficient to cause rusting before the desired formation of a protective conversion coating can progress sufficiently far to prevent rust, and once a rusty spot has formed, it can not usually be covered satisfactorily later even by full con-5 tact with the conversion coating forming liquid composition.
DF!~CRIPTION OF THE INVENTION
Object of the Invention One object of this invention is to provide a composition and process for phosphat-ing that will provide a protective conversion coating with a more refined crystal size than 10 is now generally achieved by zinc phosphating. Another ~It~rn~tive or concurrent object is to provide a zinc phosphating composition and process that will form a high quality protective conversion coating during a brief contact time with a metal substrate to be coated, so that coil coating and other continuous phosphating operations can be run at higher speeds. Still another concurrent or alternative object is to avoid the formation of 5 surface rust on small areas of the treated substrate that are blocked by gas bubbles from full contact with the conversion coating solution. Other objects will be apparent from the description below.
General Principles of Description Except in the claims and the operating examples, or where otherwise expressly 20 indicated, all numerical quantities in this description indicating amounts of material or conditions of reaction and/or use are to be understood as modified by the word "about"
in describing the broadest scope of the invention. Practice within the numerical limits stated is generally preferred, however. Also, throughout the description and claims, unless expressly stated to the contrary: percent, "parts of', and ratio values are by weight;
25 the description of a group or class of materials as suitable or pler~ d for a given purpose in connection with the invention implies that mixtures of any two or more of the members of the group or class are equally suitable or ~ler~ d; description of constituents in chemical terms refers to the con~tit~l.ont~ at the time of addition to any combination specified in the description, and does not necessarily preclude chemical 30 interactions among the constituents of a mixture once mixed; specification of materials in ionic form implies the presence of sufficient counterions to produce electrical neutrality for the composition as a whole; any counterions thus implicitly specified should preferably be selected from among other con~tit lent~ explicitly specified in ionic form, to the extent possible; otherwise such counterions may be freely selected, except for avoiding counterions that act adversely to the objects of the invention; the terms ~ "molecule" and "mole" and their gr~mm~tiç~l variations may be applied to ionic, elem~nt~l, or any other type of chemical entities defined by the number of atoms of each type present therein, as well as to substances with well-defined neutral molecules; the first definition of an acronym or other abbreviation applies to all subsequent uses herein of the saTne abbreviation; and the term "polymer" includes "oligomer", "homopolymer", "copolyrner", "terpolymer", and the like.
Sllmm~ry of the Invention It has been found that one or more of the objects stated above for the inventioncan be achieved by the use of a conversion coating forming aqueous liquid composition that comprises, preferably consists eesçnti~lly of, or more preferably consists of, water and:
15 (A) dissolved zinc cations;
(B) dissolved phosphate anions;
(C) a dissolved component selected from the group consisting of organic acids and anions thereof that (i) contain at least two moieties per molecule that are selected from the group consisting of carboxyl and carboxylate moieties and hydroxyl moieties that are not part of a carboxyl moiety and (ii) do not contain more than 12 carbon atoms per molecule; and (D) a dissolved component selected from the group con~i~ting of polymer molecules which contain more than 12 atoms per molecule and in which at least 50 % of the polymer molecule is made up of one or more moieties with one of the formulas:
-(CHz-CH)- or -(CHz-C)-, C=O C=O
1 l OM OM
where M l~.ese~ a hydrogen atom, a monovalent cation, or a monovalent frac-tion of a polyvalent cation; and, optionally, (E) a component of dissolved metal cations selected from the group consisting of W O 97/17480 PCT~US96/17086 metal cations, exclusive of zinc cations, with a charge of at least two;
(F) a component of dissolved accelerator molecules, exclusive of any molecules that are part of any of the prececling components; and (G) a component of dissolved simple and/or complex fluoride anions, exclusive of any anions that are part of any of the preceAin~ components.
Various embo-liment~ of the invention include working compositions for direct use in treating metals, make-up conr~ntr~t~s from which such working compositions can be ~l~paled by dilution with water, replenisher concentrates suitable for m~int~inin~ op timum performance of working compositions according to the invention, processes for treating metals with a composition according to the invention, and extended processes including additional steps that are conventional per se, such as cleaning, activation with titaniurn phosphate sols (Jernstedt salts), rinsing, and subsequent painting or some similar overcoating process that puts into place an organic binder cont~ining protective coating over the metal surface treated according to a ,l~lv~l embodiment of the invention. Art-icles of manufacture including surfaces treated according to a process of the invention are also within the scope of the invention.
Description of Preferred Embodiments For a variety of reasons, it is sometimes l~lc;rcll~,d that compositions according to the invention as defined above should be sub~ lly free from many ingredients used in compositions for similar purposes in the prior art. Specifically, when maximum stor-age stability of a concentrate is desired, it is preferred, with increasing ~l~r~,.ellce in the order given, independently for each preferably minimi7ed component listed 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: nitrite, chlorate, chloride, bromide, iodide, organic compounds cont~inin~ nitro groups, hexavalentchromium, m~n~nPse in a valence state of four or greater, ferricyanide; ferrocyanide, and pyrazole compounds. ln contrast, in working solutions, accelerator components such as those included in this list have no known detrimental effect (except for the danger of white specking zinciferous surfaces treated with compositions that contain too much chloride, which is formed in situ from chlorate), but are generally not needed, and their absence may therefore be preferred for economic reasons.
The dissolved zinc cations required for nPcPc~ry component (A) may be obtained WO 97/17480 PCTrUS96/17086 from any soluble zinc salt or from zinc metal itself or any zinc co~ g compound that reacts with aqueous acid to form dissolved zinc cations. Normally ~lcrcll~,d sources, largely for economic reasons, are zinc oxide, zinc carbonate, and zinc dihydrogen phos-phate. In a working conversion coating forming aqueous liquid composition according 5 to the invention, the concentration of dissolved zinc cations preferably is at least, with increasing plcrclcnce in the order given, 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 parts per thousand (hereinafter usually abbreviated as "ppt") and independently preferably is not more than, with increasing plt;r~cllce in the order given, 2.0, 1.8, 1.6, 1.4, 1.30, 1.20, l.lS, or 1.10 ppt.
The dissolved phosphate ions that constitute necessary component (B) also may be obtained from a variety of sources as known in the general phosphate conversion coat-ing art. Because of a preference noted below for a substantial amount of total acid in a working conversion coating forming aqueous liquid composition according to the inven-tion, normally much of the phosphate ion content will preferably be supplied by phos-phoric acid added to the composition, and the stoichiometric equivalent as phosphate ions of all undissociated phosphoric acid and all its anionic ionization products in solution, along with the stoichiometric equivalent as phosphate ions of any dihydrogen phosphate, monohydrogen phosphate, or completely neutralized phosphate ions added to the compo-sition in salt form, are to be understood as forming part of component (B), irrespective of the actual degree of ionization that exists in the composition. In a working conversion coating forming aqueous liquid composition according to the invention, the concentration of component (B) preferably is at least, with increasing preference in the order given, 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 independently preferably is not more than, with increasing plefe,~llce in the order given, 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 compon-ent (A) to the concentration of component (B) in a conversion coating forming aqueous liquid composition according to the invention, whether working or concentrate, preferab-ly iS at least, with increasing preference in the order given, 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 independently pref-erably is not more than, with increasing l~lcfclence in the order given, 1.0:5.0, 1.0:6.0, W O 97/17480 PCT~US96/17086 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 carboxyl(ate) moiety and one hydroxyl moiety that is not part of any carboxyl(ate) moiety, more preferably from the group con~icting of citric acid, gluconic acid, and heptogluconic acid and the water soluble salts of all of these acids, most preferably from citric acid and its water soluble salts. Independently, the concentration of component (C) in a working conversion coating forming aqueous liquid composition according to the invention preferably is at least, with increasing preference 0 in the order given, 0.1, 0.2, 0.3, or 0.4 millimoles per kilogram of total composition (hereinafter usually abbreviated "mM/kg") and, if small crystal size of the conversion coating formed is desired, more preferably is at least, with increasing preference in the order given, 1.0, 1.2, or 1.6 mM/kg; if small crystal size of the conversion coating formed is desired and the concentration of component (D) is near the lower end of its preferred ranges as further described below, the con~entr~tion of component (C) in a working con-version coating forming aqueous liquid composition according to the invention still more preferably is at least 3.5 mM/kg. Independently, primarily for reasons of economy, the concentration of component (C) in a working composition according to the invention preferably is not more than, with increasing l~lcrelGllce in the order given, 50, 25, lS, 10, 7,5, 4.5, or 4.1 mM/kg, and if larger crystal size is acceptable, more preferably is not greater than, with increasing ~rt;rc~ ce in the order given, 3.2, 3.0, 2.8, 2.5, 2.2,1.9, or 1.7 mM/kg.
Component (D) preferably is selected from polymer molecules in which at least, with increasing p~crclcnce in the order given, 60, 70,75,80, 85, 90, or 95 % of the mole-2s cule consists of one or more moieties with one of the formulas:
fH3 -(CH2-fH)- or -(CH2-f)-, f=o f=o OM OM
more preferably the formula shown on the left, or in other words, acrylate rather than methacrylate moieties. Independently, with increasing ~ler~rcllce in the order given, at W O 97/17480 PCT~US96/17086 least 30, 50, 60, 70, or 80 nurnber percent of these acrylate and methacrylate moieties in component (D) have hydrogen rather than any other atom or cation in the position in the formula indicated by the symbol "M" in the formulas shown. Independently of bothother plcrc,cl,ces, the weight average molecular weight of the polymers in the component 5 (D), measured as its stoichiometric equivalent when all the acrylate and methacrylate moieties are in an acid form, preferably is at least, with increasing pLc;rcl~ ce in the order given, at least 400, 500, 600, 700, 750, 800, 850, 900, 950, or 975 and independently preferably is not more than, with increasing ~lcrclcnce in the order given, 10,000, 9000, 8000, 7000, 6000, 5000, 4500, 4000, 3500, 3000, 2500, 2000, 1700, 1400, 1300, 1250, 1200, 1 150, 1 100, or 1050. Also, independently of the other preferences for component (D), the concentration of component (D) in a working conversion coating forming aque-ous liquid composition according to the invention preferably is at least 5, 10, 15, 20, 22, or 24 ppm and independently preferably is not more than 300, 200, 100, 85, 75, 65, or 55 ppm and, unless the concentration of component (C) is not more than 0.4 mM/kg, 15 more preferably is not more than, with increasing preference in the order given, 45, 35, 30, or 26 ppm.
If high corrosion resistance after application of an organic protective coating to a metal substrate, subsequent to forming a conversion coating thereon by cont~cfinP: the substrate with a working conversion coating forming aqueous liquid composition accord-ing to the invention, is desired, as it usually is, a working conversion coating formingaqueous liquid composition according to the invention preferably contains one or more metal ions selected from optional component (E). Examples of preferred combinations of zinc ions with metal ions of component (E) in a working conversion coating forming aqueous liquid composition according to the invention are: Zn and Mn; Zn, Mn, and Co;
25 Zn, Mn, and Cu; Zn and Cu; Zn, Co, and Cu; and Zn, Mn, and Ni. It is especially pre-ferred for a working conversion coating forming aqueous liquid composition according to the invention to contain, as at least part of optional component (E), dissolved divalent m~n~nese cations in a concentration that preferably is at least, with increasing prefer-ence in the order given, 100, 200, 300, 400, 500, 550, 600, 650, 700, 750, 800, 825, or 30 835 ppm and independently preferably is, primarily for reasons of economy, not more than, with h~ ca,h~g ~,crt;,cllce in the order given, 4000, 3000, 2000, 1500, 1400, 1300, 1250, 1200, 1150, 1100, 1050, 1000, 950, or 900 ppm. Also, independently ofthe prefer-W O 97/17480 PCT~US96/17086 ences for m~n~n.oce as noted, it is especially preferred for a working conversion coating forming aqueous liquid composition according to the invention to include, as at least part of optional component (E), dissolved divalent nickel cations in a concentration that pref-erably is at least, with increasing preference in the order given, 100, 200, 300, 400, 500, 550, 600, 650, 700, 750, 765, 785, or 790 ppm and independently preferably is, primarily for reasons of economy, not more than, with increasing preference in the order given7 4000, 3000, 2000, 1500, 1400, 1300, 1250, 1200, 1150, 1100, 1050, 1000, 950, 900, or 850 ppm.
Independently of other pr~fe~ ces, the ratio of the concentration of zinc cations to the sum of the concentrations of m~nganese and nickel cations in a conversion coating forming aqueous liquid composition according to the invention preferably is at least, with increasingpl~ ce in the order given,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 and independently preferably is not more than, with increasingpreferenceintheordergiven, 1.0:0.2, 1.0:0.4, 1.0:0.6, 1.0:0.8, l.0:1.0, l.0:1.1, s 1.0:1.2, 1.0:1.3, 1.0:1.4, or 1.0:1.5. Independently, when both m~n~nese and nickel are present in a conversion coating forming aqueous liquid composition according to the in-vention, the ratio of m~ng7ln~se to nickel preferably is at least, with increasing plerelellce in the order given, 1.0:2.0, 1.0:1.7, 1.0: 1.5, 1.0:1.3, 1 .0 : 1.2, 1.0: 1.1, or 1.0: 1.0 and inde-pendently preferably is not more than, with increasing ~rerclcnce in the order given, 1.0:0.2, 1.0:0.5, 1.0:0.7, 1.0:0.8, or l.0:0.9.
A working conversion coating forming aqueous liquid composition according to the invention preferably includes, as at least part, and more preferably as all, of optional component (F) a dissolved source of hydroxylamine. The source may be hydroxylamine itself, but most users prefer to avoid potential hazards from hzln~lling pure hydroxylamne, So that a salt or complex of hydroxylamine is generally preferred. Hydroxylamine sul-fate, which has the chemical formula (NH30H)2SO4 is particularly preferred for economy and lack of any ions that may be deleterious to the quality of conversion coating forrned, e.g., chloride ions, which may induce white speçkin~ of any zinc-rich areas of the coated substrate. Irrespective of its actual source, the concentration in a working conversion coating forming aqueous liquid composition according to the invention, measured as its stoichiometric equivalent as pure hydroxylamine, preferably is at least, with increasing pl~r~,lcllce in the order given, 0.2, 0.5, 0.8, l .0, 1.1, 1.2, 1.3, 1.4, or 1.5 ppt and independ-W O 97/17480 PCTrUS96/17086 ently preferably is not more than, with increasing plcr~l~nce in the order given, 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 conversion coated according to this invention includes a portion that contains at least 45 % of al~ l l and/or a portion that contains 5 at least 85 % of zinc, a working conversion coating forming aqueous liquid composition according to the invention preferably includes optional simple and/or complex fluoride anions component (G); more preferably, if the substrate surface includes a portion that contains at least 85 % of zinc, at least part of the fluoride present is in the form of fluo-boric, fluosilicic, fluotitanic, and/or fluozirconic acids and their salts, most preferably 10 fluosilicic acid and/or fluosilicate ions.
Because of the competing complex-forming-and-dissociating equilibria in which fluoride can participate in a working conversion coating forming aqueous liquid compo-sition according to this invention that contains some deliberately added complex fluomet-allate and/or hydrofluoric acid, the plcr~lable concentrations for fluoride in such a com-position are specified in terms of "active free fluoride", as measured by means of a fluor-ide sensitive electrode and associated instrl-ment:~tion and methods that are described in U. S. Patents 3,350,284 and 3,619,300. Suitable ~a.dL~Is and instructions for using it are commercially available under the name LINEGUARD(~ l O lA Meter from the Parker ~mchem Division ("PAM") of Henkel Corp., Madison Heights, MI. "Active free fluori-20 de" as this term is used herein was measured relative to a 120E Activity Standard So-lution also commercially available from PAM. In brief, the fluoride sensitive electrode and the reference electrode provided with the LINEGUARD(~) 101 A Meter are both im-mersed in the noted Standard Solution and the millivolt meter reading is adjusted to 0 with a Standard Knob on the instrument, after waiting if necessary for any drift in read-25 ings to abate. The electrodes are then rinsed with deionized or distilled water, dried, andimmersed in the sample to be measured, which should be brought to the same temper-ature as the noted Standard Solution had when it was used to set the meter reading to 0.
The reading of the electrodes immersed in the sample is taken directly from the millivolt (hereinafter often abbreviated "mv" or "mV") meter on the instrument and converted to 30 ppm by comparison with the millivolt readings obtained with solutions of known free fluoride content, usually sodium or potassium fluoride solutions in water.
The free fluoride content of a working conversion coating forming aqueous liquid WO 97/17480 PCTrUS96/17086 composition according to the invention, when a surface including areas that are at least 45 % alll,.,i,,l~,.l is being treated, preferably is at least, with increasing preference in the order given, 100, 150, 200, 250, 300, 350, 375, or 400 ppm and independently preferably is not more than, with increasing ~rerelel1ce in the order given, 1200, 1000, 900, 800, 750, 725, 700, 675, 650, 625, or 600 ppm. If a surface including areas that are at least 85 % zinc but no areas that are at least 45 % alllminum is to be treated, the free fluoride content preferably is not more than, with increasing preference in the order given, 100, 75, 60, 45, 40, 35, 30, 25, 20, 15, or 10 ppm, but the total content of fluoborate, fluosili-cate, fluotitanate, and fluozirconate, which in~ s the stoichiometric equivalent as these ions of all corresponding acids and partially acidic salts added to the compositions, ir-respective of the actual degree of ionization existing in the composition, preferably is at least, with increasing p,~re~nce in the order given, 0.1, 0.3, 0.5, 0.7, 0.8, 0.9, 1.00, 1.10, 1.15, or 1.20 ppt and independently preferably is, primarily for reasons of economy and with increasing preference in the order given, not more than 3.0, 2.5, 2.0, 1.8, 1.6, 1.50, 1.45, 1.40, 1.35, or 1.30 ppt. Most preferably, the total amount of these complex fluoride anions is fluosilicate or its corresponding acid or acid salt. When the surfaces being treated are ferrous and do not include any areas that are predomin~ntly either al~-minllm or zinc, fluoride may be omitted altogether, and such omission is normally preferred for economic reasons. If any fluoride is present in the working compositions according to the invention for treating only ferrous substrates, the same preferences as noted above for the maximum amount of free fluoride activity in a composition for treating alumin-urn-free zinciferous surfaces apply.
In a working conversion coating forming aqueous liquid composition according to the invention, the Total Acid and Free Acid contents of the composition are preferably measured and controlled. These acid contents, consistent with general practice in the phosphating art, are ~re~,st:d herein in "points", by which is meant the millilit~rs ("ml") of 0.1 ~NaOH required to titrate a 10 ml aliquot sample, to a pH of 8.2 (e.g., with phe-nolphthalein indicator) for Total Acid and to a pH of 3.8 (e.g., with bromophenol blue indicator) for ~ree Acid.
In a working conversion coating forming aqueous liquid composition according to the invention, the content of Free Acid preferably is at least, with increasing prefer-ence in the order given, 0.1, 0.2, 0.3. 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.0 points and inde-.
pendently preferably is not more than, with increasing preference in the order given, 3.0, 2.5, 2.0, 1.8, 1.7, 1.6, or 1.5 points; and, independently, the content of Total Acid prefer-ably is at least, with increasing preference in the order given, 15, 16, 17, 18, 19, 20, or 21 points and independently preferably is not more than, with increasing preference in s the order given, 50, 40, 35, 32, 30, 29, or 28 points. The Free Acid and Total Acid con-tents can be adjusted into the ~.crcl.ed range, without disturbing the preferred values for other constituents of a conversion coating forming aqueous liquid composition according to the invention, by additions, to an otherwise satisfactory conversion coating forming aqueous liquid composition, of small amounts of strongly zllk~lin~ m~t~ri~l~ such as sodi-um and potassium hydroxides or strong acids such as nitric and sulfuric acids? as appro-priate for the direction in which it is desired to change the Free Acid and Total Acid con-tents, in a manner generally known to those skilled in the art.
Preferably make-up concentrate compositions according to this invention are single package liquid cunccllL ~les, i.e., are aqueous liquids that consist of water and each of components (A) through (G), as recited above for working compositions, that are de-sired in the working compositions to be prepared from the make-up concentrate composi-tions, along with any other ingredients desired in the working compositions, except pos-sibly for strong acids or alkalies that are not part of any of components (A) through (G) and are added to working compositions after ~ Lion thereof to slightly less than the final desired volume, in order to adjust the Free Acid and Total Acid contents therein as defined above. Preferably, all the components except water of a make-up concentrate composition according to the invention are present therein in a concentration such that the ratio of the concentration of each component in the make-up concentrate composi-tion to the concentration of the same component in the working composition that it is de-sired to prepare from the concentrate composition will be at least, with increasing prefer-ence in the order given, 5:1.0, 10:1.0, 20:1.0, 30:1.0, 40:1.0, or 50:1Ø
Preferably the conccl,ll~lcs are stable to storage in the temperature range from at least -20 to 50, or more preferably to 80, ~ C. Stability may conveniently be evaluated by measuring the free acid and total acid contents as described above. If these values have not changed after storage by more than 10 % of their value before storage, the con-centrate is considered storage stable. With increasing plcrcle,lce in the order given, the concentrates according to the invention will be storage stable as thus defined after stor-W O 97/17480 PCT~US96/17086 age for 1, 3, 10, 30, 60, or 200 days.
The actual conversion coating forming step in a process according to this invention preferably is performed at a temperature that is at least, with increasing preference in the order given, 35, 38, 41, 44, 46, or 48 ~C and independently preferably iS, primarily for reasons of economy, not more than 70, 65, 60, 55, 53, 51, or 50 ~C.
Primarily for reasons of economy, the time of contact between the metal surface being coated and a working composition according to the invention preferably is not greater than, with increasing ~ el,ce in the order given, 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 and adequately protective coating is formed within that time. Otherwise, a process according to this invention is preferably operated under the conditions conventional in the art for compositions that are otherwise like the compositions according to this invention, except for substit~lting a conventional amount of nitrite accelerator for all of the hydroxylamine, acrylate and/or methacrylate polyrner, and at least difunctional acids and/or hydroxyacids described above for compositions according to this invention. Furthermore, in a process according to the invention that includes other steps than zinc phosphate conversion coating with a composition as described above, the other steps preferably are conven-tional per se.
The practice of this invention may be further appreciated by consideration of the following, non-limiting, working exarnples and comparison examples.
General Processin~ Conditions The substrates used and their abbreviations as used in later tables are shown inTable I below. The ~ub~lldles 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 tr~ m~rk~ DEOXYLYTE(~), FIXODl!NE(~), or PARCO(I~ are commercially available from the Parker Amchem Division of Henkel Corp., Madison W O 97/17480 PCT~US96/17086 Table 1 Substrate Metal Type Abbreviation Cold rolled steel CRS
5One side electrogalvanized steel lEG
Hot dip galvanized steel HDG
Both sides electrogalvanized steel 2EG
Zinc-iron alloy Z-I
Table 2 rrocess ActionFluid Used Temp., ~C Time, Sec.
SprayPrimaryCleaning21 g/LofPARCO@) 49 90 Cleaner 1502 in water Spray Rinse Tap Water 49 30 Activation FIXODINE~) Z-8 20-25 30 Conditioner, 11 ppm Ti Phosphating See latertables 49 10, 120*
Spray Rinse Tap Water 20 - 25 30 Postrinsing 0.25 % DEOXYLYTE~ 20-25 30 54 NC Postrinse in water SprayRinse Deionized water 20-25 15 Footnote for Table 2 *The entire panel was dipped into the ph~sphz~ting composition for 10 seconds. Then the top half of the panel was withdrawn. The bottom half remained immersed for a total of 120 seconds, and the entire panel was then withdrawn from contact with the phosphating composition.
Abbreviations for Table 2 Temp. = Temperature; Sec. = Seconds.
Heights, Michigan and/or Henkel Metallchimie, Dusseldorf, Germany, together with di-rections for using them as noted below.
W O 97/17480 PCT~US96/17086 Workin~ Phosphatin~ Compositions The most important components of several working compositions are shown in Table 3; the balance not shown in the table is water or counterions, the latter being pre-dominzln~ly sodiurn to serve as counterions to a substantial fraction of the phosphate content. Aqueous sodium hydroxide solution was used when needed to lower free acid content. Nitric acid was added in small quantities as the concentration of citrate was in-creased, to avoid unwanted decreases in free acid content without chz~ngin~ the zinc to phosphate ratio. 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 was added as hydrofluoric acid. Free fluoride contents preceded by the "less than" sign (<) 10 were measured in the same way, but also mean that no hydrofluoric acid or other known source of uncomplexed fluoride was deliberately added; the free fluoride activity presum-ably arose from 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 AcusolTM 410 polymer solution in water, a product commercially supplied by Rohm 15 & Haas Co. and reported by its supplier to contain 54 % by weight of a homopolymer of acrylic acid in which 20 number % of the carboxylic moieties are neutralized with sodium hydroxide, the polymer in the all acid form having a weight average molecular weight of 1000 and a number average molecular weight of 650.
Table 3 Ingredient and Amount of Ingredient in Composition FY5~ r~ Number:
C L ~
Unit 1 2 3 4 5 6 7 8 9 10 Zn+2 ions, ppt 1.1 1.1 1.11.1 1.05 1.1 1.1 1.01 Po4-3 ions, ppt 14 14 14 14 13.7 14 14 13.7 14 14 Mn+2 ions, ppt 0.8 0.8 0.80.8 0.81 0.8 0.8 0.84 0.8 0.8 Nj+2 ions, ppt 0.8 0.8 0.80.8 0.78 0.8 0.8 0.8 0.8 0.8 Sodiumcitrate Slt.Slt. Slt. Slt. Slt. Slt. Slt. Slt. Slt. Slt.
dihydrate, ppt (NH3OH)2SO4,1.7 1.7 1.7 1.71.7 1.7 1.7 1.7 1.7 1.7 ppt Free Acid, 1.5 1.7 1.0 1.01.0 1.0 1.5 1.0 0.7 0.6 points Total Acid, 27 28 27 21 25 27 27 26 27 27 points Acrylate 10 10 10 25 25 25 25 50 50 50 polymer, ppm H2SiFo, ppt1.25 1.251.25 1.25 1.25 1.25 1.25 1.25 1.25 1.25 Free F- 690 690 690 <25<25 680 680 670 670 670 activity, ppm Abbreviation for Table 3 Slt. = See later table(s).
The citrate concentrations in the working phosphating compositions and the resulting coating weights and crystal sizes are sho~,-vn in Tables 4 - 11.
Table 4: RESULTS WITH 10 PPM OF ACRYLATE POLYMER ON CRS SUBSTRATES
Comp. Citrate Conc. Coating Weights,C~ystal Size, Other # g/m2 ~ Observa-tions Top Bottom 0.10 1.10 2.62 8- 10 SRD
0.20 1.17 2.83 5 - 8 SRD
2 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
Additional Abbreviations for Table 4 (See notes for previous tables and main text for others) Comp. # = Composition Number (from Table 3); Conc. = Concentration, g/m2 = grams per sq~are meter; ~1 = micrometres; SRD = Surface rust and dusting observable after phosphating;
DVSR = Dusting and very slight surface rust observable after phosphating; D = Dusting but no rust observable after pho~h~tin~.
-W O 97/17480 PCT~US96/17086 Table 5: ~ESULTS WITH 10 PPM OF ACRYLATE POLYMER ON lEG SUBSTl~ATES
Comp.Citrate Coating Weight, g/m2 Crystal Size, ~ Other # Conc. OSS OGS OSS OGS Obser-Top Bottom Top Bottom 0.10 1.12 3.01 2.88 2.82 5 - 10 - 10 D
0.20 0.88 2.80 2.83 2.97 5- 10 ~ 8 D
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 S 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 3 D
Additional Abbreviations for Table 5 (See notes for previous tables and main text for others) OSS = On steel side; OGS = On galvanized side; N.m. = Not measured.
Table 6: RESULTS WITH 10 PPM OF ACRYLATE POLYMER ON OTHER SUBSTRATES
On HDG Substrate On 2EG Substrate On ~I Substrate Coat. Wt., g/m2 Crystal Coat. Wt., g/m2 C~ystal Coat. Wt., g/m2 Crystal Size ~1 Size, ~1 Size, Top Bottom ~r- Top Bottom Top Bottom 2.96 2.84 10 3.08 2.52 5 2.13 4.10 15 - 20 Additional Abbreviation for Table 6 (See notes for previous tables and main text for others) Coat. Wt. = Coating Weight General Note for Table 6 The phosphating composition used for all results in this table was Number 3 from Table 3 with 1.00 ppt of citrate. No surface rust or dusting of the coating was observed.
WO 97/17480 PCT~US96/17086 Table 7: RESULTS WITH 25 PPM OF ACRYLATE POLYMER ON CRS SUBSTRATES
Comp. Citrate Conc. CoatingWeights,C~ystal Size, Other m2 ~ O~5~
tions Top Bottom 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 0.342.1 ~0.7 3 - 6 DVSR
Footnote for Table 7 *Comparison example, not according to the invention.
WO 97tl7480 PCT/US96/17086 Table 8: RESULTS WITH 25 PPM OF ACRYLATE POLYMER ON lEG SUBSTRATES
Comp. #Citrate CoatingWeight, glm2 C~ystal Other Conc. Size, ~, Obser-OSS OGS OGS vations Top Bottom Top Bottom 4 0.00* 0.66* 2.24* 2.51* 3.28*10- 15* SRD*
4 0.10 1.09 4.47 2.73 3.148- 10 D
4 0.20 1.04 4.73 3.29 3.108- 10 D
4 0.30 0.91 4.06 3.29 3.155 - 8 D
0.30 1.36 3.18 2.76 2.905 - 8 D
0.40 1.34 3.19 2.85 2.965 - 8 D
0.50 1.52 3.18 2.78 3.045 - 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
Footnote for Table 8 *Comparison exarnple, not according to the invention.
Table 9: RESULTS WITH 25 PPM OF ACRYLATE POLYMER ON OTHER SUBSTRATES
Comp. #Citrate On HDG On 2EG On ZI
Conc. Substrate SubstrateSubstrate Coat. Wt., g/m2 Coat. Wt., g/m2 Coat. Wt., glm2 Top Bottom Top Bottom Top Bottom 4 0.30 1.68 3.04 3.13 2.930.41 3.49 7 0.50 3.38 2.81 3.25 3.270.64 4.66 General Note for Table 9 Surface dusting but no rust after phosphating was observed for both exarnples in this table.
W O 97/17480 PCT~US96/17086 Table 10: RESULTS WITH 50 PPM OF ACRYLATE POLYMER ON CRS SUBSTRATES
Comp. Citrate Conc. Coating Weights, Clystal Size, Other # g/m2 ~u Observa-tions TopBottom 8 0.10 1.061.87 8- 10 DVSR
9 0.10 0.582.81 8- 10 SRD
0.15 1.054.80 8- 10 SRD
9 0.20 0.933.64 8- 10 SRD
Table 11: RESULTS WITH 50 PPM OF ACRYLATE POLYMER ON lEG SUBSTRATES
Comp. Citrate Coating Weight, g/m2 Clystal Size, ~ Other # Conc. OSS OGS OSS OGS Obser-Top Boffom Top Bottom 8 0.10 0.48 2.62 3.11 4.2110 15 D
9 0. 1 0 1 .04 4.7 1 4.02 4.208 -1 0 1 5 D
0.15 0.91 3.02 3.84 4.278- 10 10 D
9 0.20 0.69 3.75 3.79 3.84 8 5 D
COATING COMPOSITION AND PROCESS
BACKGROUND OF THE INVENTION
Field of the Invention This invention relates to compositions and processes for depositing zinc phos-phate cont~ining conversion co~ting~ on metal surfaces, particularly the surfaces of iron, steel, zinc-iron alloy, galvanized steel and other predominantly zinciferous surfaces, and al.l",;"~l", anditsalloysthatcontainatleast45 %byweightofalllminllm Theinventionparticularly relates to such compositions and processes that produce, at a high coating speed, a conversion coating with a very fine average crystal size.
Statement of Related Art The general process of zinc phosphate conversion coating is well known in the art. See, e.g., M. ~.qm~her, "Ecologically Safe Pretre~tment~ of Metal Surfaces", Hen-kel-Referate 30 (1994), pp. 138 - 143, which, except to the extent that it may be contrary to any explicit st~tem~nt herein, is hereby incol~uldl~d herein by reference. In brief, con-tact of active metals with aqueous acidic compositions cont~inin~ zinc and phosphate ions results in the deposition on the active metal sllrf~es of a conversion coating con-taining zinc phosphate. If the active metal is ferrous, iron phosphates are usually includ-ed in the coating, and in modern practice nickel andtor m~ng~nese are often included in the coating composition and thereby in the coating formed. In order to speed the process and improve the uniformity of the coating, it is c~Lolll~y to include in the coating com-position a component called an "accelerator" that does not usually become incorporated into the coating formed. Typical widely used accelerators include nitrate, nitrite, and chlorate ions, water soluble niLloal~ollldLic organic compounds such as p-nitrobenzene sul-fonic acid, and hydroxylamine (the latter almost always in the form of salts or complex-es).
~, 25 A frequently observed problem with prior art conversion coatings, particularly on cold rolled steel, has been the production of small rusty spots on areas of the treated ~ul~Lldl~ metal that were blocked from full contact with the conversion coating forming liquid composition by small gas bubbles that were formed andtor trapped on the substrate WO 97/17480 PC~r~US96/17086 surface during the conversion coating treatment process. It is believed that the water vapor inside such bubbles is sufficient to cause rusting before the desired formation of a protective conversion coating can progress sufficiently far to prevent rust, and once a rusty spot has formed, it can not usually be covered satisfactorily later even by full con-5 tact with the conversion coating forming liquid composition.
DF!~CRIPTION OF THE INVENTION
Object of the Invention One object of this invention is to provide a composition and process for phosphat-ing that will provide a protective conversion coating with a more refined crystal size than 10 is now generally achieved by zinc phosphating. Another ~It~rn~tive or concurrent object is to provide a zinc phosphating composition and process that will form a high quality protective conversion coating during a brief contact time with a metal substrate to be coated, so that coil coating and other continuous phosphating operations can be run at higher speeds. Still another concurrent or alternative object is to avoid the formation of 5 surface rust on small areas of the treated substrate that are blocked by gas bubbles from full contact with the conversion coating solution. Other objects will be apparent from the description below.
General Principles of Description Except in the claims and the operating examples, or where otherwise expressly 20 indicated, all numerical quantities in this description indicating amounts of material or conditions of reaction and/or use are to be understood as modified by the word "about"
in describing the broadest scope of the invention. Practice within the numerical limits stated is generally preferred, however. Also, throughout the description and claims, unless expressly stated to the contrary: percent, "parts of', and ratio values are by weight;
25 the description of a group or class of materials as suitable or pler~ d for a given purpose in connection with the invention implies that mixtures of any two or more of the members of the group or class are equally suitable or ~ler~ d; description of constituents in chemical terms refers to the con~tit~l.ont~ at the time of addition to any combination specified in the description, and does not necessarily preclude chemical 30 interactions among the constituents of a mixture once mixed; specification of materials in ionic form implies the presence of sufficient counterions to produce electrical neutrality for the composition as a whole; any counterions thus implicitly specified should preferably be selected from among other con~tit lent~ explicitly specified in ionic form, to the extent possible; otherwise such counterions may be freely selected, except for avoiding counterions that act adversely to the objects of the invention; the terms ~ "molecule" and "mole" and their gr~mm~tiç~l variations may be applied to ionic, elem~nt~l, or any other type of chemical entities defined by the number of atoms of each type present therein, as well as to substances with well-defined neutral molecules; the first definition of an acronym or other abbreviation applies to all subsequent uses herein of the saTne abbreviation; and the term "polymer" includes "oligomer", "homopolymer", "copolyrner", "terpolymer", and the like.
Sllmm~ry of the Invention It has been found that one or more of the objects stated above for the inventioncan be achieved by the use of a conversion coating forming aqueous liquid composition that comprises, preferably consists eesçnti~lly of, or more preferably consists of, water and:
15 (A) dissolved zinc cations;
(B) dissolved phosphate anions;
(C) a dissolved component selected from the group consisting of organic acids and anions thereof that (i) contain at least two moieties per molecule that are selected from the group consisting of carboxyl and carboxylate moieties and hydroxyl moieties that are not part of a carboxyl moiety and (ii) do not contain more than 12 carbon atoms per molecule; and (D) a dissolved component selected from the group con~i~ting of polymer molecules which contain more than 12 atoms per molecule and in which at least 50 % of the polymer molecule is made up of one or more moieties with one of the formulas:
-(CHz-CH)- or -(CHz-C)-, C=O C=O
1 l OM OM
where M l~.ese~ a hydrogen atom, a monovalent cation, or a monovalent frac-tion of a polyvalent cation; and, optionally, (E) a component of dissolved metal cations selected from the group consisting of W O 97/17480 PCT~US96/17086 metal cations, exclusive of zinc cations, with a charge of at least two;
(F) a component of dissolved accelerator molecules, exclusive of any molecules that are part of any of the prececling components; and (G) a component of dissolved simple and/or complex fluoride anions, exclusive of any anions that are part of any of the preceAin~ components.
Various embo-liment~ of the invention include working compositions for direct use in treating metals, make-up conr~ntr~t~s from which such working compositions can be ~l~paled by dilution with water, replenisher concentrates suitable for m~int~inin~ op timum performance of working compositions according to the invention, processes for treating metals with a composition according to the invention, and extended processes including additional steps that are conventional per se, such as cleaning, activation with titaniurn phosphate sols (Jernstedt salts), rinsing, and subsequent painting or some similar overcoating process that puts into place an organic binder cont~ining protective coating over the metal surface treated according to a ,l~lv~l embodiment of the invention. Art-icles of manufacture including surfaces treated according to a process of the invention are also within the scope of the invention.
Description of Preferred Embodiments For a variety of reasons, it is sometimes l~lc;rcll~,d that compositions according to the invention as defined above should be sub~ lly free from many ingredients used in compositions for similar purposes in the prior art. Specifically, when maximum stor-age stability of a concentrate is desired, it is preferred, with increasing ~l~r~,.ellce in the order given, independently for each preferably minimi7ed component listed 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: nitrite, chlorate, chloride, bromide, iodide, organic compounds cont~inin~ nitro groups, hexavalentchromium, m~n~nPse in a valence state of four or greater, ferricyanide; ferrocyanide, and pyrazole compounds. ln contrast, in working solutions, accelerator components such as those included in this list have no known detrimental effect (except for the danger of white specking zinciferous surfaces treated with compositions that contain too much chloride, which is formed in situ from chlorate), but are generally not needed, and their absence may therefore be preferred for economic reasons.
The dissolved zinc cations required for nPcPc~ry component (A) may be obtained WO 97/17480 PCTrUS96/17086 from any soluble zinc salt or from zinc metal itself or any zinc co~ g compound that reacts with aqueous acid to form dissolved zinc cations. Normally ~lcrcll~,d sources, largely for economic reasons, are zinc oxide, zinc carbonate, and zinc dihydrogen phos-phate. In a working conversion coating forming aqueous liquid composition according 5 to the invention, the concentration of dissolved zinc cations preferably is at least, with increasing plcrclcnce in the order given, 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 parts per thousand (hereinafter usually abbreviated as "ppt") and independently preferably is not more than, with increasing plt;r~cllce in the order given, 2.0, 1.8, 1.6, 1.4, 1.30, 1.20, l.lS, or 1.10 ppt.
The dissolved phosphate ions that constitute necessary component (B) also may be obtained from a variety of sources as known in the general phosphate conversion coat-ing art. Because of a preference noted below for a substantial amount of total acid in a working conversion coating forming aqueous liquid composition according to the inven-tion, normally much of the phosphate ion content will preferably be supplied by phos-phoric acid added to the composition, and the stoichiometric equivalent as phosphate ions of all undissociated phosphoric acid and all its anionic ionization products in solution, along with the stoichiometric equivalent as phosphate ions of any dihydrogen phosphate, monohydrogen phosphate, or completely neutralized phosphate ions added to the compo-sition in salt form, are to be understood as forming part of component (B), irrespective of the actual degree of ionization that exists in the composition. In a working conversion coating forming aqueous liquid composition according to the invention, the concentration of component (B) preferably is at least, with increasing preference in the order given, 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 independently preferably is not more than, with increasing plefe,~llce in the order given, 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 compon-ent (A) to the concentration of component (B) in a conversion coating forming aqueous liquid composition according to the invention, whether working or concentrate, preferab-ly iS at least, with increasing preference in the order given, 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 independently pref-erably is not more than, with increasing l~lcfclence in the order given, 1.0:5.0, 1.0:6.0, W O 97/17480 PCT~US96/17086 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 carboxyl(ate) moiety and one hydroxyl moiety that is not part of any carboxyl(ate) moiety, more preferably from the group con~icting of citric acid, gluconic acid, and heptogluconic acid and the water soluble salts of all of these acids, most preferably from citric acid and its water soluble salts. Independently, the concentration of component (C) in a working conversion coating forming aqueous liquid composition according to the invention preferably is at least, with increasing preference 0 in the order given, 0.1, 0.2, 0.3, or 0.4 millimoles per kilogram of total composition (hereinafter usually abbreviated "mM/kg") and, if small crystal size of the conversion coating formed is desired, more preferably is at least, with increasing preference in the order given, 1.0, 1.2, or 1.6 mM/kg; if small crystal size of the conversion coating formed is desired and the concentration of component (D) is near the lower end of its preferred ranges as further described below, the con~entr~tion of component (C) in a working con-version coating forming aqueous liquid composition according to the invention still more preferably is at least 3.5 mM/kg. Independently, primarily for reasons of economy, the concentration of component (C) in a working composition according to the invention preferably is not more than, with increasing l~lcrelGllce in the order given, 50, 25, lS, 10, 7,5, 4.5, or 4.1 mM/kg, and if larger crystal size is acceptable, more preferably is not greater than, with increasing ~rt;rc~ ce in the order given, 3.2, 3.0, 2.8, 2.5, 2.2,1.9, or 1.7 mM/kg.
Component (D) preferably is selected from polymer molecules in which at least, with increasing p~crclcnce in the order given, 60, 70,75,80, 85, 90, or 95 % of the mole-2s cule consists of one or more moieties with one of the formulas:
fH3 -(CH2-fH)- or -(CH2-f)-, f=o f=o OM OM
more preferably the formula shown on the left, or in other words, acrylate rather than methacrylate moieties. Independently, with increasing ~ler~rcllce in the order given, at W O 97/17480 PCT~US96/17086 least 30, 50, 60, 70, or 80 nurnber percent of these acrylate and methacrylate moieties in component (D) have hydrogen rather than any other atom or cation in the position in the formula indicated by the symbol "M" in the formulas shown. Independently of bothother plcrc,cl,ces, the weight average molecular weight of the polymers in the component 5 (D), measured as its stoichiometric equivalent when all the acrylate and methacrylate moieties are in an acid form, preferably is at least, with increasing pLc;rcl~ ce in the order given, at least 400, 500, 600, 700, 750, 800, 850, 900, 950, or 975 and independently preferably is not more than, with increasing ~lcrclcnce in the order given, 10,000, 9000, 8000, 7000, 6000, 5000, 4500, 4000, 3500, 3000, 2500, 2000, 1700, 1400, 1300, 1250, 1200, 1 150, 1 100, or 1050. Also, independently of the other preferences for component (D), the concentration of component (D) in a working conversion coating forming aque-ous liquid composition according to the invention preferably is at least 5, 10, 15, 20, 22, or 24 ppm and independently preferably is not more than 300, 200, 100, 85, 75, 65, or 55 ppm and, unless the concentration of component (C) is not more than 0.4 mM/kg, 15 more preferably is not more than, with increasing preference in the order given, 45, 35, 30, or 26 ppm.
If high corrosion resistance after application of an organic protective coating to a metal substrate, subsequent to forming a conversion coating thereon by cont~cfinP: the substrate with a working conversion coating forming aqueous liquid composition accord-ing to the invention, is desired, as it usually is, a working conversion coating formingaqueous liquid composition according to the invention preferably contains one or more metal ions selected from optional component (E). Examples of preferred combinations of zinc ions with metal ions of component (E) in a working conversion coating forming aqueous liquid composition according to the invention are: Zn and Mn; Zn, Mn, and Co;
25 Zn, Mn, and Cu; Zn and Cu; Zn, Co, and Cu; and Zn, Mn, and Ni. It is especially pre-ferred for a working conversion coating forming aqueous liquid composition according to the invention to contain, as at least part of optional component (E), dissolved divalent m~n~nese cations in a concentration that preferably is at least, with increasing prefer-ence in the order given, 100, 200, 300, 400, 500, 550, 600, 650, 700, 750, 800, 825, or 30 835 ppm and independently preferably is, primarily for reasons of economy, not more than, with h~ ca,h~g ~,crt;,cllce in the order given, 4000, 3000, 2000, 1500, 1400, 1300, 1250, 1200, 1150, 1100, 1050, 1000, 950, or 900 ppm. Also, independently ofthe prefer-W O 97/17480 PCT~US96/17086 ences for m~n~n.oce as noted, it is especially preferred for a working conversion coating forming aqueous liquid composition according to the invention to include, as at least part of optional component (E), dissolved divalent nickel cations in a concentration that pref-erably is at least, with increasing preference in the order given, 100, 200, 300, 400, 500, 550, 600, 650, 700, 750, 765, 785, or 790 ppm and independently preferably is, primarily for reasons of economy, not more than, with increasing preference in the order given7 4000, 3000, 2000, 1500, 1400, 1300, 1250, 1200, 1150, 1100, 1050, 1000, 950, 900, or 850 ppm.
Independently of other pr~fe~ ces, the ratio of the concentration of zinc cations to the sum of the concentrations of m~nganese and nickel cations in a conversion coating forming aqueous liquid composition according to the invention preferably is at least, with increasingpl~ ce in the order given,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 and independently preferably is not more than, with increasingpreferenceintheordergiven, 1.0:0.2, 1.0:0.4, 1.0:0.6, 1.0:0.8, l.0:1.0, l.0:1.1, s 1.0:1.2, 1.0:1.3, 1.0:1.4, or 1.0:1.5. Independently, when both m~n~nese and nickel are present in a conversion coating forming aqueous liquid composition according to the in-vention, the ratio of m~ng7ln~se to nickel preferably is at least, with increasing plerelellce in the order given, 1.0:2.0, 1.0:1.7, 1.0: 1.5, 1.0:1.3, 1 .0 : 1.2, 1.0: 1.1, or 1.0: 1.0 and inde-pendently preferably is not more than, with increasing ~rerclcnce in the order given, 1.0:0.2, 1.0:0.5, 1.0:0.7, 1.0:0.8, or l.0:0.9.
A working conversion coating forming aqueous liquid composition according to the invention preferably includes, as at least part, and more preferably as all, of optional component (F) a dissolved source of hydroxylamine. The source may be hydroxylamine itself, but most users prefer to avoid potential hazards from hzln~lling pure hydroxylamne, So that a salt or complex of hydroxylamine is generally preferred. Hydroxylamine sul-fate, which has the chemical formula (NH30H)2SO4 is particularly preferred for economy and lack of any ions that may be deleterious to the quality of conversion coating forrned, e.g., chloride ions, which may induce white speçkin~ of any zinc-rich areas of the coated substrate. Irrespective of its actual source, the concentration in a working conversion coating forming aqueous liquid composition according to the invention, measured as its stoichiometric equivalent as pure hydroxylamine, preferably is at least, with increasing pl~r~,lcllce in the order given, 0.2, 0.5, 0.8, l .0, 1.1, 1.2, 1.3, 1.4, or 1.5 ppt and independ-W O 97/17480 PCTrUS96/17086 ently preferably is not more than, with increasing plcr~l~nce in the order given, 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 conversion coated according to this invention includes a portion that contains at least 45 % of al~ l l and/or a portion that contains 5 at least 85 % of zinc, a working conversion coating forming aqueous liquid composition according to the invention preferably includes optional simple and/or complex fluoride anions component (G); more preferably, if the substrate surface includes a portion that contains at least 85 % of zinc, at least part of the fluoride present is in the form of fluo-boric, fluosilicic, fluotitanic, and/or fluozirconic acids and their salts, most preferably 10 fluosilicic acid and/or fluosilicate ions.
Because of the competing complex-forming-and-dissociating equilibria in which fluoride can participate in a working conversion coating forming aqueous liquid compo-sition according to this invention that contains some deliberately added complex fluomet-allate and/or hydrofluoric acid, the plcr~lable concentrations for fluoride in such a com-position are specified in terms of "active free fluoride", as measured by means of a fluor-ide sensitive electrode and associated instrl-ment:~tion and methods that are described in U. S. Patents 3,350,284 and 3,619,300. Suitable ~a.dL~Is and instructions for using it are commercially available under the name LINEGUARD(~ l O lA Meter from the Parker ~mchem Division ("PAM") of Henkel Corp., Madison Heights, MI. "Active free fluori-20 de" as this term is used herein was measured relative to a 120E Activity Standard So-lution also commercially available from PAM. In brief, the fluoride sensitive electrode and the reference electrode provided with the LINEGUARD(~) 101 A Meter are both im-mersed in the noted Standard Solution and the millivolt meter reading is adjusted to 0 with a Standard Knob on the instrument, after waiting if necessary for any drift in read-25 ings to abate. The electrodes are then rinsed with deionized or distilled water, dried, andimmersed in the sample to be measured, which should be brought to the same temper-ature as the noted Standard Solution had when it was used to set the meter reading to 0.
The reading of the electrodes immersed in the sample is taken directly from the millivolt (hereinafter often abbreviated "mv" or "mV") meter on the instrument and converted to 30 ppm by comparison with the millivolt readings obtained with solutions of known free fluoride content, usually sodium or potassium fluoride solutions in water.
The free fluoride content of a working conversion coating forming aqueous liquid WO 97/17480 PCTrUS96/17086 composition according to the invention, when a surface including areas that are at least 45 % alll,.,i,,l~,.l is being treated, preferably is at least, with increasing preference in the order given, 100, 150, 200, 250, 300, 350, 375, or 400 ppm and independently preferably is not more than, with increasing ~rerelel1ce in the order given, 1200, 1000, 900, 800, 750, 725, 700, 675, 650, 625, or 600 ppm. If a surface including areas that are at least 85 % zinc but no areas that are at least 45 % alllminum is to be treated, the free fluoride content preferably is not more than, with increasing preference in the order given, 100, 75, 60, 45, 40, 35, 30, 25, 20, 15, or 10 ppm, but the total content of fluoborate, fluosili-cate, fluotitanate, and fluozirconate, which in~ s the stoichiometric equivalent as these ions of all corresponding acids and partially acidic salts added to the compositions, ir-respective of the actual degree of ionization existing in the composition, preferably is at least, with increasing p,~re~nce in the order given, 0.1, 0.3, 0.5, 0.7, 0.8, 0.9, 1.00, 1.10, 1.15, or 1.20 ppt and independently preferably is, primarily for reasons of economy and with increasing preference in the order given, not more than 3.0, 2.5, 2.0, 1.8, 1.6, 1.50, 1.45, 1.40, 1.35, or 1.30 ppt. Most preferably, the total amount of these complex fluoride anions is fluosilicate or its corresponding acid or acid salt. When the surfaces being treated are ferrous and do not include any areas that are predomin~ntly either al~-minllm or zinc, fluoride may be omitted altogether, and such omission is normally preferred for economic reasons. If any fluoride is present in the working compositions according to the invention for treating only ferrous substrates, the same preferences as noted above for the maximum amount of free fluoride activity in a composition for treating alumin-urn-free zinciferous surfaces apply.
In a working conversion coating forming aqueous liquid composition according to the invention, the Total Acid and Free Acid contents of the composition are preferably measured and controlled. These acid contents, consistent with general practice in the phosphating art, are ~re~,st:d herein in "points", by which is meant the millilit~rs ("ml") of 0.1 ~NaOH required to titrate a 10 ml aliquot sample, to a pH of 8.2 (e.g., with phe-nolphthalein indicator) for Total Acid and to a pH of 3.8 (e.g., with bromophenol blue indicator) for ~ree Acid.
In a working conversion coating forming aqueous liquid composition according to the invention, the content of Free Acid preferably is at least, with increasing prefer-ence in the order given, 0.1, 0.2, 0.3. 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.0 points and inde-.
pendently preferably is not more than, with increasing preference in the order given, 3.0, 2.5, 2.0, 1.8, 1.7, 1.6, or 1.5 points; and, independently, the content of Total Acid prefer-ably is at least, with increasing preference in the order given, 15, 16, 17, 18, 19, 20, or 21 points and independently preferably is not more than, with increasing preference in s the order given, 50, 40, 35, 32, 30, 29, or 28 points. The Free Acid and Total Acid con-tents can be adjusted into the ~.crcl.ed range, without disturbing the preferred values for other constituents of a conversion coating forming aqueous liquid composition according to the invention, by additions, to an otherwise satisfactory conversion coating forming aqueous liquid composition, of small amounts of strongly zllk~lin~ m~t~ri~l~ such as sodi-um and potassium hydroxides or strong acids such as nitric and sulfuric acids? as appro-priate for the direction in which it is desired to change the Free Acid and Total Acid con-tents, in a manner generally known to those skilled in the art.
Preferably make-up concentrate compositions according to this invention are single package liquid cunccllL ~les, i.e., are aqueous liquids that consist of water and each of components (A) through (G), as recited above for working compositions, that are de-sired in the working compositions to be prepared from the make-up concentrate composi-tions, along with any other ingredients desired in the working compositions, except pos-sibly for strong acids or alkalies that are not part of any of components (A) through (G) and are added to working compositions after ~ Lion thereof to slightly less than the final desired volume, in order to adjust the Free Acid and Total Acid contents therein as defined above. Preferably, all the components except water of a make-up concentrate composition according to the invention are present therein in a concentration such that the ratio of the concentration of each component in the make-up concentrate composi-tion to the concentration of the same component in the working composition that it is de-sired to prepare from the concentrate composition will be at least, with increasing prefer-ence in the order given, 5:1.0, 10:1.0, 20:1.0, 30:1.0, 40:1.0, or 50:1Ø
Preferably the conccl,ll~lcs are stable to storage in the temperature range from at least -20 to 50, or more preferably to 80, ~ C. Stability may conveniently be evaluated by measuring the free acid and total acid contents as described above. If these values have not changed after storage by more than 10 % of their value before storage, the con-centrate is considered storage stable. With increasing plcrcle,lce in the order given, the concentrates according to the invention will be storage stable as thus defined after stor-W O 97/17480 PCT~US96/17086 age for 1, 3, 10, 30, 60, or 200 days.
The actual conversion coating forming step in a process according to this invention preferably is performed at a temperature that is at least, with increasing preference in the order given, 35, 38, 41, 44, 46, or 48 ~C and independently preferably iS, primarily for reasons of economy, not more than 70, 65, 60, 55, 53, 51, or 50 ~C.
Primarily for reasons of economy, the time of contact between the metal surface being coated and a working composition according to the invention preferably is not greater than, with increasing ~ el,ce in the order given, 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 and adequately protective coating is formed within that time. Otherwise, a process according to this invention is preferably operated under the conditions conventional in the art for compositions that are otherwise like the compositions according to this invention, except for substit~lting a conventional amount of nitrite accelerator for all of the hydroxylamine, acrylate and/or methacrylate polyrner, and at least difunctional acids and/or hydroxyacids described above for compositions according to this invention. Furthermore, in a process according to the invention that includes other steps than zinc phosphate conversion coating with a composition as described above, the other steps preferably are conven-tional per se.
The practice of this invention may be further appreciated by consideration of the following, non-limiting, working exarnples and comparison examples.
General Processin~ Conditions The substrates used and their abbreviations as used in later tables are shown inTable I below. The ~ub~lldles 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 tr~ m~rk~ DEOXYLYTE(~), FIXODl!NE(~), or PARCO(I~ are commercially available from the Parker Amchem Division of Henkel Corp., Madison W O 97/17480 PCT~US96/17086 Table 1 Substrate Metal Type Abbreviation Cold rolled steel CRS
5One side electrogalvanized steel lEG
Hot dip galvanized steel HDG
Both sides electrogalvanized steel 2EG
Zinc-iron alloy Z-I
Table 2 rrocess ActionFluid Used Temp., ~C Time, Sec.
SprayPrimaryCleaning21 g/LofPARCO@) 49 90 Cleaner 1502 in water Spray Rinse Tap Water 49 30 Activation FIXODINE~) Z-8 20-25 30 Conditioner, 11 ppm Ti Phosphating See latertables 49 10, 120*
Spray Rinse Tap Water 20 - 25 30 Postrinsing 0.25 % DEOXYLYTE~ 20-25 30 54 NC Postrinse in water SprayRinse Deionized water 20-25 15 Footnote for Table 2 *The entire panel was dipped into the ph~sphz~ting composition for 10 seconds. Then the top half of the panel was withdrawn. The bottom half remained immersed for a total of 120 seconds, and the entire panel was then withdrawn from contact with the phosphating composition.
Abbreviations for Table 2 Temp. = Temperature; Sec. = Seconds.
Heights, Michigan and/or Henkel Metallchimie, Dusseldorf, Germany, together with di-rections for using them as noted below.
W O 97/17480 PCT~US96/17086 Workin~ Phosphatin~ Compositions The most important components of several working compositions are shown in Table 3; the balance not shown in the table is water or counterions, the latter being pre-dominzln~ly sodiurn to serve as counterions to a substantial fraction of the phosphate content. Aqueous sodium hydroxide solution was used when needed to lower free acid content. Nitric acid was added in small quantities as the concentration of citrate was in-creased, to avoid unwanted decreases in free acid content without chz~ngin~ the zinc to phosphate ratio. 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 was added as hydrofluoric acid. Free fluoride contents preceded by the "less than" sign (<) 10 were measured in the same way, but also mean that no hydrofluoric acid or other known source of uncomplexed fluoride was deliberately added; the free fluoride activity presum-ably arose from 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 AcusolTM 410 polymer solution in water, a product commercially supplied by Rohm 15 & Haas Co. and reported by its supplier to contain 54 % by weight of a homopolymer of acrylic acid in which 20 number % of the carboxylic moieties are neutralized with sodium hydroxide, the polymer in the all acid form having a weight average molecular weight of 1000 and a number average molecular weight of 650.
Table 3 Ingredient and Amount of Ingredient in Composition FY5~ r~ Number:
C L ~
Unit 1 2 3 4 5 6 7 8 9 10 Zn+2 ions, ppt 1.1 1.1 1.11.1 1.05 1.1 1.1 1.01 Po4-3 ions, ppt 14 14 14 14 13.7 14 14 13.7 14 14 Mn+2 ions, ppt 0.8 0.8 0.80.8 0.81 0.8 0.8 0.84 0.8 0.8 Nj+2 ions, ppt 0.8 0.8 0.80.8 0.78 0.8 0.8 0.8 0.8 0.8 Sodiumcitrate Slt.Slt. Slt. Slt. Slt. Slt. Slt. Slt. Slt. Slt.
dihydrate, ppt (NH3OH)2SO4,1.7 1.7 1.7 1.71.7 1.7 1.7 1.7 1.7 1.7 ppt Free Acid, 1.5 1.7 1.0 1.01.0 1.0 1.5 1.0 0.7 0.6 points Total Acid, 27 28 27 21 25 27 27 26 27 27 points Acrylate 10 10 10 25 25 25 25 50 50 50 polymer, ppm H2SiFo, ppt1.25 1.251.25 1.25 1.25 1.25 1.25 1.25 1.25 1.25 Free F- 690 690 690 <25<25 680 680 670 670 670 activity, ppm Abbreviation for Table 3 Slt. = See later table(s).
The citrate concentrations in the working phosphating compositions and the resulting coating weights and crystal sizes are sho~,-vn in Tables 4 - 11.
Table 4: RESULTS WITH 10 PPM OF ACRYLATE POLYMER ON CRS SUBSTRATES
Comp. Citrate Conc. Coating Weights,C~ystal Size, Other # g/m2 ~ Observa-tions Top Bottom 0.10 1.10 2.62 8- 10 SRD
0.20 1.17 2.83 5 - 8 SRD
2 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
Additional Abbreviations for Table 4 (See notes for previous tables and main text for others) Comp. # = Composition Number (from Table 3); Conc. = Concentration, g/m2 = grams per sq~are meter; ~1 = micrometres; SRD = Surface rust and dusting observable after phosphating;
DVSR = Dusting and very slight surface rust observable after phosphating; D = Dusting but no rust observable after pho~h~tin~.
-W O 97/17480 PCT~US96/17086 Table 5: ~ESULTS WITH 10 PPM OF ACRYLATE POLYMER ON lEG SUBSTl~ATES
Comp.Citrate Coating Weight, g/m2 Crystal Size, ~ Other # Conc. OSS OGS OSS OGS Obser-Top Bottom Top Bottom 0.10 1.12 3.01 2.88 2.82 5 - 10 - 10 D
0.20 0.88 2.80 2.83 2.97 5- 10 ~ 8 D
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 S 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 3 D
Additional Abbreviations for Table 5 (See notes for previous tables and main text for others) OSS = On steel side; OGS = On galvanized side; N.m. = Not measured.
Table 6: RESULTS WITH 10 PPM OF ACRYLATE POLYMER ON OTHER SUBSTRATES
On HDG Substrate On 2EG Substrate On ~I Substrate Coat. Wt., g/m2 Crystal Coat. Wt., g/m2 C~ystal Coat. Wt., g/m2 Crystal Size ~1 Size, ~1 Size, Top Bottom ~r- Top Bottom Top Bottom 2.96 2.84 10 3.08 2.52 5 2.13 4.10 15 - 20 Additional Abbreviation for Table 6 (See notes for previous tables and main text for others) Coat. Wt. = Coating Weight General Note for Table 6 The phosphating composition used for all results in this table was Number 3 from Table 3 with 1.00 ppt of citrate. No surface rust or dusting of the coating was observed.
WO 97/17480 PCT~US96/17086 Table 7: RESULTS WITH 25 PPM OF ACRYLATE POLYMER ON CRS SUBSTRATES
Comp. Citrate Conc. CoatingWeights,C~ystal Size, Other m2 ~ O~5~
tions Top Bottom 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 0.342.1 ~0.7 3 - 6 DVSR
Footnote for Table 7 *Comparison example, not according to the invention.
WO 97tl7480 PCT/US96/17086 Table 8: RESULTS WITH 25 PPM OF ACRYLATE POLYMER ON lEG SUBSTRATES
Comp. #Citrate CoatingWeight, glm2 C~ystal Other Conc. Size, ~, Obser-OSS OGS OGS vations Top Bottom Top Bottom 4 0.00* 0.66* 2.24* 2.51* 3.28*10- 15* SRD*
4 0.10 1.09 4.47 2.73 3.148- 10 D
4 0.20 1.04 4.73 3.29 3.108- 10 D
4 0.30 0.91 4.06 3.29 3.155 - 8 D
0.30 1.36 3.18 2.76 2.905 - 8 D
0.40 1.34 3.19 2.85 2.965 - 8 D
0.50 1.52 3.18 2.78 3.045 - 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
Footnote for Table 8 *Comparison exarnple, not according to the invention.
Table 9: RESULTS WITH 25 PPM OF ACRYLATE POLYMER ON OTHER SUBSTRATES
Comp. #Citrate On HDG On 2EG On ZI
Conc. Substrate SubstrateSubstrate Coat. Wt., g/m2 Coat. Wt., g/m2 Coat. Wt., glm2 Top Bottom Top Bottom Top Bottom 4 0.30 1.68 3.04 3.13 2.930.41 3.49 7 0.50 3.38 2.81 3.25 3.270.64 4.66 General Note for Table 9 Surface dusting but no rust after phosphating was observed for both exarnples in this table.
W O 97/17480 PCT~US96/17086 Table 10: RESULTS WITH 50 PPM OF ACRYLATE POLYMER ON CRS SUBSTRATES
Comp. Citrate Conc. Coating Weights, Clystal Size, Other # g/m2 ~u Observa-tions TopBottom 8 0.10 1.061.87 8- 10 DVSR
9 0.10 0.582.81 8- 10 SRD
0.15 1.054.80 8- 10 SRD
9 0.20 0.933.64 8- 10 SRD
Table 11: RESULTS WITH 50 PPM OF ACRYLATE POLYMER ON lEG SUBSTRATES
Comp. Citrate Coating Weight, g/m2 Clystal Size, ~ Other # Conc. OSS OGS OSS OGS Obser-Top Boffom Top Bottom 8 0.10 0.48 2.62 3.11 4.2110 15 D
9 0. 1 0 1 .04 4.7 1 4.02 4.208 -1 0 1 5 D
0.15 0.91 3.02 3.84 4.278- 10 10 D
9 0.20 0.69 3.75 3.79 3.84 8 5 D
Claims (20)
1. An aqueous liquid composition of matter suitable either as such or after dilution with water for forming a phosphate conversion coating on a metal substrate by contact therewith, said composition comprising water and:
(A) a concentration of dissolved zinc cations;
(B) a concentration of dissolved phosphate anions;
(C) a concentration of a dissolved component selected from the group consisting of organic acids and anions thereof that (i) contain at least two moieties per molecule that are selected from the group consisting of carboxyl and carboxylatemoieties and hydroxyl moieties that are not part of a carboxyl group and (ii) donot contain more than 12 carbon atoms per molecule; and (D) a concentration of a dissolved component selected from the group consisting of polymer molecules which contain more than 12 atoms per molecule and in which at least 50 % of the polymer molecules is made up of one or more moieties with one of the general chemical formulas:
or where M represents a hydrogen atom, a monovalent cation, or a monovalent fraction of a polyvalent cation.
(A) a concentration of dissolved zinc cations;
(B) a concentration of dissolved phosphate anions;
(C) a concentration of a dissolved component selected from the group consisting of organic acids and anions thereof that (i) contain at least two moieties per molecule that are selected from the group consisting of carboxyl and carboxylatemoieties and hydroxyl moieties that are not part of a carboxyl group and (ii) donot contain more than 12 carbon atoms per molecule; and (D) a concentration of a dissolved component selected from the group consisting of polymer molecules which contain more than 12 atoms per molecule and in which at least 50 % of the polymer molecules is made up of one or more moieties with one of the general chemical formulas:
or where M represents a hydrogen atom, a monovalent cation, or a monovalent fraction of a polyvalent cation.
2. An aqueous liquid composition of matter according to claim 1, wherein: the concentration of component (A) has a ratio 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 moiety and at least one hydroxyl moiety that is not part of any carboxyl or carboxylate moiety; at least about 30 number % of the moieties "M" shown in the general chemical formulas in claim 1 for component (D) are hydrogen; component (D) has a weight average molecular weight from about 500 to about 9000; and the composition additionally comprises at least one of divalent manganese and divalent nickel cations in a total amount such that the concentration of zinc cations has a ratio to the total amount of divalent manganese and divalent nickel cations that is from about 1.0:3.5 to about 1.0:0.6.
3. An aqueous liquid composition of matter according to claim 2, wherein: the ratio of the concentration of component (A) to the concentration of component (B) is from about 1.0:18 to about 1.0:10; at least about 60 number % of said moieties "M" are hydrogen; at least about 60 % of component (D) consists of acrylate moieties;
component (D) has a weight average molecular weight from about 700 to about 1300;
the composition comprises both dissolved divalent manganese and divalent nickel cations in concentrations such that the concentration of manganese has a ratio to the concentration of nickel that is from about 1.0:1.5 to about 1.0:0.7; and the ratio of the concentration of zinc cations to the total amount of divalent manganese and divalent nickel cations is from about 1.0:3.5 to about 1.0:0.6.
component (D) has a weight average molecular weight from about 700 to about 1300;
the composition comprises both dissolved divalent manganese and divalent nickel cations in concentrations such that the concentration of manganese has a ratio to the concentration of nickel that is from about 1.0:1.5 to about 1.0:0.7; and the ratio of the concentration of zinc cations to the total amount of divalent manganese 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/kg; the concentration of component (D) is from about 5 to about 200 ppm; and the concentration of dissolved divalent manganese cations is from about 300 to about 3000 ppm.
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/kg; the concentration of component (D) is from about 10 to about 100 ppm; the concentration of dissolved divalent manganese cations is from about 500 to about 2000 ppm.
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/kg, at least about 70 % of component (D) consists of acrylate and methacrylate moieties, of which at least 50 number % have hydrogen as said moieties "M"; 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 ppm; the concentration of dissolved divalent manganese cations is from about 600 to about 1500 ppm; and the stoichiometric equivalent concentration of 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 component (A) to the concentration of 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 of these acids; the concentration of component (C) is from about 1.0 to about 7 mM/kg; at least about 75 % of component (D) consists of acrylate and methacrylate moieties, of which at least about 60 number %
have hydrogen as said moieties "M"; 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 ppm; the concentration of dissolved divalent manganese cations is from about 700 to about 1300 ppm; and the composition additionally comprises a dissolved source of hydroxylamine in an amount to provide a stoichiometric equivalent concentration of hydroxylamine that is from about 1.2 to about 2.3 ppt.
component (C) is selected from the group consisting of citric acid, gluconic acid, and heptogluconic acid and the water soluble salts of all of these acids; the concentration of component (C) is from about 1.0 to about 7 mM/kg; at least about 75 % of component (D) consists of acrylate and methacrylate moieties, of which at least about 60 number %
have hydrogen as said moieties "M"; 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 ppm; the concentration of dissolved divalent manganese cations is from about 700 to about 1300 ppm; and the composition additionally comprises a dissolved source of hydroxylamine in an amount to provide a stoichiometric equivalent concentration of hydroxylamine that 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 component (B) is from about 12.2 to about 17 ppt; the ratio of the concentration of component (A) to the concentration of 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/kg; 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 ppm; the concentration of dissolveddivalent manganese cations is from about 750 to about 1200 ppm; and the stoichiometric equivalent concentration of hydroxylamine is from about 1.3 to about 2.1 ppt.
9. An aqueous liquid composition according to claim 8, wherein: the concentration of component (A) is from about 0.85 to about 1.20 ppt; at least about 70 % of component (D) consists of acrylate moieties, of which at least 70 number % have hydrogen as said moieties "M"; the weight average molecular weight of component (D) is from about 900 to about 1700; the concentration of dissolved divalent manganeses cations is from about 800 to about 1000 ppm; and the composition also comprises dissolved nickel cations in a concentration from about 200 to about 1200 ppm.
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 component (A) to the concentration of 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 heptogluconic acid and the water soluble salts of all of these acids; the concentration of component (C) is from about 1.6 to about 4.1 mM/kg; at least about 80 % of component (D) consists of acrylate moieties, of which at least 80 number % have hydrogen as said moieties "M"; 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 ppm;
the concentration of dissolved divalent manganese cations is from about 800 to about 1000 ppm, the concentration of dissolved nickel cations is from about 600 to about 900 ppm; and the stoichiometric equivalent concentration of hydroxylamine is from about 1.5 to about 1.8 ppt.
the concentration of dissolved divalent manganese cations is from about 800 to about 1000 ppm, the concentration of dissolved nickel cations is from about 600 to about 900 ppm; and the stoichiometric equivalent concentration of 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 of iron, steel, zinc-iron alloy, galvanized steel and other predominantly zinciferous surfaces, and aluminum and its alloys that contain at least 45 % by weight of aluminum, said process comprising contacting the surface with a composition according to claim 10 at a temperature from about 35 to about 70 °C for a time not greater than 100 seconds, said composition according to claim 10 having a Free Acid content from about 1.0 to about 1.5 points, and a Total Acid content from about 20 to about 28 points; wherein, (i) if said surface includes a portion that contains at least 45 % of aluminum, said composition according to claim 10 additionally comprises fluorine containing constituents in an amount so as to result in a value from about 400 to about 600 ppm of free fluoride as measured by means of a fluoride sensitive electrode, and (ii) if said surface includes a portion that contains at least 85 %
of zinc but does not include any portion that contains at least 45 % of aluminum, said composition according to claim 10 additionally comprises a content of fluosilicate that is from about 1.10 to about 1.40 ppt, and said composition according to claim 10 has a free fluoride value that is not greater than about 20 ppm as measured by means of a fluoride sensitive electrode.
of zinc but does not include any portion that contains at least 45 % of aluminum, said composition according to claim 10 additionally comprises a content of fluosilicate that is from about 1.10 to about 1.40 ppt, and said composition according to claim 10 has a free fluoride value that is not greater than about 20 ppm as measured by means of a fluoride sensitive electrode.
12. 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 predominantly zinciferous surfaces, and aluminum and its alloys that contain at least 45 % by weight of aluminum, said process comprising contacting the surface with a composition according to claim 9 at a temperature from about 35 to about 70 °C for a time not greater than 100 seconds, said composition according to claim 9 having a Free Acid content from about 0.6 to about 1.5 points, and a Total Acid content from about 15 to about 40 points; wherein, (i) if said surface includes a portion that contains at least 45 % of aluminum, said composition according to claim 9 additionally comprises fluorine containing constituents in an amount so as to result in a value from about 250 to about 1200 ppm of free fluoride as measured by means of a fluoride sensitive electrode; and (ii) if said surface includes a portion that contains at least 85 %
of zinc but does not include any portion that contains at least 45 % of aluminum, said composition according to claim 9 additionally comprises a total content of fluoborate, fluosilicate, fluotitanate, and fluozirconate that is from about 0.5 to about 2.5 ppt, and said composition according to claim 9 has a free fluoride value that is not greater than about 100 ppm as measured by means of a fluoride sensitive electrode.
of zinc but does not include any portion that contains at least 45 % of aluminum, said composition according to claim 9 additionally comprises a total content of fluoborate, fluosilicate, fluotitanate, and fluozirconate that is from about 0.5 to about 2.5 ppt, and said composition according to claim 9 has a free fluoride value that is not greater than about 100 ppm as measured by means of a fluoride sensitive electrode.
13 . 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 predominantly zinciferous surfaces, and aluminum and its alloys that contain at least 45 % by weight of aluminum, said process comprising contacting the surface with a composition according to claim 8 at a temperature from about 35 to about 70 °C for a time not greater than 100 seconds, said composition according to claim 8 having a Free Acid content from about 0.6 to about 1.5 points, and a Total Acid content from about 15 to about 40 points, wherein, (i) if said surface includes a portion that contains at least 45 % of aluminum, said composition according to claim 8 additionally comprises fluorine containing constituents in an amount so as to result in a value from about 250 to about 1200 ppm of free fluoride as measured by means of a fluoride sensitive electrode; and (ii) if said surface includes a portion that contains at least 85 %
of zinc but does not include any portion that contains at least 45 % of aluminum, said composition according to claim 8 additionally comprises a total content of fluoborate, fluosilicate, fluotitanate, and fluozirconate that is from about 0.5 to about 2.5 ppt, and said composition according to claim 8 has a free fluoride value that is not greater than about 100 ppm as measured by means of a fluoride sensitive electrode.
of zinc but does not include any portion that contains at least 45 % of aluminum, said composition according to claim 8 additionally comprises a total content of fluoborate, fluosilicate, fluotitanate, and fluozirconate that is from about 0.5 to about 2.5 ppt, and said composition according to claim 8 has a free fluoride value that is not greater than about 100 ppm as measured by means of a fluoride sensitive electrode.
14. 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 predominantly zinciferous surfaces, and aluminum and its alloys that contain at least 45 % by weight of aluminum, said process comprising contacting the surface with a composition according to claim 7 at a temperature from about 35 to about 70 °C for a time not greater than 100 seconds, said composition according to claim 7 having a Free Acid content from about 0.2 to about 1.5 points, and a Total Acid content from about 15 to about 40 points; wherein, (i) if said surface includes a portion that contains at least 45 % of aluminum, said composition according to claim 7 additionally comprises fluorine containing constituents in an amount so as to result in a value from about 250 to about 1200 ppm of free fluoride as measured by means of a fluoride sensitive electrode; and (ii) if said surface includes a portion that contains at least 85 %
of zinc but does not include any portion that contains at least 45 % of aluminum, said composition according to claim 7 additionally comprises a total content of fluoborate, fluosilicate, fluotitanate, and fluozirconate that is from about 0.5 to about 2.5 ppt, and said composition according to claim 7 has a free fluoride value that is not greater than about 100 ppm as measured by means of a fluoride sensitive electrode.
of zinc but does not include any portion that contains at least 45 % of aluminum, said composition according to claim 7 additionally comprises a total content of fluoborate, fluosilicate, fluotitanate, and fluozirconate that is from about 0.5 to about 2.5 ppt, and said composition according to claim 7 has a free fluoride value that is not greater than about 100 ppm as measured by means of a fluoride sensitive electrode.
15. 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 predominantly zinciferous surfaces, and aluminum and its alloys that contain at least 45 % by weight of aluminum, said process comprising contacting the surface with a composition according to claim 6 at a temperature from about 35 to about 70 °C for a time not greater than 100 seconds, said composition according to claim 6 having a Free Acid content from about 0.2 to about 1.5 points, and a Total Acid content from about 15 to about 40 points; wherein, (i) if said surface includes a portion that contains at least 45 % of aluminum, said composition according to claim 6 additionally comprises fluorine containing constituents in an amount so as to result in a value from about 250 to about 1200 ppm of free fluoride as measured by means of a fluoride sensitive electrode; and (ii) if said surface includes a portion that contains at least 85 %
of zinc but does not include any portion that contains at least 45 % of aluminum, said composition according to claim 6 additionally comprises a total content of fluoborate, fluosilicate, fluotitanate, and fluozirconate that is from about 0.5 to about 2.5 ppt, and said composition according to claim 6 has a free fluoride value that is not greater than about 100 ppm as measured by means of a fluoride sensitive electrode.
of zinc but does not include any portion that contains at least 45 % of aluminum, said composition according to claim 6 additionally comprises a total content of fluoborate, fluosilicate, fluotitanate, and fluozirconate that is from about 0.5 to about 2.5 ppt, and said composition according to claim 6 has a free fluoride value that is not greater than about 100 ppm as measured by means of a fluoride sensitive electrode.
16. 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 predominantly zinciferous surfaces, and aluminum and its alloys that contain at least 45 % by weight of aluminum, said process comprising contacting the surface with a composition according to claim 5 at a temperature from about 35 to about 70 °C for a time not greater than 100 seconds, said composition according to claim 5 having a Free Acid content from about 0.2 to about 1.5 points, and a Total Acid content from about 15 to about 40 points; wherein, (i) if said surface includes a portion that contains at least 45 % of aluminum, said composition according to claim 5 additionally comprises fluorine containing constituents in an amount so as to result in a value from about 250 to about 1200 ppm of free fluoride as measured by means of a fluoride sensitive electrode; and (ii) if said surface includes a portion that contains at least 85 %
of zinc but does not include any portion that contains at least 45 % of aluminum, said composition according to claim 5 additionally comprises a total content of fluoborate, fluosilicate, fluotitanate, and fluozirconate that is from about 0.5 to about 2.5 ppt, and said composition according to claim 5 has a free fluoride value that is not greater than about 100 ppm as measured by means of a fluoride sensitive electrode.
of zinc but does not include any portion that contains at least 45 % of aluminum, said composition according to claim 5 additionally comprises a total content of fluoborate, fluosilicate, fluotitanate, and fluozirconate that is from about 0.5 to about 2.5 ppt, and said composition according to claim 5 has a free fluoride value that is not greater than about 100 ppm as measured by means of a fluoride sensitive electrode.
17. 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 predominantly zinciferous surfaces, and aluminum and its alloys that contain at least 45 % by weight of aluminum, said process comprising contacting the surface with a composition according to claim 4 at a temperature from about 35 to about 70 °C for a time not greater than 100 seconds, said composition according to claim 4 having a Free Acid content from about 0.2 to about 1.5 points, and a Total Acid content from about 15 to about 40 points; wherein, (i) if said surface includes a portion that contains at least 45 % of aluminum, said composition according to claim 4 additionally comprises fluorine containing constituents in an amount so as to result in a value from about 250 to about 1200 ppm of free fluoride as measured by means of a fluoride sensitive electrode; and (ii) if said surface includes a portion that contains at least 85 %
of zinc but does not include any portion that contains at least 45 % of aluminum, said composition according to claim 4 additionally comprises a total content of fluoborate, fluosilicate, fluotitanate, and fluozirconate that is from about 0.5 to about 2.5 ppt, and said composition according to claim 4 has a free fluoride value that is not greater than about 100 ppm as measured by means of a fluoride sensitive electrode.
of zinc but does not include any portion that contains at least 45 % of aluminum, said composition according to claim 4 additionally comprises a total content of fluoborate, fluosilicate, fluotitanate, and fluozirconate that is from about 0.5 to about 2.5 ppt, and said composition according to claim 4 has a free fluoride value that is not greater than about 100 ppm as measured by means of a fluoride sensitive electrode.
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 predominantly zinciferous surfaces, and aluminum and its alloys that contain at least 45 % by weight of aluminum, said process comprising contacting the surface with a composition according to claim 3, wherein, in said 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/kg; the concentration of component (D) is from about 5 to about 200 ppm; if said surface includes a portion that contains at least 45 % of aluminum, said composition additionally comprisesfluorine containing constituents in an amount so as to result in a value from about 250 to about 1200 ppm of free fluoride as measured by means of a fluoride sensitive electrode; if said surface includes a portion that contains at least 85 % of zinc but does not include any portion that contains at least 45 % of aluminum, said composition additionally comprises a total content of fluoborate, fluosilicate, fluotitanate, and fluozirconate that is from about 0.5 to about 2.5 ppt, and said composition has a free fluoride value that is not greater than about 100 ppm as measured by means of a fluoride sensitive electrode; and said composition has a Free Acid content from about 0.2 to about 1.5 points and a Total Acid content from about 15 to about 40 points.
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/kg; the concentration of component (D) is from about 5 to about 200 ppm; if said surface includes a portion that contains at least 45 % of aluminum, said composition additionally comprisesfluorine containing constituents in an amount so as to result in a value from about 250 to about 1200 ppm of free fluoride as measured by means of a fluoride sensitive electrode; if said surface includes a portion that contains at least 85 % of zinc but does not include any portion that contains at least 45 % of aluminum, said composition additionally comprises a total content of fluoborate, fluosilicate, fluotitanate, and fluozirconate that is from about 0.5 to about 2.5 ppt, and said composition has a free fluoride value that is not greater than about 100 ppm as measured by means of a fluoride sensitive electrode; and said composition has a Free Acid content from about 0.2 to about 1.5 points and a Total Acid content from about 15 to about 40 points.
19. 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 predominantly zinciferous surfaces, and aluminum and its alloys that contain at least 45 % by weight of aluminum, said process comprising contacting the surface with a composition according to claim 2, wherein, in said 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/kg; the concentration of component (D) is at least about 5 ppm; if said surface includes a portion that contains at least 45 %
of aluminum, said composition additionally comprises fluorine containing constituents in an amount so as to result in a value from about 250 to about 1200 ppm of freefluoride as measured by means of a fluoride sensitive electrode; if said surface includes a portion that contains at least 85 % of zinc but does not include any portion that contains at least 45 % of aluminum, said composition additionally comprises a total content of fluoborate, fluosilicate, fluotitanate, and fluozirconate that is from about 0.5 to about 2.5 ppt and said composition has a free fluoride value that is not greater than about 100 ppm as measured by means of a fluoride sensitive electrode; and said composition has a Free Acid content from about 0.2 to about 1.5 points and a Total Acid content from about 15 to about 40 points.
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/kg; the concentration of component (D) is at least about 5 ppm; if said surface includes a portion that contains at least 45 %
of aluminum, said composition additionally comprises fluorine containing constituents in an amount so as to result in a value from about 250 to about 1200 ppm of freefluoride as measured by means of a fluoride sensitive electrode; if said surface includes a portion that contains at least 85 % of zinc but does not include any portion that contains at least 45 % of aluminum, said composition additionally comprises a total content of fluoborate, fluosilicate, fluotitanate, and fluozirconate that is from about 0.5 to about 2.5 ppt and said composition has a free fluoride value that is not greater than about 100 ppm as measured by means of a fluoride sensitive electrode; and said composition has a Free Acid content from about 0.2 to about 1.5 points and a Total Acid content from about 15 to about 40 points.
20. A process for forming a phosphate conversion coating on a metal surface, said process comprising contacting the surface with a composition according to claim 1, wherein, in said 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/kg; the concentration of component (D) is from about 5 to about 200 ppm; and said composition has a Free Acid content from about 0.1 to about 3 points and a Total Acid content from about 15 to about 50 points.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US629495P | 1995-11-07 | 1995-11-07 | |
| US60/006,294 | 1995-11-07 | ||
| PCT/US1996/017086 WO1997017480A1 (en) | 1995-11-07 | 1996-10-31 | Finely crystalline and/or fast phosphate conversion coating composition and process |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2236173A1 true CA2236173A1 (en) | 1997-05-15 |
Family
ID=29405565
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2236173 Abandoned CA2236173A1 (en) | 1995-11-07 | 1996-10-31 | Finely crystalline and/or fast phosphate conversion coating composition and process |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2236173A1 (en) |
-
1996
- 1996-10-31 CA CA 2236173 patent/CA2236173A1/en not_active Abandoned
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