Composition and process for treating metal

Heating an aqueous mixture of a fluoroacid such as H.sub.2 TiF.sub.6 and an oxide, hydroxide, and/or carbonate such as silica produces a clear mixture with long term stability against settling of any solid phase, even when the oxide, hydroxide, or carbonate phase before heating was a dispersed solid with sufficiently large particles to scatter light and make the mixture before heating cloudy. The clear mixture produced by heating can be mixed with soluble hexavalent and/or trivalent chromium, and preferably also nitrate and chloride ions to produce a composition that provides a conversion coating with good protection against corrosion while requiring substantially less chromium than previous coatings of equal corrosion protective quality.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to processes of treating metal surfaces with aqueous 
acidic compositions to increase the resistance to corrosion of the treated 
metal surface, either as thus treated or after subsequent overcoating with 
some conventional organic based protective layer. A major object of the 
invention is to provide a storage stable, preferably single package, 
treatment that can be substantially free from hexavalent chromium but can 
protect metals substantially as well as the hexavalent chromium containing 
treatments of the prior art, or can improve the stability of treatment 
solutions that do contain hexavalent chromium and/or reduce the amount of 
chromium needed with such solutions to provide a specified degree of 
corrosion protection. This invention also relates to reaction of 
fluorometallic acids with other metal or metalloid containing materials to 
produce compositions or intermediates for compositions useful for such 
treatments. 
2. Statement of Related Art 
A very wide variety of materials have been taught in the prior art for the 
general purposes of the present invention, but most of them contain 
hexavalent chromium or other inorganic oxidizing agents which are 
environmentally undesirable. Also, many of the prior art treatment 
compositions include components that are chemically or physically unstable 
when mixed, so that single package concentrates for such treatment 
compositions are not practical. 
DESCRIPTION OF THE INVENTION 
GENERAL PRINCIPLES OF DESCRIPTION 
Except in the claims and the operating examples, or where otherwise 
expressly 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 in this description, unless expressly 
stated to the contrary: percent, "parts of", and ratio values are by 
weight; the term "polymer" includes "oligomer", "copolymer", "terpolymer", 
and the like; the description of a group or class of materials as suitable 
or preferred 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 preferred; description of constituents in chemical 
terms refers to the constituents at the time of addition to any 
combination specified in the description, and does not necessarily 
preclude chemical 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 constituents 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 
stated objects of the invention); and the term "mole" and its variations 
may be applied to elemental, ionic, and any other chemical species defined 
by number and type of atoms present, as well as to compounds with well 
defined molecules. 
OBJECTS OF THE INVENTION 
Various alternative or concurrent objects of the invention include: 
providing better corrosion resistance at no more than equal cost or equal 
corrosion resistance at lower cost to metal surfaces, particularly those 
of aluminum; reducing the amount of chromium and/or other polluting 
chemicals needed to provide a specified degree of corrosion protection; 
and improving the adherence of paint and like materials to metal surfaces 
treated according to the invention. Other objects will be apparent from 
the description below. 
SUMMARY OF THE INVENTION 
It has been found that aqueous compositions comprising (A) a component of 
dissolved fluoroacids of one or more metals and metalloid elements 
selected from the group of elements consisting of titanium, zirconium, 
hafnium, boron, aluminum, silicon, germanium, and tin and, (B) a component 
of one or more of (i) dissolved or dispersed finely divided forms of 
metals and metalloid elements selected from the group of elements 
consisting of titanium, zirconium, hafnium, boron, aluminum, silicon, 
germanium, and tin and (ii) the oxides, hydroxides, and carbonates of such 
metals and metalloid elements can be caused to chemically interact in such 
a manner as to produce a composition useful for novel metal treatments. If 
component (B) is present in dispersion rather than solution, as is 
generally preferred, the initial composition normally will not be 
optically transparent, because of the scattering of visible light, in a 
thickness of I centimeter ("cm"), and the occurrence of the desired 
chemical interaction can be determined by the clarification of the 
composition. If components (A) and (B) as defined above are both present 
in the precursor aqueous composition in sufficiently high concentrations, 
adequate chemical interaction between them may occur at normal ambient 
temperatures (i.e., 20.degree.-25.degree. C.) within a practical reaction 
time of 24 hours or less, particularly if component (B) is dissolved or 
dispersed in very finely divided form. Mechanical agitation may be useful 
in speeding the desired chemical interaction and if so is preferably used. 
Heating, even to relatively low temperatures such as 30.degree. C., is 
often useful in speeding the desired chemical interaction, and if it does 
so speed the reaction is usually preferred. The desired chemical 
interaction between components (A) and (B) of the mixed composition 
eliminates or at least markedly reduces any tendency toward settling of a 
dispersed phase that might otherwise occur upon long term storage of the 
initial mixture of components (A) and (B) as defined above. 
The compositions resulting from chemical interaction as described above may 
then be utilized as metal treating compositions, optionally after being 
combined with a component (C) that is either (i) a water soluble or 
dispersible polymer and/or copolymer, preferably selected from the group 
consisting of (i. 1) polymers and copolymers of one or more x-(N--R.sup.1 
--N--R.sup.2 -aminomethyl)-4-hydroxy-styrenes, where x=2, 4, 5, or 6, 
R.sup.1 represents an alkyl group containing from 1 to 4 carbon atoms, 
preferably a methyl group, and R.sup.2 represents a substituent group 
conforming to the general formula H(CHOH).sub.n CH.sub.2 --, where n is an 
integer from 1 to 7, preferably from 3 to 5, (i.2) epoxy resins, 
particularly polymers of the diglycidylether of bisphenol-A, optionally 
capped on the ends with non-polymerizable groups and/or having some of the 
epoxy groups hydrolyzed to hydroxyl groups, and (i.3) polymers and 
copolymers of acrylic and methacrylic acids and their salts; or (ii) a 
composition containing hexavalent chromium, and, optionally, trivalent 
chromium. 
Optionally, another component (D) made up of water soluble oxides, 
carbonates, or hydroxides of at least one of Ti, Zr, Hf, B, Al, Si, Ge, 
and Sn may also be added before, after, or simultaneously with component 
(C) but after the interaction of components (A) and (B). For this purpose, 
"water soluble" means a solubility to at least 1% in water at normal 
ambient temperature, and "water insoluble" means less soluble than this. 
The resulting compositions are suitable for treating metal surfaces to 
achieve excellent resistance to corrosion, particularly after subsequent 
conventional coating with an organic binder containing protective coating. 
The compositions are particularly useful on iron and steel, galvanized 
iron and steel, zinc and those of its alloys that contain at least 50 
atomic percent zinc, and, most preferably, aluminum and its alloys that 
contain at least 50 atomic percent aluminum. The treating may consist 
either of coating the metal with a liquid film of the composition and then 
drying this liquid film in place on the surface of the metal, or simply 
contacting the metal with the composition for a sufficient time to produce 
an improvement in the resistance of the surface to corrosion, and 
subsequently rinsing before drying. Such contact may be achieved by 
spraying, immersion, and the like as known per se in the art. When 
immersion is used, it is optional, and often advantageous, to contact the 
metal surface with an aqueous composition comprising polymers and 
copolymers of one or more x-(N--R.sup.1 --N--R.sup.2 
-aminomethyl)-4-hydroxy-styrenes, where x=2, 4, 5, or 6, R.sup.1 
represents an alkyl group containing from 1 to 4 carbon atoms, preferably 
a methyl group, and R.sup.2 represents a substituent group conforming to 
the general formula H(CHOH).sub.n CH.sub.2 --, where n is an integer from 
1 to 7, preferably from 3 to 5, after contacting the metal with a 
composition containing components (A) and (B) as described above, removing 
the metal from contact with this composition containing components ponents 
(A) and (B) as described above, and rinsing with water, but before drying. 
The invention also provides a process for effectively coating the 
above-stated metallic surfaces in the absence of an intermediate rinsing 
step. The process comprises the steps of (i) cleaning the metal surface to 
be coated, (ii) rinsing the cleaned metal surface with water so as to 
remove any excess cleaning solution, (iii) contacting the metallic surface 
with the above-described coating composition, and (iv) drying the coated 
metallic surface. 
There is also another embodiment of the present invention which provides a 
composition and process for coating surfaces of aluminum and alloys 
thereof, wherein the composition comprises, preferably consists 
essentially of, or more preferably consists of, water and a mixture of: 
(A') a water soluble or dispersible polymer having at least one alcohol 
functionality selected from the group consisting of polyvinyl alcohol, 
polyethylene glycol, modified starch, and mixtures thereof and (B') 
polymers and copolymers of acrylic and methacrylic acid and their salts, 
and, optionally, one or more of the following: a component (C') selected 
from the group consisting of the same fluorometallic acids, with the same 
preferences, as recited for component (A) herein; a component (D') of the 
same metallic and/or metalloid elements and their oxides, hydroxides, 
and/or carbonates, with the same preferences, as recited for component (B) 
herein; and a component (E') selected from the group consisting of the 
same water soluble oxides, carbonates, or hydroxides of at least one of 
Ti, Zr, Hf, B, Al, Si, Ge, and Sn, with the same preferences, as recited 
for component (D) herein. 
It should be understood, as already pointed out above, that the 
descriptions of compositions above do not preclude the possibility of 
unspecified chemical interactions among the components listed, but instead 
describes the components of a composition according to the invention in 
the form in which they are generally used as ingredients to prepare such a 
composition. In fact, a chemical interaction, most probably to produce 
oxyfluro complexes of the metal or metalloid elements or their compounds 
heated in contact with fluorometallic acids, is believed to occur, but the 
invention is not limited by any such theory. 
DESCRIPTION OF PREFERRED EMBODIMENTS 
To the extent that their water solubility is sufficient, the fluoroacid 
component (A) to be caused to interact in a mixture with water and one or 
more metals and/or metalloid elements and/or oxides, hydroxides, and/or 
carbonates thereof in a process according to one embodiment of the 
invention may be freely selected from the group consisting of H.sub.2 
TiF.sub.6, H.sub.2 ZrF.sub.6, H.sub.2 HfF.sub.6, H.sub.3 AlF.sub.6, 
H.sub.2 SiF.sub.6, H.sub.2 GeF.sub.6, H.sub.2 SnF.sub.6, HBF.sub.4, and 
mixtures thereof. H.sub.2 TiF.sub.6, H.sub.2 ZrF.sub.6, H.sub.2 HfF.sub.6, 
H.sub.2 SiF.sub.6, HBF.sub.4, and mixtures thereof are preferred; H.sub.2 
TiF.sub.6, H.sub.2 ZrF.sub.6, H.sub.2 SiF.sub.6 and mixtures thereof are 
more preferred; and H.sub.2 TiF.sub.6 is most preferred. The concentration 
of fluoroacid component at the time of interaction preferably is at least, 
with increasing preference in the order given, 0.01, 0.02, 0.04, 0.08, 
0.12, 0.16, 0.20, 0.24, 0.27, 0.29, 0.31, 0.33, 0.35, 0.360, 0.365, 0.370, 
0.375, 0.380, or 0.385 moles per kilogram (hereinafter usually abbreviated 
as "M/kg") of the total mixture in which the interaction with component 
(B) occurs and independently preferably is not more than, with increasing 
preference in the order given, 7, 5, 3, 2.0, 1.5, 1.0, 0.80, 0.65, 0.60, 
0.55, 0.50, 0.45, 0.42, or 0.40 M/kg of the total mixture in which the 
interaction with component (B) occurs. 
Component (B) of metallic and/or metalloid elements and/or their oxides, 
hydroxides, and/or carbonates is preferably selected from the group 
consisting of the oxides, hydroxides, and/or carbonates of silicon, 
zirconium, and/or aluminum, more preferably includes silica, and still 
more preferably includes both zirconium and silicon in a molar ratio of 
silicon to zirconium that is at least, with increasing preference in the 
order given, 0.5:1.0, 0.7:1.0, 0.9:1.0, 1.1:1.0, 1.20:1.0, 1.30:1.0, 
1.40:1.0, 1.45:1.0, 1.50:1.0, 1.55:1.0, 1.60:1.0, 1.65:1.0, 1.70:1.0, 
1.75:1.0, 1.79:1.0, or 1.83:1.0 and independently preferably is not more 
than, with increasing preference in the order given, 7:1.0, 5:1.0, 
4.0:1.0, 3.5:1.0, 3.0:1.0, 2.7:1.0, 2.5:1.0, 2.3:1.0, 2.1:1.0, or 1.9:1.0. 
Any form of component (B) that is sufficiently finely divided to be readily 
dispersed in water may be used in a process according to one embodiment of 
this invention, but for constituents of this component that have low 
solubility in water it is preferred that the constituent be amorphous 
rather than crystalline, because crystalline constituents can require a 
much longer period of heating and/or a higher temperature of heating to 
produce a composition that is no longer susceptible to settling and 
optically transparent. Solutions and/or sols such as silicic acid sols may 
be used, but, if the composition according to the invention that is made 
with them is intended for use by drying a layer of it into place on a 
surface to be treated, it is highly preferable, as described further 
below, that the solutions and/or sols be substantially free from alkali 
metal ions. However, it is generally most preferred to use dispersions of 
very finely divided silica made by pyrogenic processes. 
The ratio of total moles of fluoroacid component (A) to total moles of 
component (B) in an aqueous composition heated according to one embodiment 
of this invention preferably is from 1:1 to 50:1, more preferably from 
1.5:1.0 to 20:1, or still more preferably from 1.5:1 to 5.0:1.0, except 
that if component (B) includes both silicon and zirconium and the 
composition made is ultimately intended to contain hexavalent chromium, 
the ratio of total moles of fluoroacid component (A) to total moles of 
component (B) instead preferably is at least, with increasing preference 
in the order given, 0.05:1.0, 0.10:1.0, 0.20:1.0, 0.30:1.0, 0.40:1.0, 
0.50:1.0, 0.55:1.0, 0.60:1.0, 0.65:1.0, 0.70:1.0, 0.75:1.0, 0.80:1.0, or 
0.85:1.0 and independently preferably is not more than, with increasing 
preference in the order given, 5.0:1.0, 4.0:1.0, 3.0:1.0, 2.5:1.0, 
2.0:1.0, 1.5:1.0, 1.2:1.0, 1.0:1.0, or 0.90:1.0. 
According to one embodiment of the invention, an aqueous liquid composition 
comprising, preferably consisting essentially of, or more preferably 
consisting of, water and components (A) and (B) as described above, which 
composition (i) scatters visible light, (ii) is not optically transparent 
in a thickness of 1 cm, and/or (iii) undergoes an extent of settling of a 
solid phase that is detectable with unaided human vision if maintained for 
at least 100 hours at a temperature between its freezing point and 
20.degree. C., is maintained at a temperature of at least 21.degree. C., 
optionally with mechanical agitation, for a sufficient time to produce a 
composition that (i) does not suffer any visually detectable settling when 
stored for a period of 100, or more preferably 1000, hours and (ii) is 
optically transparent in a thickness of 1 cm. Preferably, the temperature 
at which the initial mixture of components (A) and (B) is maintained is in 
the range from 25.degree. to 100.degree. C., or more preferably within the 
range from 30.degree. to 80.degree. C., and the time that the composition 
is maintained within the stated temperature range is within the range from 
3 to 480, more preferably from 5 to 90, or still more preferably from 10 
to 30, minutes (hereinafter often abbreviated "min"). Shorter times and 
lower temperatures within these ranges are generally adequate for 
converting compositions in which the component (B) is selected only from 
dissolved species and/or dispersed amorphous species without any surface 
treatment to reduce their hydrophilicity, while longer times and/or higher 
temperatures within these ranges are likely to be needed if component (B) 
includes dispersed solid crystalline materials and/or solids with surfaces 
treated to reduce their hydrophilicity. With suitable equipment for 
pressurizing the reaction mixture, even higher temperatures than 
100.degree. C. can be used in especially difficult cases. 
Independently, it is preferred that the pH of the aqueous liquid 
composition combining components (A) and (B) as described above be kept in 
the range from 0 to 4, more preferably in the range from 0.0 to 2.0, or 
still more preferably in the range from 0.0 to 1.0 before beginning 
maintenance at a temperature of at least 21.degree. C. as described above. 
A composition made as described immediately above is suitable for use as a 
protective treatment for metals. In many cases, however, a better 
protective treatment composition may be obtained by mixing the product of 
interaction between components (A) and (B) as described above with a third 
component (C) as also noted above. To make such compositions including 
component (C), after maintenance of a composition containing components 
(A) and (B) as described above at a temperature and for a time sufficient 
to promote their interaction, the composition is preferably brought if 
necessary to a temperature below 30.degree. C. and then mixed with a 
component consisting of at least one of (i) at least one water soluble or 
dispersible polymer and/or copolymer, preferably selected from the group 
consisting of (i.1) polyhydroxyl alkylamino derivatives of 
poly{p-hydroxystyrene} as described above and, in more detail, in U.S. 
Pat. No. 4,963,596, the entire disclosure of which, except to the extent 
contrary to any explicit statement herein, is hereby incorporated herein 
by reference, (i.2) epoxy resins, particularly polymers of the 
diglycidylether of bisphenol-A, optionally capped on the ends with 
non-polymerizable groups and/or having some of the epoxy groups hydrolyzed 
to hydroxyl groups, and (i.3) polymers and copolymers of acrylic and 
methacrylic acids and their salts; and (ii) a composition containing 
hexavalent chromium, and, optionally, trivalent chromium, as known per se 
in the art for treating metals, particularly aluminum and its alloys, to 
retard corrosion thereon. Suitable and preferred water soluble polymers 
and methods of preparing them are described in detail in U.S. Pat. No. 
4,963,596. Preferably, the ratio by weight of the solids content of 
component (C) to the total of active ingredients of component (A) as 
described above is in the range from 0.1 to 3, more preferably from 0.2 to 
2, or still more preferably from 0.20 to 1.6, except that when component 
(C) is predominantly constituted of compounds of hexavalent chromium, the 
molar ratio of chromium atoms in component (C) to the total of metal and 
metalloid atoms in components (A) and (B) preferably is at least, with 
increasing preference in the order given, 0.3:1.0, 0.5:1.0, 0.7:1.0, 
0.80:1.0, 0.90:1.0, 0.95:1.0, 1.00:1.0, 1.05:1.0, or 1.10:1.0 and 
independently preferably is not more than, with increasing preference in 
the order given, 10:1.0, 8:1.0, 6:1.0, 4.0:1.0, 3.0:1.0, 2.7:1.0, 2.4:1.0, 
2.1:1.0, 1.9:1.0, 1.7:1.0, 1.5:1.0, 1.40:1.0, 1.35:1.0, 1.30:1.0, 
1.25:1.0, 1.20:1.0, or 1.15:1.0. 
The preferred concentration of components (A) and (B) in a working 
composition according to the invention that includes hexavalent chromium 
compounds as a predominant part of component (C) is considerably less than 
the concentrations specified above as preferred for the initial 
interaction between components (A) and (B). Specifically, in a working 
composition according to the invention, suitable for direct contact with a 
metal substrate to form a corrosion resistant coating thereon, the total 
concentration of titanium, zirconium, hafnium, boron, aluminum, silicon, 
germanium, and tin atoms from component (A) preferably is at least, with 
increasing preference in the order given, 1.0, 2.0, 4.0, 6.0, 8.0, 10, 12, 
14, 16, 18, or 19 millimoles per liter (hereinafter usually abbreviated as 
"mM/L") and independently preferably is not more than, with increasing 
preference in the order given, 200, 150, 100, 80, 60, 50, 40, 35, 30, 25, 
or 21 mM/L. Concentrations of other constituents of working compositions 
preferably are such as to result in ratios to the concentration of 
component (A) and to one another as already specified above. 
A composition prepared by a process as described above constitutes another 
embodiment of this invention. It is normally preferred that compositions 
according to the invention as defined above should be substantially free 
from many ingredients used in compositions for similar purposes in the 
prior art. Specifically, it is often increasingly preferred in the order 
given, independently for each preferably minimized component listed below, 
that these compositions, when directly contacted with metal in a process 
according to this invention, contain no more than 1.0, 0.35, 0.10, 0.08, 
0.04, 0.02, 0.01, or 0.001% of each of the following constituents: 
hexavalent chromium; ferricyanide; ferrocyanide; anions containing 
molybdenum or tungsten; nitrates and other oxidizing agents (the others 
being measured as their oxidizing stoichiometric equivalent as nitrate); 
phosphorus and sulfur containing anions that are not oxidizing agents; 
alkali metal and ammonium cations; and organic compounds with two or more 
hydroxyl groups per molecule and a molecular weight of less than 300, 
except that: 
(i) the preference for minimal amounts of alkali metal and ammonium cations 
applies only to compositions used for processes according to the invention 
that include drying into place on the metal surface to be treated without 
rinsing after contact between the metal surface and the composition 
containing at least components (A) and (B) as described above; when a 
composition according to the invention is contacted with a metal surface 
and the metal surface is subsequently rinsed with water before being 
dried, any alkali metal and ammonium ions present are usually removed by 
the rinsing to a sufficient degree to avoid any substantial diminution of 
the protective value of subsequently applied organic binder containing 
protective coatings; 
(ii) the preference for minimization of the amount of hexavalent chromium 
present is due to the polluting effect of hexavalent chromium, and where 
there is an absence of legal restraints against pollution and/or 
sufficiently economical means of disposing of the hexavalent chromium 
without environmental damage exist, this preference does not apply; in 
fact, in one specialized embodiment of the invention, as already noted 
above, hexavalent chromium may advantageously be incorporated into working 
compositions according to this invention themselves, and in another 
specialized embodiment of the invention, liquid compositions containing 
hexavalent chromium may be used as posttreatments after application of a 
coating according to this invention but before final overcoating with a 
paint or the like, in order further to improve corrosion resistance of the 
metal surface treated; and 
(iii) if substantial amounts of hexavalent chromium are present in 
compositions according to the invention, the preference against nitrates 
and other oxidizing agents does not apply; in fact, in such compositions 
it is normally preferred, in order to obtain coatings with sufficient 
corrosion protective value in shorter times and/or at lower temperatures, 
for a working composition according to the invention to contain another 
oxidizing component, often designated for convenience hereinafter as 
optional component (E), that comprises, preferably consists essentially 
of, or more preferably consists of oxidizing agents other than compounds 
containing hexavalent chromium. 
Independently, when it is present, component (E) preferably comprises both 
(E. 1) nitrate ions and (E.2) halide ions. In a working composition 
according to the invention, the concentration of nitrate ions when present 
independently preferably is at least, with increasing preference in the 
order given, 1, 2, 4, 6, 8, 10, 12, 14, or 16 mM/L and independently 
preferably is is not more than, with increasing preference in the order 
given, 100, 75, 50, 40, 30, 26, 23, 21, 19, or 18 mM/L. Also, the 
concentration of halide ions when present independently preferably is at 
least, with increasing preference in the order given, 0.01, 0.02, 0.04, 
0.08, 0.15, 0.20, 0.30, 0.35, 0.40, 0.45, or 0.50 mM/L and independently 
preferably is not more than, with increasing preference in the order 
given, 50, 30, 20, 10, 5, 4.0, 3.0, 2.0, 1.0, 0.80, 0.70, 0.65, 0.60, or 
0.55 mM/L. Any fluoride ions that might be present in the composition as a 
result of dissociation of part of component (A) are not to be considered 
as halide ions for the purpose of measuring these preferred 
concentrations; instead, only separately added salts or acids containing 
and/or dissociating to uncomplexed halide ions are to be considered. Both 
nitrate ions and halide ions are preferably supplied to the composition by 
addition of water soluble salts containing these ions; primarily for 
reasons of economy, these salts are preferably alkali metal salts, most 
preferably sodium salts. Independently, the halide ions for optional 
component (E.2), primarily for reasons of economy, are preferably chloride 
ions. 
The other major type of coating used in the invention, employing a coating 
composition including necessary components (A') and (B') as already 
described above, has been found to be especially useful for treating 
metallic surfaces that are exposed to alkali metal ions, particularly 
sodium such as often occurs in detergents and other cleaners, after the 
treatment with a composition according to this invention has been 
completed. (Protective coatings applied to metallic surfaces, particularly 
aluminum, preferably are water insoluble and inhibit corrosion. However, 
metallic surfaces bearing a protective coating are often exposed to sodium 
ions later. It is believed that, upon exposure of some prior art coatings 
to sodium ions, the sodium ions oftentimes at least partially replace the 
aluminum in the formed coating, much as in an ion-exchange resin; such 
replacement in turn causes the film coating to be water sensitive, by 
increasing its solubility in water.) In an effort to decrease adverse 
effects of alkali metal ions on the treated surfaces, it has been found 
that by combining (i) polymers and copolymers of acrylic and methacrylic 
acids and their salts having an average molecular weight of about 50,000 
with (ii) a water soluble or dispersible polymer having at least one --OH 
group per polymer molecule, adverse effects from exposure of the treated 
surface to alkali metal ions can be reduced. Possibly this occurs because 
the alcohol functionality cross-links by esterfication with the acid 
functions. In a particularly preferred embodiment of this embodiment of 
the invention, the composition contacted with a metallic surface 
comprises, preferably consists essentially of, or more preferably consists 
of water and: (A') from 0.5 to 50 g/l and (B') from 0.5 to 50, and more 
preferably from 0.5 to 16 g/l of polyvinyl alcohol. The polyvinyl alcohol 
used in the invention preferably is a low molecular weight polyvinyl 
alcohol which is 75-99+mole % hydrolyzed, and has an average degree of 
polymerization ranging from 100-600. 
While any water soluble or dispersible polymer having at least one --OH 
group per polymer molecule may be employed without departing from the 
spirit of this embodiment of the invention, preferred polymers and amounts 
thereof include the above-stated polyvinyl alcohol; from 0.3 to 16 g/l, 
preferably from 0.3 to 1.2 g/l, of polyethylene glycol having a molecular 
weight of from 90,000 to 900,000; and from 0.5 to 16 g/l, preferably from 
0.5 to 10 g/l of dextrin, cyclodextrin, or a modified starch. 
The term "modified starch" is one commonly known in the art. It refers to 
any of several water-soluble polymers derived from a starch by 
acetylation, chlorination, acid hydrolysis, or enzymatic action. These 
reactions yield starch acetates, esters, and ethers in the form of stable 
and fluid solutions and films. These starch derivatives useful herein are 
well known. 
The hydroxyalkyl starch ethers and starch esters can be obtained by known 
etherification and esterification processes. These starch ethers and 
esters should have a degree of substitution (hereinafter often abbreviated 
"D.S.") of 0.01 to 0.5, and preferably 0.1 to 0. 5. As used herein D.S. 
means the average degree of substitution, per anhydroglucose unit of the 
corresponding unmodified starch, of hydroxyl groups in the starch by 
chemical modifying substituents, such as, for example, hydroxalkyl and/or 
carbonyl groups. 
Oxidized starch can be obtained by known processes involving oxidation of 
starch with a suitable oxidizing agent, as for example sodium 
hypochlorite, potassium dichromate and sodium permanganate. The starch can 
be oxidized under acidic, alkaline or neutral conditions, and the 
resulting product can contain carboxyl and carbonyl groups. Preferably the 
oxidized starch has a "D.O." value of 0.01 to 1.0, where "D.O." refers to 
the number of carboxyl groups introduced per anhydroglucose unit of the 
corresponding unmodified starch. These starch derivatives and methods for 
obtaining them are discussed in Whistler and Paschall (eds.), Starch: 
Chemistry and Technology, vol. I, (Academic Press, New York,1965), pp. 
458-78. 
Dextrins and cyclodextrins are polysaccharide products of a complex nature 
resulting from the partial degradation of starch, such as corn starch, 
potato starch, wheat starch, and the like, with heat, as for example, by 
roasting with acid or alkaline catalysts. Linear and branched dextrins are 
classified in three types. The particular type obtained depends on the 
heating time, temperature, and catalyst employed in the treatment of the 
starch. These types are classified as white dextrins, yellow or canary 
dextrins, and British gums, and all such dextrins are suitable herein. 
White and canary dextrins are preferred because British gums are brown in 
color. White dextrins are preferably pregelatinized (made water soluble 
during manufacture), if necessary, to render them more readily mixed with 
other water soluble components. Dextrins and methods for obtaining them 
are well known. See, for example, Whistler and Paschall, op. cit., vol. I, 
p. 421 ff and vol. II, p. 253 ff 
The starch hydrolysates useful in the compositions of this invention are a 
relatively new class of starch materials. These starch hydrolysates are 
made by subjecting a source of starch, such as hereinbefore mentioned, to 
enzyme or acid treatment or a combination of both. It is important that 
the starch hydrolysate have a relatively low dextrose equivalent 
(hereinafter often abbreviated "D.E."). The starch hydrolysate should have 
a D.E. of from 2 to 35, and preferably have a D.E. of from 5 to 25. The 
most preferred materials have a D.E. within the range of 5 to 15. (The 
term D.E. is used herein to refer to the reducing sugars content of the 
dissolved solids in a starch hydrolysate expressed as percent dextrose as 
measured by the Luff-Schoorl method NBS Circular C-40, p. 195; also 
appearing in Polarimetry, Saccharimet, and the Sugars published by 
Frederick J. Bates and Associates!.) 
Particularly preferred modified starches include cyclodextrins, which are 
macro-cyclic non-reducing D-glucosyl polymers containing six or more 
D-glucosyl residues bonded by .alpha.-(1,4) links. A more detailed 
description of cyclodextrins can be found in Whistler and Paschall, op. 
cit., Vol. 1, pp. 209-224. 
The pH of a composition according to this invention that contains 
components (A') and (B') as necessary components preferably is in the 
range from 1.0 to 5.0, and more preferably from 1.0 to 3.5. 
In a preferred embodiment of the aspect of the invention utilizing 
necessary components (A') and (B'), the treating composition also includes 
from 0.2 to 19.0, and more preferably from 0.2 to 8.0 g/l, of fluoroacids 
component (C') admixed therein. Component (C') is preferably selected from 
the group consisting of H.sub.2 TiF.sub.6, H.sub.2 ZrF.sub.6, and H.sub.2 
SiF.sub.6, and more preferably is H.sub.2 TiF.sub.6 or H.sub.2 ZrF.sub.6. 
Still another embodiment of the invention is a process of treating a metal 
with a composition prepared as described above. In one embodiment of the 
invention, it is preferred that the aqueous composition as described above 
be applied to the metal surface and dried in place thereon. For example, 
coating the metal with a liquid film may be accomplished by immersing the 
surface in a container of the liquid composition, spraying the composition 
on the surface, coating the surface by passing it between upper and lower 
rollers with the lower roller immersed in a container of the liquid 
composition, and the like, or by a mixture of methods. Excessive amounts 
of the liquid composition that might otherwise remain on the surface prior 
to drying may be removed before drying by any convenient method, such as 
drainage under the influence of gravity, squeegees, passing between rolls 
spaced a short specified distance apart, and the like. 
If the surface to be coated is a continuous flat sheet or coil and 
precisely controllable coating techniques such as gravure roll coaters are 
used, a relatively small volume per unit area of a concentrated 
composition may effectively be used for direct application. On the other 
hand, if the coating equipment used does not readily permit precise 
coating at low coating add-on liquid volume levels, it is equally 
effective to use a more dilute acidic aqueous composition to apply a 
thicker liquid coating that contains the same amount of active 
ingredients. In either case, when compositions according to the invention 
containing necessary ingredients (A) and (B) as described above are used, 
it is preferred that the total amount of active ingredients of components 
(A), (B), and (C) as described above that are dried into place on the 
surface to be treated, or that remain as add-on mass on the surface after 
exposure to a working composition according to the invention and 
subsequent rinsing and, optionally, drying, is at least, with increasing 
preference in the order given, 1, 2, 4, 8, 15, 30, 50, 70, 80, 90, 100, 
110, 120, or 125 milligrams per square meter (hereinafter often 
abbreviated as "mg/m.sup.2 ") of surface area treated and independently, 
primarily for reasons of economy, preferably is not more than 500, 400, 
300, 250, 200, 180, 170, 150, or 140 mg/m.sup.2. 
Drying may be accomplished by any convenient method, of which many are 
known per se in the art; examples are hot air and infrared radiative 
drying. Independently, it is preferred that the maximum temperature of the 
metal reached during drying fall within the range from 30 to 200, more 
preferably from 30 to 150, still more preferably from 30 to 75, .degree.C. 
Also independently, it is often preferred that the drying be completed 
within a time ranging from 0.5 to 300, more preferably from 2 to 50, still 
more preferably from 2 to 10, seconds (hereinafter abbreviated "sec") 
after coating is completed. 
According to an alternative embodiment of the invention, the metal to be 
treated preferably is contacted with a composition prepared as described 
above at a temperature that is at least, with increasing preference in the 
order given, 15.degree., 18.degree., 21.degree., 24.degree., or 26.degree. 
C. and independently, primarily for reasons of economy, preferably is not 
more than, with increasing preference in the order given, 90.degree., 
85.degree., 80.degree., 70.degree., 65.degree., or 60.degree. C. and if 
the composition contains hexavalent chromium compounds as the predominant 
part of component (C), still more preferably is not more than, with 
increasing preference in the order given, 55.degree., 50.degree., 
45.degree., 40.degree., 35.degree., 32.degree., or 29.degree. C. 
Independently, the metal to be treated preferably remains in contact with 
a working composition according to the invention for a time that is at 
least, with increasing preference in the order given, 1, 3, 5, 7, 9, 20, 
or 30 sec and, if the working composition according to the invention 
contains a component (C) that is constituted predominantly of compounds 
containing hexavalent chromium more preferably is at least, with 
increasing preference in the order given, 50, 75, 100, 125, 150, or 175 
sec and independently, primarily for reasons of economy, preferably is not 
more than, with increasing preference in the order given, 1800, 1200, 600, 
or 300 sec and unless the working composition according to the invention 
contains a component (C) that is constituted predominantly of compounds 
containing hexavalent chromium more preferably is not more than, with 
increasing preference in the order given, 200, 100, 75, 50, or 30 sec, and 
the metal surface thus treated is subsequently rinsed with water in one or 
more stages before being dried. In this embodiment, at least one rinse, 
preferably the last rinse, after treatment with a composition according 
this invention preferably is with deionized, distilled, or otherwise 
purified water. Also in this embodiment, it is preferred that the maximum 
temperature of the metal reached during drying fall within the range from 
30 to 200, more preferably from 30to 150, or still more preferably from 30 
to 75, .degree.C. and that, independently, drying be completed within a 
time ranging from to 0.5 to 300, more preferably from 2 to 50, still more 
preferably from 2 to 10, sec after the last contact of the treated metal 
with a liquid before drying is completed. 
A process according to the invention as generally described in its 
essential features above may be, and usually preferably is, continued by 
coating the dried metal surface produced by the treatment as described 
above with a siccative coating or other protective coating, relatively 
thick as compared with the coating formed by the earlier stages of a 
process according to the invention as described above. Such protective 
coatings may generally, in connection with this invention, be selected and 
applied as known per se in the art. Surfaces thus coated have been found 
to have excellent resistance to subsequent corrosion, as illustrated in 
the examples below. Particularly preferred types of protective coatings 
for use in conjunction with this invention include acrylic and polyester 
based paints, enamels, lacquers, and the like. However, in the specialized 
embodiment of the invention described above wherein the working 
composition according to the invention contains a component (C) that is 
constituted predominantly of compounds containing hexavalent chromium, 
excellent corrosion resistance, particularly on aluminum, can be achieved 
even without subsequently covering a surface treated with a composition 
according to the invention with any such additional protective coating. 
In a process according to the invention that includes other steps after the 
formation of a protective layer on the surface of a metal by contacting 
the metal with a composition according to the invention as described above 
and that operates in an environment in which the discharge of hexavalent 
chromium is either legally restricted or economically handicapped, it is 
generally preferred that none of these other steps include contacting the 
surfaces with any composition that contains more than, with increasing 
preference in the order given, 1.0, 0.35, 0.10, 0.08, 0.04, 0.02, 0.01, 
0.003, 0.001, or 0.0002% of hexavalent chromium. Examples of suitable and 
preferred chromium free treatments are described in U.S. Pat. No. 
4,963,596. However, in certain specialized instances, hexavalent chromium 
may impart sufficient additional corrosion protection to the treated metal 
surfaces to justify the increased cost of using and lawfully disposing of 
it. 
Preferably, the metal surface to be treated according to the invention is 
first cleaned of any contaminants, particularly organic contaminants and 
foreign metal fines and/or inclusions. Such cleaning may be accomplished 
by methods known to those skilled in the art and adapted to the particular 
type of metal substrate to be treated. For example, for galvanized steel 
surfaces, the substrate is most preferably cleaned with a conventional hot 
alkaline cleaner, then rinsed with hot water, squeegeed, and dried. For 
aluminum, the surface to be treated most preferably is first contacted 
with either an aqueous alkaline cleaning solution in accordance with that 
disclosed in U.S. Pat. No. 4,762,638, incorporated herein by reference, or 
an aqueous acidic cleaning solution as disclosed in U.S. Pat. No. 
4,370,173, also incorporated herein by reference. With respect to the 
aqueous acidic cleaning solution, it should also be noted that a source of 
fluoride such as HF may also be employed to even further enhance the 
cleaning process. Irrespective of the type of cleaning solution employed, 
the aluminum is then subjected to a water rinse and optionally but 
preferably to a deoxidizing process as known in the art and another rinse 
after the deoxidizing process, after which a composition in accordance 
with the present invention may then be coated onto the aluminum in 
accordance with one of the processes disclosed herein. 
The practice of this invention may be further appreciated by consideration 
of the following, non-limiting, working examples, and the benefits of the 
invention may be further appreciated by reference to the comparison 
examples. 
GROUP I 
WORKING COMPOSITIONS AND PROCESSES USING NECESSARY COMPONENTS (A) AND (B), 
WITH DRY IN PLACE TREATMENTS 
Test Methods and Other General Conditions 
Test pieces of Type 3105 aluminum were spray cleaned for 15 seconds at 
54.4.degree. C. with an aqueous cleaner containing 28 g/L of CO.RTM. 
Cleaner 305 (commercially available from the Parker+Amchem Division of 
Henkel Corp., Madison Heights, Mich., USA). After cleaning, the panels 
were rinsed with hot water, squeegeed, and dried before roll coating with 
an acidic aqueous composition as described for the individual examples and 
comparison examples below. 
For this first group of examples and comparison examples, the applied 
liquid composition according to the invention was flash dried in an 
infrared oven that produces approximately 49.degree. C. peak metal 
temperature. Samples thus treated were subsequently coated, according to 
the recommendations of the suppliers, with various commercial paints as 
specified further below. 
T-Bend tests were according to American Society for Testing materials 
(hereinafter "ASTM") Method D4145-83; Impact tests were according to ASTM 
Method D2794-84E1; Salt Spray tests were according to ASTM Method B-117-90 
Standard; Acetic Acid Salt Spray tests were according to ASTM Method 
B-287-74 Standard; and Humidity tests were according to ASTM D2247-8 
Standard. The Boiling water immersion test was performed as follows: A 2T 
bend and a reverse impact deformation were performed on the treated and 
painted panel. The panel was then immersed for 10 minutes in boiling water 
at normal atmospheric pressure, and areas of the panel most affected by 
the T-bend and reverse impact deformations were examined to determine the 
percent of the paint film originally on these areas that had not been 
exfoliated. The rating is reported as a number that is one tenth of the 
percentage of paint not exfoliated. Thus, the best possible rating is 10, 
indicating no exfoliation; a rating of 5 indicates 50% exfoliation; etc. 
Specific Compositions

EXAMPLE 1 
5.6 parts of amorphous fumed silicon dioxide 
396.2 parts of deionized water 
56.6 parts of aqueous 60% fluotitanic acid (i.e., H.sub.2 TiF.sub.6) 
325.4 parts of deionized water 
216.2 parts of an aqueous solution containing a mixture of 4.1 g/l 
polyacrylic acid and 4.0 g/l polyvinyl alcohol 
EXAMPLE 2 
58.8 parts of aqueous 60% fluotitanic acid 
646.0 parts of deionized water 
5.9 parts of amorphous fumed silicon dioxide 
10.5 parts of zirconium hydroxide 
278.8 parts of the 10% solution of water soluble polymer as used in Example 
1. 
EXAMPLE 3 
62.9 parts of aqueous 60% fluotitanic acid 
330.5 parts of deionized water 
6.2 parts of amorphous fumed silicon dioxide 
358.9 parts of deionized water 
241.5 parts of the 10% water soluble polymer solution as used in Example 1 
EXAMPLE 4 
56.4 parts of aqueous 60% fluotitanic acid 
56.4 parts of deionized water 
2.1 parts of Aerosil.TM. R-972 (a surface treated dispersed silica) 
667.0 parts of deionized water 
218.1 parts of the 10% water soluble polymer solution as used in Example 1 
EXAMPLE 5 
58.8 parts of aqueous 60% fluotitanic acid 
3.7 parts of amorphous fumed silicon dioxide 
10.3 parts of zirconium basic carbonate 
647.7 parts of deionized water 
279.5 parts of the 10% solution of water soluble polymer as used in Example 
1 
EXAMPLE 6 
52.0 parts of aqueous 60% fluotitanic acid 
297.2 parts of deionized water 
3.3 parts of amorphous fumed silicon dioxide 
9.1 parts of zirconium basic carbonate 
273.6 parts of deionized water 
364.8 parts of the 10% solution of water soluble polymer as used in Example 
1 
EXAMPLE 7 
11.0 parts of fumed amorphous silicon dioxide 
241.0 parts of deionized water 
114.2 parts of 60% aqueous fluotitanic acid 
633.8 parts of an aqueous composition prepared from the following 
ingredients: 
5.41% of CrO.sub.3 
0.59% of pearled corn starch 
94% of water 
EXAMPLE 8 
666.0 parts of deionized water 
83.9 parts of 60% aqueous fluotitanic acid 
5.3 parts of Cab-O-Sil.TM. M-5 fumed amorphous silicon dioxide 
14.8 parts of zirconium basic carbonate 
230.0 parts of RDX 68654.TM. (also known as RIX 95928.TM.) epoxy resin 
dispersion commercially available from Rhone-Poulenc, containing 40% 
solids of polymers of predominantly diglycidyl ethers of bisphenol-A, in 
which some of the epoxide groups have been converted to hydroxy groups and 
the polymer molecules are phosphate capped 
EXAMPLE 9 
656.0 parts of deionized water 
183.9 parts of 60% aqueous fluotitanic acid 
5.3 parts of Cab-O-Sil.TM. M-5 fumed amorphous silicon dioxide 
14.8 parts of zirconium basic carbonate 
240.0 parts of Accumer.TM. 1510, a commercially available product from Rohm 
& Haas containing 25% solids of polymers of acrylic acid with a molecular 
weight of 60,000 
EXAMPLE 10 
636.2 parts of deionized water 
83.7 parts of 60% aqueous fluotitanic acid 5.3 parts of Cab-O-Sil.TM. M-5 
fumed amorphous silicon dioxide 
14.6 parts of zirconium basic carbonate 
37.6 parts of the 10% solution of water soluble polymer as used in Example 
1 
222.6 parts of Accumer.TM. 1510, a commercially available product from Rohm 
& Haas containing 25% solids of polymers of acrylic acid with a molecular 
weight of 60,000 
For each of Examples 1-6 and 8-10, the ingredients were added in the order 
indicated to a container provided with stirring. (Glass containers are 
susceptible to chemical attack by the compositions and generally should 
not be used, even on a laboratory scale; containers of austenitic 
stainless steels such as Type 316 and containers made of or fully lined 
with resistant plastics such as polymers of tetrafluoroethene or 
chlorotrifluoroethene have proved to be satisfactory.) In each of these 
Examples except Example 4, after the addition of the silica component and 
before the addition of the subsequently listed components, the mixture was 
heated to a temperature in the range from 38.degree.-43.degree. C. and 
maintained within that range of temperatures for a time of 20-30 minutes. 
Then the mixture was cooled to a temperature below 30.degree. C., and the 
remaining ingredients were stirred in without additional heating, until a 
clear solution was obtained after each addition. 
For Example 4, the SiO.sub.2 used was surface modified with a silane, and 
because of its hydrophobic nature, the mixture containing this form of 
silica was heated for 1.5 hours at 70.degree. C. to achieve transparency. 
The remaining steps of the process were the same as for Example 1. 
For Example 7, the first three ingredients listed were mixed together and 
maintained at 40.degree..+-.5.degree. C. for 20-30 minutes with stirring 
and then cooled. In a separate container, the CrO.sub.3 was dissolved in 
about fifteen times its own weight of water, and to this solution was 
added a slurry of the corn starch in twenty-four times its own weight of 
water. The mixture was then maintained for 90 minutes with gentle stirring 
at 88.degree..+-.6.degree. C. to reduce part of the hexavalent chromium 
content to trivalent chromium. Finally, this mixture was cooled with 
stirring and then added to the previously prepared heated mixture of 
fluotitanic acid, silicon dioxide, and water. This composition is used in 
the manner known in the art for compositions containing hexavalent and 
trivalent chromium and dispersed silica, but it is much more stable to 
storage without phase separation. 
Comparative Example 1 
18.9 parts of aqueous 60% fluotitanic acid 
363.6 parts of the 10% solution of water soluble polymer as used in Example 
1 
617.5 parts of deionized water 
Comparative Example 2 
18.9 parts of aqueous 60% fluotitanic acid 
71.8 parts of the 10% solution of water soluble polymer as used in Example 
1 
909.3 parts of deionized water 
For Comparative Examples 1 and 2 the components were added together with 
agitation in the order indicated, with no heating before use in treating 
metal surfaces. 
Add-on mass levels, specific paints used, and test results with some of the 
compositions described above are shown in Tables 1-5 below. 
TABLE 1 
______________________________________ 
Panels Painted with PPG Duracron .TM. 1000 White Single Coat Acrylic 
Paint 
HAc Salt 
Boiling Water Coating Spray Humidity 
Treatment 
2T Bend Impact Weight 504 Hours 
1008 Hrs. 
______________________________________ 
Example 1 
9 10 65 mg/m.sup.2 
e 0-1.sup.s 
Vf9 
as Ti s 0-1.sup.s 
" 9 10 43 mg/m.sup.2 
e 0-1.sup.s 
Vf9 
as Ti s 0-1.sup.s 
Comparative 
5 7 39 mg/m2 
e 0-1.sup.s 
D9 
Example 1 as Ti s 0-2.sup.s 
Comparative 
0 0 27 mg/m.sup.2 
e 0-1.sup.s 
D9 
Example 1 as Ti s 0-2.sup.s 
Comparative 
7 8 65 mg/m.sup.2 
e 0-1.sup.s 
Vf9 
Example 2 as Ti s 0-1.sup.s 
Comparative 
4 6 29 mg/m.sup.2 
e 0-1.sup.s 
Fm9 
Example 2 as Ti s 0-1.sup.s 
______________________________________ 
TABLE 2 
______________________________________ 
Panels Painted with Lilly .TM. Black Single Coat Polyester 
Salt 
HAc Salt 
Spray Humid- 
Treat- Boiling Water 
Coatin Spray 504 
1008 ity 1008 
ment 2T Bend Impact Weight 
Hours Hours Hrs. 
______________________________________ 
Example 
10 10 54 mg/ 
e 0-1.sup.s 
e N 
2 m.sup.2 as Ti 
s N s N Vf.sup.9 
Example 
10 10 64 mg/ 
e 0-2.sup.s 
e 0-1.sup.s 
3 m.sup.2 as Ti 
s 0-2.sup.s 
e N Vf.sup.9 
______________________________________ 
TABLE 3 
______________________________________ 
Panels Painted with Lilly .TM. Colonial White Single Coat Polyester 
Salt 
Boiling Water HAc Salt 
Spray 
Treat- 2T Coating 
Spray 504 
1008 Humidity 
ment Bend Impact Weight Hours Hours 1008 Hrs. 
______________________________________ 
Example 4 
5 8 65 mg/m.sup.2 
e N e N 
as Ti s N s N Vf.sup.9 
Example 5 
10 10 22 mg/m.sup.2 
e N e N 
as Ti s N s N Vf.sup.9 
Example 5 
10 10 54 mg/m.sup.2 
e N e N 
s N s N Vf.sup.9 
Example 6 
10 10 22 mg/m.sup.2 
e 0-1.sup.s 
e N 
s N s N Vf.sup.9 
Example 6 
10 10 54 mg/m.sup.2 
e 0-1.sup.s 
e N 
s N s N Vf.sup.9 
Example 8 
9.8 10 12 mg/m.sup.2 
e N e N 
s 0-1.sup.s 
s N N 
Example 8 
9.6 10 24 mg/m.sup.2 
e N e N 
s 0-1.sup.s 
s N N 
Example 9 
10 10 11 mg/m.sup.2 
e N e N 
s 0-1.sup.s 
s 0-1.sup.s 
N 
Example 9 
9.8 10 24 mg/m.sup.2 
e 0-1.sup.s 
e N 
s 0-1.sup.s 
s 0-1 N 
Example 
9.8 9.8 17 mg/m.sup.2 
e 0-1.sup.s 
e N 
10 s 0-1.sup.s 
s N Vf.sup.9 
Example 
9.9 10 25 mg/m.sup.2 
e 0-1.sup.s 
e N 
10 s 0-1.sup.s 
s N Vf.sup.9 
Example 
9.9 10 33 mg/m.sup.2 
e 0-1.sup.s 
e N 
10 s 0-1.sup.s 
s N Vf.sup.9 
______________________________________ 
TABLE 4 
______________________________________ 
Panels Painted with Valspar/Desoto .TM. White Single Coat Polyester 
Salt 
Boiling Water HAc Salt 
Spray 
Treat- 2T Coating 
Spray 504 
1008 Humidity 
ment Bend Impact Weight Hours Hours 1008 Hrs. 
______________________________________ 
Example 
10 10 39 mg/m.sup.2 
e 0-1.sup.s 
e N 
2 as Ti s 0-1.sup.2 
s N Vf.sup.9 
Example 
10 10 48 mg/m.sup.2 
e 0-1.sup.s 
e N 
2 as Ti s 0-1.sup.s 
s N Vf.sup.9 
Example 
10 10 70 mg/m.sup.2 
e 0-2.sup.s 
e N 
2 as Ti s 0-1.sup.s 
s N Vf.sup.9 
Example 
10 10 87 mg/m.sup.2 
e N e 0-1.sup.s 
2 as Ti s 0-1.sup.s 
s N Vf.sup.9 
Example 
10 10 29 mg/m.sup.2 
e 0-2.sup.s 
e N 
3 as Ti s 0-1.sup.s 
s N Vf.sup.9 
Example 
10 10 42 mg/m.sup.2 
e 0-1.sup.s 
e N 
3 as Ti s 0-1.sup.s 
s N Vf.sup.9 
Example 
10 10 57 mg/m.sup.2 
e 0-1 e N 
3 as Ti s 0-1.sup.s 
s N Vf.sup.9 
Example 
10 10 82 mg/m.sup.2 
e 0-2.sup.s 
e 0-1.sup.s 
3 as Ti s 0-2.sup.s 
s N Vf.sup.9 
Example 
7 10 65 mg/m.sup.2 
e 0-1.sup.s 
e N 
4 as Ti s 0-1.sup.s 
s N Vf.sup.9 
______________________________________ 
TABLE 5 
______________________________________ 
Panels Painted with Valspar .TM. Colonial White Single Coat Polyester 
Salt 
Boiling Water HAc Salt 
Spray 
Treat- 2T Coating 
Spray 504 
1008 Humidity 
ment Bend Impact Weight Hours Hours 1008 Hrs. 
______________________________________ 
Example 
10 10 54 mg/m.sup.2 
e N e N 
2 as Ti s N s N Fm.sup.9 
Example 
10 10 64 mg/m.sup.2 
e 0-1.sup.s 
e 0-1.sup.s 
3 as Ti s N s 0-1.sup.s 
Fm.sup.9 
______________________________________ 
The storage stability of the compositions according to all of the examples 
above except Example 2 was so good that no phase separation could be 
observed after at least 1500 hours of storage. For Example 2, some 
settling of a slight amount of apparent solid phase was observable after 
150 hours. 
GROUP II 
TREATMENT WITH COMPOSITIONS CONTAINING NECESSARY COMPONENTS (A) AND (B), 
WITH SUBSEQUENT RINSING 
To obtain the results reported below, an alternative process of treating 
the metal surfaces according to the invention and different aluminum 
alloys were used. Specifically, in part I of this Group, test pieces of 
Type 5352 or 5182 aluminum were spray cleaned for 10 seconds at 
54.4.degree. C. with an aqueous cleaner containing 24 g/L of CO.RTM. 
Cleaner 305 (commercially available from the Parker+Amchem Division of 
Henkel Corp., Madison Heights, Mich., USA). After cleaning, the panels 
were rinsed with hot water; then they were sprayed with the respective 
treatment solutions according to the invention, which were the same as 
those already described above with the same Example Number, except that 
they were further diluted with water to the concentration shown in the 
tables below, for 5 seconds; and then were rinsed successively with cold 
tap water and deionized water and dried, prior to painting. 
The "0T Bend" column in the following tables reports the result of a test 
procedure as follows: 
1. Perform a 0-T bend in accordance with ASTM Method D4145-83. 
2. Firmly apply one piece of #610 Scotch.RTM. tape to the area of the test 
panel with the 0-T bend and to the adjacent flat area. 
3. Slowly pull the tape off from the bend and the adjacent flat area. 
4. Repeat steps 2 and 3, using a fresh piece of tape for each repetition, 
until no additional paint is removed by the tape. 
5. Report the maximum distance from the 0-T bend into the flat area from 
which paint removal is observed according to the scale below: 
______________________________________ 
Paint loss in mm 
Rating 
______________________________________ 
0 5.0 
0.20 4.9 
0.30 4.8 
0.8 4.5 
1.6 4.0 
2.4 3.5 
3.2 3.0 
4.0 2.5 
4.8 2.0 
5.6 1.5 
6.4 1.0 
7.2 0.5 
&gt;7.2 0 
______________________________________ 
The "Ninety Minute Steam Exposure" columns of the tables below report the 
results of tests performed as follows: 
1. Expose the painted samples to steam at a temperature of 120.degree. C. 
steam for 90 minutes in a pressure cooker or autoclave. 
2. Crosshatch the painted sample--two perpendicular cuts; a Gardner 
crosshatch tool with 11 knife edges spaced 1.5 mm apart was used. 
3. Firmly apply #610 Scotch.TM. tape to the crosshatched area and remove 
tape. 
4. Examine the crosshatched area for paint not removed by the tape and 
report a number representing one-tenth of the percentage of paint 
remaining. 
5. Using a microscope at 10-80 times magnification, visually observe 
crosshatched area for blistering, and rate size and density of blisters. 
The "15 Minute Boiling DOWFAX.TM. 2A1 Immersion" columns of the tables 
below report the results of tests performed after treatment as follows: 
1. Prepare solution of 1% by volume of DOWFAX.TM. 2A1 in deionized water 
and bring to boil. 
2. Immerse painted test panels in the boiling solution prepared in step 1 
and keep there for 15 minutes; then remove panels, rinse with water, and 
dry. 
DOWFAX.TM. 2A1 is commercially available from Dow Chemical and is described 
by the supplier as 45% active sodium dodecyl diphenyloxide disulfonate. 
The "Cross Hatch" test after this treatment was made in the same way as 
described above for steps 2-4 after "Ninety Minute Steam Exposure". The 
"Reverse Impact" test was made as described in ASTM D2794-84E1 (for 20 
inch pounds impact), then proceeding in the same way as described above 
for steps 3-4 after "Ninety Minute Steam Exposure". The "Feathering" test 
was performed as follows: Using a utility knife, scribe a slightly curved 
"V" on the back side of the test panel. Using scissors, cut up about 12 
millimeters from the bottom along the scribe. Bend the inside of the V 
away from side for testing. Place sample in a vise and, using pliers, pull 
from the folded section with a slow continuous motion. Ignore the part of 
the panel between the top edges nearest to the vertex and a line parallel 
to the top edge but 19 mm away from it. On the remainder of the panel, 
measure to edge of feathering in millimeters. Record the largest value 
observed. 
The results of tests according to these procedures are shown in Tables 6-8 
below. 
TABLE 6 
______________________________________ 
5352 Alloy Panels Painted with Valspar .TM. S-9009-139 Paint 
Inven- Ninety Minute 
tion Steam Exposure 
Compo- Concen- Coating Cross Blist- 
sition tration pH Weight OT Bend 
Hatch ering 
______________________________________ 
Example 
1% 2.7 4.0 5 10 Very 
1 mg/m.sup.2 few, 
as Ti small- 
medium 
Example 
1% 3.2 11.4 5 10 few, 
1 mg/m.sup.2 small 
as Ti 
Example 
3% 2.5 2.3 5 10 very 
1 mg/m.sup.2 few, 
as Ti very 
small 
Clean N/A 1.5 10 few, 
only medium 
(Com- 
pari- 
son) 
______________________________________ 
TABLE 7 
______________________________________ 
5352 Alloy Panels Painted with Valspar .TM. S-9009-154 Paint 
Inven- Ninety Minute 
tion Steam Exposure 
Compo- Concen- Coating Cross Blist- 
sition tration pH Weight OT Bend 
Hatch ering 
______________________________________ 
Example 
1% 2.9 4.2 5 9-10 Very 
1 mg/m.sup.2 few, 
as Ti small 
Example 
3% 2.7 2.6 5 9-10 very 
1 mg/m.sup.2 few, 
as Ti very 
small 
______________________________________ 
TABLE 8 
______________________________________ 
5182 alloy panels Painted with Valspar .TM. S-9835002 Paint 
Inven- 15 Minute Boiling 
tion DOWFAX .TM. 2A1 Immersion 
Compo- Concen- Coating Cross Reverse 
sition tration pH Weight Hatch Impact 
Feathering 
______________________________________ 
Example 
1% by 2.9 7.9 mg/m.sup.2 
10 10 0.35 mm 
1 weight as Ti 
______________________________________ 
In part II of this Group, Type 5352 aluminum was used, and the process 
sequence used in part I, except for final drying, was used but was then 
followed by passing the test pieces, still wet from the deionized water 
rinse after contact with a composition according to this invention, 
through power driven squeegee rolls arranged so that the test pieces 
passed through the squeegee rolls in a horizontal position immediately 
after being sprayed liberally with the final treatment liquid composition 
at a temperature of 60.degree. C. before being dried. In Examples 11 and 
13 the treatment liquid in this final stage was simply deionized water 
with a conductivity of not more than 4.0 .mu.Siemens/cm, while in Example 
12 the treatment liquid in this final stage was obtained by mixing 35 ml 
of Parcolene.TM. 95AT and 2.0 ml of Parcolene.TM. 88B with 7 liters of 
deionized water and had a pH of 5.18 and a conductivity of 56 
.mu.Siemens/cm. (Both Parcolene.TM. products noted are commercially 
available from the Parker+Amchem Div. of Henkel Corp., Madison Heights, 
Mich.) This latter type of final treatment liquid is an example of one 
containing polymers and/or copolymers of one or more x-(N--R.sup.1 
--N--R.sup.2 -aminomethyl)-4-hydroxy-styrenes as already described above. 
Concentrate II--II used in each of Examples 11-13 had the following 
composition: 
1892.7 parts of deionized water 
83.7 parts of 60% aqueous fluotitanic acid 
5.3 parts of Cab-O-Sil.TM. M-5 fumed amorphous silicon dioxide 
18.3 parts of zirconium basic carbonate. 
These ingredients were simply mixed together with mechanical agitation in 
the order shown, with a pause after each addition until the solution 
became optically clear. Although the partial mixture was not transparent 
immediately after addition of the silicon dioxide, it became clear after a 
few minutes of mixing, even without any heating. 
The working solution for Examples 11 and 12 was prepared by diluting 200 
grams of the concentrate II--II, along with sufficient sodium carbonate to 
result in a pH of 2.92.+-.0.2, to form 6 liters of working composition. 
For Example 13, the working solution was made in the same way, except that 
it also contained 5 grams of a concentrated polymer solution made 
according to the directions of column 11 lines 39-49 of U.S. Pat. No. 
4,963,596, except as follows: The preparation was carried out on a 
substantially larger scale; the proportions of ingredients were changed to 
the following: 241 parts of Propasol.TM. P, 109 parts of Resin M, 179 
parts of N-methylglucamine, 73.5 parts of aqueous 37% formaldehyde, and 
398 parts of deionized water, of which 126 parts were reserved for a final 
addition not described in the noted patent, with the remainder used to 
slurry the N-methylglucamine as noted in the patent; and the temperature 
noted as 60.degree.-65.degree. C. in the patent was reduced to 57.degree. 
C. 
The dried test panels were then coated with Valspar.TM. 9009-157 paint 
according to the directions of the paint supplier, and the paint coated 
panels were tested as described for the tests of the same name in part I 
of Group II. Results are shown in Table 9. 
TABLE 9 
______________________________________ 
Example 90 Minute Steam Exposure 
Number mg of Ti/m.sup.2 
O-T Bend Cross Hatch 
Blistering 
______________________________________ 
11 3.6 4.5 10 4.5 
12 4.6 4.9 10 4.5 
13 5.4 4.8 10 4.0 
______________________________________ 
In part III of Group II, Type 2024-T3 aluminun alloy was used as the 
substrate metal to be treated according to the invention. Test panels of 
this alloy were cleaned by immersion for 3 minutes at 65.degree. C. in an 
aqueous solution containing 15 grams per liter (hereinafter usually 
abbreviated as "g/L") of RIDOLENE.RTM. 53 Cleaner concentrate, a 
commercial silicated alkaline cleaner product available from the Parker 
Amchem Division of Henkel Corp., Madison Heights, Mich. USA, then rinsed 
in hot water, then deoxidized by immersion for 5 minutes in a liquid 
composition of Deoxidizer 6-16, commercially available from the Parker 
Amchem Division of Henkel Corp., Madison Heights, Mich. USA, then rinsed 
in cold water, then immersed at 27.degree. C. in a working composition 
according to the invention that had been prepared as follows: 24.1 grams 
of aqueous fluotitanic acid containing 60% of H.sub.2 TiF.sub.6, 9.5 grams 
of solid zirconium basic carbonate containing 40% of Zr, 3.4 grams of 
amorphous silicon dioxide (Cab-O-Sil.TM. M-5, commercially available from 
Cabot Corp., and 168.5 grams of deionized water were agitated together at 
a temperature of 40.degree. C. for a time of 30 minutes, so that a liquid 
composition with no visible settling of solids therefrom was produced. 
This liquid composition was then diluted with 2 liters of deionized water, 
and 0.12 grams of sodium chloride, 5.83 grams of sodium nitrate, and 27.6 
grams of sodium dichromate dihydrate were then dissolved in this diluted 
mixture. Finally, the volume of the mixture was increased to 3.9 liters by 
adding more deionized water. 
Panels that had been cleaned, rinsed, deoxidized, and again rinsed as 
described above were immesed in the composition noted in the immediately 
preceding paragraph while this composition was maintained at 27.degree. C. 
for either 3 or 5 minutes. Resulting coating mass add-ons were 130 and 140 
mg/m.sup.2 respectively. After exposure to 436 hours of salt spray testing 
according to American Society for Testing and Materials Test, panels 
exposed for both intervals of time had no visible pits or discoloration. 
GROUP III, WITH NECESSARY COMPONENTS (A') AND (B') 
EXAMPLE 14 
A first concentrate was made by mixing 750 parts of tap water and 274 parts 
of Acrysol.TM. A-1, a commercially available product from Rohm and Haas 
containing 25% solids of polymers of acrylic acid with a molecular weight 
of less than 50,000. A second concentrate was made by mixing, in a 
container separate from that used for the first concentrate 951.3 parts of 
tap water and 66.7 g/l of Gohsenol.TM. GLO-5, a commerically available 
product from Nippon Gohsei which is a low molecular weight polyvinyl 
alcohol; the latter was added to the tap water with stirring at a slow and 
controlled flow, after which the temperature was increased to 
49.degree.-54.degree. C. for 30 minutes with slow stirring until all was 
dissolved. 
An amount of these concentrates equal, for each concentrate separately, to 
6 volume % of the final volume of composition ready for treating a metal 
surface according to this invention, was then added with stirring at 
ambient temperature to a large excess of water, and after addition of both 
concentrates, additional water was added to reach the final volume of 
treatment composition, which contained 4.1 g/l of polyacrylic acid and 4.0 
g/l of polyvinyl alcohol. 
This composition was then contacted with an aluminum surface by dipping or 
spraying for a time from 30 to 60 seconds, after which time the surfaces 
treated were removed from contact with the treating composition, allowed 
to dry in the ambient atmosphere without rinsing, and then baked in a warm 
air oven at 88.degree. C. for 5 minutes to simulate commercial operating 
conditions. The surfaces thus prepared were painted with conventional 
paints. 
EXAMPLES 15-20 
In each of these examples, the treating composition is prepared in the same 
general manner as in Example 14, by making separate concentrates of the 
hydroxyl group containing polymer and polyacrylic acid components, mixing 
an appropriate amount of these concentrates with a larger volume of water, 
adding any additional components used, and finally adjusting to the final 
desired volume or mass by the addition of more water. These compositions 
are then applied to aluminum surfaces in the same manner as described for 
Example 14. The specific active ingredients and concentrations or amounts 
thereof in the treatment composition for each example are as follows: 
EXAMPLE 15 
4.1 g/l of Acrysol.TM. A-1; 4.0 g/l of Gohsenol.TM. GLO-5; and 1.2 g/l of 
hexafluorozirconic acid. 
EXAMPLE 16 
4.1 g/l of Acrysol.TM. A-1 and 0.6 g/l of polyethylene glycol having a 
molecular weight of less than about 600,000. 
EXAMPLE 17 
4.1 g/l of Acrysol.TM. A-1; 0.6 g/l of polyethylene glycol having a 
molecular weight of less than about 600,000; and 1.2 g/l of 
hexafluorozirconic acid. 
EXAMPLE 18 
4.1 g/l of Acrysol.TM. A-1 and 0.8 g/l of dextrin. 
EXAMPLE 19 
4.1 g/l of Acrysol.TM. A-1; 0.8 g/l of dextrin; and 1.2 g/l of 
hexafluorotitanic acid. 
EXAMPLE 20 
651.4 parts of deionized water; 83.7 parts of 60% aqueous fluotitanic acid; 
5.3 parts of Cab-O-Sil.TM. M-5 fumed amorphous silicon dioxide; 14.6 parts 
of zirconium basic carbonate; 200.0 parts of Accumer.TM. 1510, a 
commercially available product from Rohm and Haas containing 25% solids of 
polymers of acrylic acid with a molecular weight of about 60,000; and 55.0 
parts of Gohsenol.TM. GLO-5.