Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
104~872
BACKGROUND OF THE INVENTION
In the art of treating metal surfaces, it is common
practice to improve the corrosion resistance characteristics and
paint bonding qualities of a metal surface by depositing a conversion
coating or the like thereon. In order to improve the qualities
of the already applied protective coating or conversion coating,
it is common practice to subsequently treat the metal surface after
the conversion coating has been formed thereon. To enhance the
corrosion resistance of an unpainted metal surface, or to prepare
a metal surface for the reception of a final finish or siccative
coating, such as a paint, enamel~ or sanitary lacquer, various
coating methods and compositions have been employed. For example,
compositions consisting essentially of aqueous acid phosphate or
acid chromate solutions have been employed to treat bare metal
surfaces already possessing a conversion coating to improve the
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1046872
corrosion resistance and paint bonding characteristics.
Chromate treatments employed to deposit a coating on a metal
surface or as a treatment after a conversion coating has been
formed thereon are disclosed, for example in United States -
Patent Nos. 2,825,697; 2,678,291; 2,936,254 and 2,928,763. ~-
An important shortcoming, which treatments of the kind
to which reference has been made possess, is the inherent tox-
icity and presence of noxious~materials in the effluents, such
as hexavalent chromium, phosphates, and fluorides. Waste dis-
posal problems, handling problems, and difficulties due to thecorrosive action of the composition on ~he equipment employ-
ed are created by the presence of acidic components in the bath
effluent.
Another problem encountered with chromium containing
treatments is that certain paint or lac~uer systems will chip,
peel, or blister when applied to a metal surface which has been
treated with chromates. Workpieces having complex configura-
tions will accumulate residues of chromium salts in areas such
as crevices, pockets and joints. These areas will tend to dis-
play blistering, peeling, and generally inferior siccativefinish adhesion.
Resinous materials have been incorporated in a chromate
treating solution, so as to provide on the metal surface a
final finish or an excellent base for subse~uent painting.
Solutions and dispersions of this kind are disclosed, for exam-
ple, in United States Patent Nos. 2,902,3gO; 3,053,692;
3,132,055; 3,185,596; 3,189,488 and 3,189,489. However, these
treating solutions and the protective coatings formed therefrom
have not eliminated the detrimental effect of the high toxicity
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~3~6872
associated with hexavalent chromium.
The primary object of the present invention is to provide a
method for the treatment of metal surfaces which will enchance the corrosion
resistance and siccative finish bonding characteristics of the surface.
An added object of this invention is to provide a process and
treating composition for metal surfaces which enhance the adhesion properties
of a subsequently applied siccative finish while eliminating the waste efflu-
ent disposal problems encountered with compositions employed heretofore.
A concomitant object of this invention is to provide an improved
method for treating metal surfaces on which a conversion coating has already
been deposited.
DETAILED DESCRIPTION OF THE INVENTION
I have discovered a chrome-free process and composition for
treating the surfaces of metals such as iron, steel, zinc, aluminum and alloys
in which they are the predominant constituent. The aqueous composition em-
ployed in the present process consists essentially of a soluble zirconium
compound and a polymeric material. When the composition is applied to metal
substrate, a coating is obtained which enhances corrosion resistance and
siccative finish bonding.
Thus this invention seeks to provide a process for treating a
metallic surface to improve the corrosion resistance and the siccative finish
bonding characteristics of said surface which comprises contacting said sur-
face with an aqueous composition consisting essentially of a soluble zirconium
compound in an amount of from about 0.1 grams/liter to about 3.5 grams/liter,
measured as ZrO2, and a polymeric material in an amount of from about 0.1
grams/liter to about 5.0 grams/liter.
It should be understood that the term "aqueous composition" or
"aqueous solution" utilized herein means the aqueous admixture comprising
zirconium, present as a soluble zirconium compound, and a polymeric material.
The concentration of zirconium present in the aqueous composition is expressed
herein as the concentration of ZrO2. This means that the zirconium, present
as a soluble zirconium compound in solution, is in the
-- 3 --
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: .
1046~372
form of tetravalent zirconium whose concentration is expressed
as the concentration of its oxide. Although the resinous or
polymeric material may be present in the aqueous composition
either in dissolved form, emulsion form, or in the form of in-
soluble particles dispersed in the composition, the term
"aqueous solution" when employed herein is to be understood
as including an emulsion or dispersion of the polymer and zir-
conium compound, as well as a solution of the polymer and zir-
conium compound. Examples of water soluble polymeric or resin-
10 ous materials that can be utilized are polyacrylic acid, poly-
vinyl alcohol, hydroxyethyl ethers of cellulose, ethylene maleic
anhydride, polyvinyl pyrollidine, and polyvinyl methyl ether.
An example of a polymeric material in the form of dispersed
particles that can be utilized is an acrylic copolymer latice. -
Of course, the dispersed polymer or late~ should be stable, in
the presence of the other ingredients comprising the aqueous
composition.
A wide variety of soluble zirconium compounds can be
employed. The selection of the compound to be employed will
20 depend on its commercial availability and its stability in
solution with the polymeric material. It is, of course,
necessary that upon its inclusion in the aqueous solution, it
should not hydrolize to insoluble hydrous zirconium dioxide or
an insoluble zirconium salt at the operating p~ and temperature
of the process, nor should it cause coagulation of the polymeric
material.
Typical examples of zirconium compounds which can be
employed in the aqueous composition are alkali metal and ammon-
ium fluozirconate and ammonium zirconium carbonate. The
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a~ueous composition should comprise at least 0.1 grams/liter of
the zirconium compound (measured as ZrO2). In the preferred em-
bodiment, ammonium zirconium carbonate will be employed in the
aqueous composition and its concentration, measured as ZrO2 will
preferably be from about 0.1 grams/liter to about 3.5 grams/
liter.
As has been suggested hereinabove, the resinous or
polymeric material may include both water soluble as well as
water dispersible polymers. In the preferred embodiment of
10 this invention, the aqueous composition comprises a water sol- `
uble polyacrylic acid. Water dispersible emulsions or latexes
of polyacrylic acid derivatives are also commerically available, -;
such as the alkali metal and ammonium salts of polyacrylic acid, ~-
and the polyacrylic acid esters. By the term"acrylic acid
polymer" or "polyacrylic acid", it should be understood that
this means and applies to all types o polymers to be utilized
in the aqueous composition, whether they be water dispersible
or water soluble salts, esters, or the acid. Aqueous solutions
of polyacrylic acid are available commercially, for example,
those sold under the name Acryso~ A-l, Acrysol*A-3, and
Acrysol*A-5. Water dispersible emulsions of polyacrylic acid
esters are also available, for example those sold under the
name Rhoplex*Ac-35.
The amount of polymer utilized can vary over a wide
range. It is preferred that the polymeric material in the
aqueous composition be present in an amount from about 0.1
grams/liter to about ~.0 grams/liter. Naturally, the amount of - -
polymeric material present in the solution must be sufficient
to aid in the forming of a film on the metal surface. A
* Trademark
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6872
surprising aspect of the present invention is that an a~ueous
composition having a concentration of polymeric material within
the preferred range indicated above gives satisfactory uniform
coatings which adhere to the surface and improve the siccative
finishing bonding characteristics of the surface. It is ap-
parent that the amount of polymer present should be that amount
which will be particularly effective under the particular operat-
ing conditions of the treating process, so as to improve the
corrosion resistant capabilities and siccative finish bonding
properties of the already formed coating, or in the case where
no coating has been deposited, to improve the corrosion resis-
tance of the bare metal surface and its paint bonding charac-
teristics. It has been found that the amount of polymeric ma-
terial should preferably range from about 1.0 part to about 2.0
parts by weight for each part by weight of zirconium in the
aqueous composition.
~ t should be noted that the combination of a zirconium
compound and polymeric material is more effective, in terms
of corrosion resistance and paint bonding characteristics, than
the individual constituents when applied to a metal surface.
This effect will be evident from the examples included herein-
below.
As already set forth herein, any polymeric material
which is stable in the presence of the zirconium compound in a
water-based composition can be used in the practice of this
invention. The aqueous compositions to be used preferably~are
prepared by addition of the components to water. This negates
any problems with respect to stability for prolonged periods
of time should an aqueous concentrate be prepared and then
r ~ --6--
~ 04687Z
added directly to water in order to prepare the aqueous composi-
tion for use. It has been observed that, u~der certain condi-
tions, should an aqueous concentrate be prepared to make up the
aqueous composition, hydrolysis and salting out of both the
zirconium compound and the polym~r is evident.~ of course, to
prepare the composition each constituent is preferably added -~
to the appropriate amount of water to prepare a working bath
having constituent concentrations within the operative ranges
set forth herein.
preferably, the zirconium compound and polymer will
evidence stability by remaining uniformly distributed through-
out the aqueous phase of the composition, although in certain
cases stirring of the composition may be employed to maintain a
uniform dispersion during operation. In the preferred embodi-
ment of the invention, the polymeric material should already be
in solution or dispersed in the aqueous phase prior to the
addition of the zirconium compound. This will further insure
against any hydrolysis and precipitation of zirconium in the
prepared aqueous bath.
It has been observed that should the concentration of
polymeric material be less than 0.1 grams/liter no substantial
improvement in the siccative finish bonding properties will
result. In the preferred embodiment of this invention, with
respect to the upper concentation limit of polyacrylic acid, it
has been found that no additional improvement over those obtain-
ed initially is experienced by the use of more than about 5.0
grams/liter of the polyacrylic acid. The polymeric material by
itself has little or no value, but combination of the polymer and
the zirconium compound, as described herein, gives excellent and
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1~4~;872
unexpected corrosion resistance and siccative finish bonding
characteristics.
prior to treatment with the aqueous composition, the
metal surface can be treated with a solution which reacts with
the surface to form a conversion coating. The conversion coat-
ing will have been applied using commonly employed processes
and techniques known to the art. Particularly, the conversion
coatings employed are those referred to as chromate`coatings or
phosphate coatings. By chromate coatings, we mean those pro- -
duced from aqueous baths containing hexavalent chromium, tri-
valent chromium, and/or salts thereof, as well as additional
constituents such as phosphoric acid, and fluoride. By phosphate
coatings, we mean those produced from aqueous solutions contain-
ing phosphoric acid and salts thereof, as well as additional
constituents such as fluorides, molybdates, chlorates, nitrates,
and various organic accelerators.
Formula 1 is an example of a suitable dry chromate
coating composition which can be added to water to form a
chromate coating solution which can be employed to treat metal
surfaces prior to their treatment with the aqueous composition:
Formula 1
% by Weight
Chromic Acid 33_37
Potassium Fluozirconate 15-16
Sodium Bifluoride 45-49
Formula 2 is an example of a suitable concentrated
chromate-phosphate coating solution which can be diluted to
desired strength with an aqueous hydrofluoric acid solution and
can beemployed to treat a~uminum surfaces forming a chromate-
phosphate coating thereon, prior to the treatment with theaqueous composition.
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Formula 2
% by Weight
Chromic Acid 57-60
Phosphoric Acid (75%) 15-16
Water 24-26
Formula 3 is an example of a suitable concentrated
phosphate coating solution which can be diluted to desired
strength and can be employed to treat metal surfaces prior to
contact with the aqueous composition.
Formula 3 - -
O/D by Weight
Phosphoric Acid (75%) 2-4
Ammonium Hydroxide (26Be) 1-2
Ammonium Bifluoride .1-.8
Ammonium Molybdate .1-.3
Water 93-96
A surprising aspect of the present invention has been `~
observed when the aqueous composition is employed subsequent
to treatment with a coating solution as described in Formula 3
hereinabove. A coating deposited by employing the coating solu-
tion prepared with Formula 3 on aluminum surfaces has the tend-
ency to discolor, for instance after exposure to boiling water.
Should coatings of this type be applied to aluminum containers
and then subjected to the conditions of pasteurization or
pasteurization procedures, such as immersion in boiling water
at 250F and 15 psi, undesirable discoloration will result~
When the aqueous composition of the present invention is
applied to aluminum surfaces having an underlying phosphate con-
version coating of the kind formed from a solution of Formula 3,
this discoloration can be prevented upon exposure of the sur-
face to the temperature and pressure conditions described above.
~: _9_
~046872
Of course, the compositions of the present invention
can be applied to a bare metal surface having no prior coating
thereon. A surprising result is that the surface will maintain
its original appearance and a coating will be produced which
will also improve the adherence of a subsequently applied
siccative finish or sanitary lacquer,such asan acrylic based
coat, and the surface will portray improved corrosion resistance.
A coating produced in the manner described herein is extremely
useful per se, since it does add corrosion resistant properties
to the metal surface. Should a siccative finish be applied to
the treated surface, unexpected improved adhesion of the applied
siccative finish is obtained.
During the coating operation, depletion of the consti-
tuents in the aqueous composition will occur at about the same
rate. These losses must be replaced to maintain the bath within
its optimum operating limits. The coating bath is maintained
within its prescribed limits with suitable additions of the
constituents in the same proportions in which these constituents
exist in the operating aqueous composition.
The preparation of the polymers suitable for use herein
is well known to the art. The acrylic acid polymer resins to
be employed in the preferred compositions of the present in-
vention are prepared by means which can be considered solution-
type polymerization processes which result in a low molecular
weight polymer. ~owever, resins made by dispersion, bulk and
suspension type polymerization processes can also be used.
One skilled in the art will be in a position to choose the
particular polymeric material to meet specific conditions and
circumstances under which the composition is to be employed.
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In the process of the present invention the metal substrate
is brought into contact with the aqueous composition under suitable con-
ditions of pH, temperature, and contact time.
The process is employed after cleaning of the metal surface has
been accomplished. The cleaning step can be carried out by conventional
methods which form no part of the present invention. A conventional
acid or alkaline cleaner can be employed followed by a water rinse.
Should the surface be heavily soiled, a detergent cleaner additive may be
employed in the cleaning step.
The time of treatment of the metal surface with the aqueous
composition need only be long enough to insure complete wetting of the
surface and can be as long as 30 minutesO Preferably, contact time be- -
tween metal substrate and solution should be from about one second to
about one minute. One of the distinct advantages of the present invention
is that suitable protection is obtained on the metal surface utilizing a
treating time of as little as one second~
The coating process can be effected by employing any of the
contacting techniques known to the art. Contact can be effected by spray,
immersion, or flow coating techniquesO Preferably the aqueous composition
will be applied to the metal by conventional spray methods.
The pH of the composition can vary over a wide range and is
influenced by the ingredients comprising the composition, particularly
the soluble zirconium compound usedO It has been found that best results
are obtained when the operating pH of the composition is from about 6~0
to about 8Ø
The process can be operated at a temperature from about 60FD
to about 120F. It is preferred to operate the process at a temperature
of from about 70Fo to about 100F~ Generally, a slight change in the
temperature will not
~ 11 -
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necessitaee substantial alteration of the treating time,
concentration parameters, or pH adjustment.
Following application of the aqueous composition, the
surface can be subjected to a drying operation. The preferred
range of temperaturesfor the drying operation is from about
60F to about 500F and, of course, the length of the drying
step will depend upon the temperature utilized.
Once the drying step has been effected, a siccative
finish, such as a lacquer, can be applied to the surface with
10 considerable adhesion improvement. After the drying step and
application of a siccative finish, the workpiece is ready for
use and is highly resistant to corrosive attack, such as from
any liquid or foodstuff placed in a formed metallic container
formed from the workpiece. A particular advantage of the pre-
sent invention is that after contact with the aqueous composi-
tion has been accomplished, the workpiece is resistant to
c~rrosive attack, even when subjected to prolonged exposure
to air due to processing line stoppage prior to application of
the siccative finish.
The following examples are illustrative of this inven-
tion and are not considered as limiting for other materials or
operating conditions falling within the scope of the invention
that might be substituted. Example 1 is set forth ~or the
purpose of illustrating the preparation of an aqueous composi-
tion within the purview of this invention. Examples 2 through
12 illustrate the improved results obtained employing the
aqueous composition.
In the examples, certain comparative tests, defined
hereinbelow, were effected on representative test specimens.
F, a -12-
~. .
-- ~0468~2
Reverse impact tests were performed to determine the adhesive
characteristics of an organic or siccative coating applied to
the surface. This test is commonly employed in the testing
of paints. In the reverse impact test, after the panels are
coated with an appropriate paint, the test surface is position-
ed with the painted side down and the unpainted surface is
impacted by a falling 1/2" ball with a force measured at 24
inch-pounds, thereby deforming the test surface. The impacted
area is then subjected to a tape adhesion test wherein tape
is applied firmly to the impacted surface and the tape is
allowed to sit for a specified length of time, usually about
one minute. The tape is then drawn back against itself by a
rapid pulling motion in a manner such that the tape is pulled
from the surface at the impacted area. The reverse impact
test can also be effected after the surface has undergone an
immersion test as described below.
Selected test specimens were subjected to an Immersion
Test. In this procedure, the test specimens are immersed in
deionizing water or in a solution consisting of deionized
water and 1% by volume of a li~uid detergent at 180F for 30
minutes. The specimens are then removed from the solution
and rinsed, then blotted dry. A portion of the test specimen
is immediately scribed with a cross-hatch tool having eleven
cutting blades spaced one millimeter apart. Using the cross-
hatch tool, one hundred s~uares measuring one millimeter by
one millimeter are scribed on the painted surface. This is
accomplised by drawing the scribing de~ice across the area
to be tested and then repeating the procedure by drawing the
device across the same area but at a 90~ angle to the first
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--` 104~i872
scribing. The cross-hatched area is subjected to a tape ad-
hesion test wherein tape is applied firmly to the surface
of the test panel over the entire cross-hatched area so that
no air bubbles or wrinkles are present between the tape and
the surface. The tape is allowed to set for one minute and
is then drawn back against itself with a rapid pulling motion
in a mmaner such that the tape is pulled from the surface of
the specimen.
A specific area on the test specimens which had not
been impacted or cross-hatched was also subjected to a Tape
Adhesion Test. In this test, tape is applied firmly to a
portion of the surface which has not been impacted or cross-
hatched. The tape is applied in a manner such that no air bub-
bles or wrinkles are present between the tape and the surface.
The tape is allowed to set for one minute and then drawn back
against itself with a rapid pulling motion in a manner such
that the tape is pulled from the surface of the specimen. This
tape adhesion test is referred to herein as a "Field Test".
After each test, the test specimens were evaluated and
rated, employing the rating system set forth hereinbelow.
The specimens were evaluated for paint loss or paint
failure utilizing a rating scale of 0 to 10 wherein 0 represents
complete paint loss and 10 represents no paint loss. This
quantitative determination was performed on the impacted area,
the cross-hatched area and the "field test" area of the test
specimens.
EXAMP~E 1
30 mls. of an acrylic acid polymer (Acrysol*A-l, an
aqueous solution comprising polyacrylic acid, manufactured by
Rohm and ~aas) were added to 3 liters of water. ~0 mls. of
* Trademark
' ~ -14-
` ` 1~4~872
commercially available ammonium zirconium carbonate (an aqueous
solution having a pH of about 8.5 marketed by TAM, division of
National Lead Industries, Inc., and having 9% by weight of
zirconium therein (measured as ZrO2) were then added such that
an aqueous composition comprising ammonium zirconyl carbonate
and polyacrylic acid having about 2 grams/liter of zirconium
(measured as ZrO2) was formed. The pH of the solution was
measured at 7.2.
EXAMPLE 2
3 l/2 " wide aluminum coil stock was employed in this ~ -
procedure. The aluminum coil was put into 6" long test panels.
The panels were cleaned with an alkalin~ cleaner at 160~F for
15 minutes and rinsed with water. The test panels were then
subiected to a conventional deoxidizing process and then sub-
jected to a chromate-phosphate processing sequence providing
a chromate-phosphate conversion coating on the surface. A
coating solution was prepared specified in Formula 2 hereinabove
was applied to the surface, depositing a chromate-phosphate
coating of 5-7 mg. per square foot.
One set of control panels were cleaned and deoxidized
and another set of control panels was cleaned, deoxidized, and
contacted with the above chromate-phosphate solution.
Coated test panels were immersed in an aqueous com-
position consisting of polyacrylic acid and ammonium zirconium
car~onate having a polyacrylic acid concentration of 2.7 grams/
liter and a zirconium concentration of 1.8 grams/litèr, for 15
seconds at room temperature, and allowed to air dry. The pH
of the aqueous composition was recorded at about 7.2.
All test panels, i.e. those treated with the ammonium
r C~ 15
' 1046872
zirconium carbonate and polyacrylic acid composition, as well
as the control panels, were then subjected to various testing
procedures set forth below in order to determine the effects
on the workpiece.
A "room temperature weight loss" test ~d "high tempera-
ture pressure weight loss" test were performed on the control
and test panels. In the high temperature-pressure test, the
specimens were placed in a pressure vessel having a glass -
liner therein and a carbonated beverage was poured therein.
The vessels were sealed and kept at 180~F for 5 hours in one
sequence and 24 hours in a second sequence. The control and
test specimens had been weighed prior to the test and were - -
weighed thereafter. The average wei&~t losses in milligrams
per square foot of the panels is noted in Table 1 below,
based on the observed weight loss of the groups of panels in -
each treatment sequence.
In the Room Temperature weight loss test, the control
and test panels, after weighing, were placed in the vessels
at room temperature and the beverage poured therein. Specific
groups of specimens were permitted to sit therein for 1, 2, 3,
4, 5, and 7 days, respectively. At the conclusion of the test
period, the panels were thoroughly rinsed, dried and re-weighed.
Appreciable differences in weight change were noted. The
results are listed in Table I hereinbelow.
-16-
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It will be appreciated from the results in Table 1 that
the test panels immersed in the aqueous composition gave sup-
erior and unexpected protection over the Controls in terms of
weight loss, when all test specimens were exposed to the corro-
sive effect of the beverage.
EXAMPLE 3
3" wide aluminum can stock specimens were employed in
this procedure. The specimens were cut into 6" long panels and
cleaned in an acid cleaner at 170F for one minute.
Four sets of control panels were immersed in four dif-
ferent baths comprising zirconium acetate, the baths having
zirconium concentrations of 0.5 grams/liter; 1.0 gram~liter; 1.5
grams/liter; and 2.0 grams/liter respectively (measured as zrO2).
Four sets of control panels were immersed in various ammonium
~irconium carbonate solutions having concentrations of zirconium
of 0.5 grams/liter; 1.0 gram/liter; 1.5 grams/liter and 2.0
grams/liter respectively (measured as ZrO2).
Test panels were treated with an aqueous composition
comprising ammonium zirconium carbonate and polyacrylic acid.
Four sets of test specimens were utilized in four aqueous
compositions having zirconium concentrations of 0.5 grams/
liter; 1.0 gram/liter; 1.5 grams/liter and 2.0 grams/liter and
polyacrylic acid concentrations of 0.7 grams/liter; 1.4 grams/
liter; 2.1 grams/liter; and 2.8 grams/liter respectively.
A11 test specimens were then painted with an acrylic
white paint and then were subjected to the detergent immersion
test procedure. The panels were then subjected to reverse-im-
pact, cross-hatch, and "field" tests, and the results are listed
in Table 2 below.
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1046872
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104687Z
It will be observed that the ammonium zirconyl carbon-
ate and polyacrylic acid composition gave outstanding results in
the test as compared to the control specimens.
EXAMPLE 4
Aluminum can stock was employed in this procedure. 3
inch X 6 inch panels were prepared from the can stock. The
specimens namely 4 sets of control panels were treated in the
zirconium acetate solutions as in Example 3, 4 sets of control
panels were treated with the ammonium zirconyl carbonate solu-
tions as in Example 3, and 4 sets of test panels were immersedin aqueous compositions comprising ammonium zirconyl carbonate
and polyacrylic acid therein and having the respective zircon-
ium concentrations of 0.5 grams/liter; 1.0 gram/liter and
2.0 grams/liter (measured as ZrO2) and polyacrylic acid concen-
tration of 0.7 grams/liter; 1.4 grams/liter; 2.1 grams/liter
and 2.8 grams/liter respectively. A vinyl interior lacquer was
applied to all panels and they were then subjected to a
detergent immersion procedure and then reverse-impact, cross-
hatch, and "field" testing. The results of the tests are list-
ed in Table 3 below.
t~
~ 21-
1046872
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23-
`' ` 104~87Z
EXAMPLE 5
Groups of aluminum test specimens were employed in
this procedure. The cleaned test specimens comprised 3" X 6"
panels. The panels were treated with a zirconium acetate solu-
tion, an ammonium zirconium carbonate solution, and an aqueous
composition comprising ammonium zirconium carbonate and poly-
acrylic acid having the concentration parameters indicated in
Table 4 below. The test panels were painted with an acrylic
whitepaintandw~ethen subjected to a deionized water immersion
test at 180F for 1/2 hour. They were then subjected to reverse-
impact, cross-hatch, and "field" testing. The results are list-
ed in Table 4 below.
_24-
~5~46872
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1046~Z
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1046872
EXAMPLE 6
:
3" X 6" aluminum can stock panels were used in
this procedure. The specimens were cleaned with an alkaline
cleaner at 160F for fifteen minutes. They were then rinsed
and deoxidized and then subjected to a phosphate processing
sequence providing a phosphate conversion coating on the
surface. The phosphate coating solution of Formula 3 was
applied to the test specimens.
Control panels were then painted with a white
10 acrylic paint. The control panels were then subjected to an
immersion soak test with 1% detergent solution and then sub-
jected to reverse-impact, cross-hatch, and field testing.
The results are listed in Table 5 below. ~
After deposition of the phosphate coatings, two --
sets of test panels were treated with two separate aqueous
compositions comprising ammonium zirconium carbonate and
polyacrylic acid having a zirconium concentration of 1.0
grams/liter and 2.0 grams/liter respectively and a polyacrylic
acid concentration of 1.4 grams/liter and 2.8 grams/liter
20 respectively. The test panels were then painted with the
white acrylic paint. The test panels were then subjected to
the water-soak immersion test with detergent and then sub3ected
to reverse-impact, cross-hatch, and field testing. The
results are listed in Table 5 below.
-27-
104W2
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. -28-
- ., . ~ , . . :.
104687Z
EXAMPLE 7
In this procedure aluminum test panels 3" X 6" ~
were employed. The panels were cleaned in acid cleaner at
180F for one minute. The panels were then subjected to
spray treatment with the following compositions: a) poly-
acrylic acid; b) ammonium zirconium carbonate;c) ammonium
fluozirconate; d) aqueous composition comprising polyacrylic
acid and ammonium zirconium carbonate; and e) an aqueous
~composition compris~ polyacrylic acid and ammonium fluozir-
conate. The panels were then dried at ambient temperature.
The concentrations of the particular constituents in the
respective treating compositions are listed in Table 8 below.
The panels were then treated with an acrylic
exterior paint. An additional set of control panels was
cleaned and then painted.
Thereafter, the control and test panels were
subjected to an immersion test with detergent at 180F for
30 minutes. All panels were then subjected to reverse-impact,
cross-hatch, and field testing and the results are listed in
Table 6 below.
, ~ .
~ -29-
1046872
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~6872
EXAMPLE 8
3 inch X 4 inch aluminum test panels were employ-
ed in this procedure. The panels were cleaned with an alkaline
cleaner at 180F for one minute. They were rinsed with water
and groups of the test panels were subJected to various phos-
phate processing sequences providing phosphate conversion coat-
ings on their surfaces. The phosphate coating solutions employ-
ed on the groups of test panels were as follows:
75%
Phosphoric Ammonium Sodium
Test Acid Bifluoride Molybdate
Runs g/l g/l g/l
a 9.8 1.14 0.1
b 1.2 0.29 0.1
c 3.5 0.57 0.1
d 7.0 0,86 0.1 -
e 1.2 0.29 0.1
f 3.5 0.29 0.1 -~
After each group of test panels were coated with
the particular phosphate conversion coating solutions specified
above, test panels from each group were contacted with an
aqueous composition comprising ammonium zirconium carbonate
and polyacrylic acid having a zirconium concentration of 1.8
grams/liter (measured ZrO2) and a polyacrylic acid concentration
of 2.73 grams/liter. A second set from each group of coated
panels was treated with a deionized water rinse following the
coating sequence with no further treatment thereafter. Each
set of panels was then painted with an acrylic exterior white
paint.
~r~
~ ~ -31-
`` -` ` lQ46872
The painted pa~els were then subjected to the
following tests: `
a) Immersion in water at 150~F for 30 minutes -
and then subjected to the cross-hatch test. -~
b) Immersion in a 1% detergent solution at
~' 180~F for 30 minutes and then subjected to
;,"S!.' the cross-hatch test.
;
,.~ . . :
;'
~ The table below lists the results of the tests.
.:
The specimens were qualitatively evaluated for paint loss.
The ratings appearing in Table 7 below are as follows: (+)
representing no paint loss, (0) representing slight or moderate
.," .
paint loss, and (-) representing heavy or total paint loss.
~i
~ .
Table 7
Zirconium
~;~' + .
Polyacrylic Acid Deionized Water
Test Water 1% Detergent Water 1% Detergent
~ Runs Immersion Immersion Immersion Immersion
i`l a + 0
~,20 b + + + ~
;. . c + +
d + + +
, e + + + 0 ;~
~ f +
,. .
~ .
~1,
~ EXAMPLE 9 -
,
2" X 4" tin plated steel panels were used in this
procedure. The specimens were cleaned with an alkaline cleaner
o
,`~ ` at 17~`F for one minute and rinsed. Control panels were cleaned
with the alkaline cleaner, rinsed and dried. Control panels
; were painted with a whi~e acrylic paint. Two sets o~ test
.
panels were treated with two separate a~ueous compositions
-32-
`` 113 46~72
comprising ammonium zirconium carbonate and polyacrylic acid
having a zirconium concentration of 0.5 gram/liter and 1.5
grams/liter respectively and a polyacrylic acid concentration
of 0.7 grams/liter and 2.1 grams/liter respectively. The
test panels were driedfor one minute at 400F and then painted
with white acrylic paint. Test panels, and Controls were then
subjected to the water soak immersion test with detergent
and then subjected to cross-hatch and field testing. The
results are listed in Table 8 below.
Table 8
Treatment Cross Field ~-
Hatch Test_
Controls 0 2
Ammonium Zirconyl Carbonate
and Polyacrylic Acid
ZrO~ Concentration Polyacrylic Acid
Concentration
0.5 g/l 0.7 g/l 10 9
1.5 g/l 2.1 g/l 10 9
EXAMPLE 10 -
In this procedure aluminum test panels 3" X 6"
were employed. The panels were cleaned in an acid cleaner at
180F for one minute and rinsed. Cleaned and dried Gontr
test panels were painted with a white acrylic paint.
Test panels were immersed in various aqueous
compositions comprising ammonium zirconyl carbonate and various
polymeric materials listed in Table 9 below for fifteen seconds
at room temperature. The test panels were then dried at 400F
for one minute and painted with a white acrylic paint. The con-
centrations of the par~icular constituents in the respective
aqueous compositions listed in Table 9 were 2.0 grams/liter
-33-
1~6872
of ammonium zirconium carbonate and 2.0 grams/liter of the
polymeric mater~al.
Thereafter the control and test panels were sub-
jected to an immersion test in boiling ~ater for 30 minutes. All
panels were subjected to reverse impact, cross hatch, and field
testing and the results are listed in Table 9 below.
Table 9
Ammonium zirconium Carbonate +Reverse Cross Field
~~ Polymeric Materials Impact Hatch Test
Controls
Polyacrylic Acid, (Acrysol A-l,
Rohm & Haas) 10 10 10
Polyacrylic Acid, (Acrysol A-3,
Rohm & Haas) 10 10 10
Polyacrylic Acid, (Acrysol A-5,
Rohm & Haas) 10 10 10
Polyacrylic Acid, (Goodrite*K37,
Goodrich) 10 10 10
Polyacrylic Acid, (Goodrite*K702,
Goodrich) 9 2 6
Carboxy vinyl polymer (Carbapol* ~ D
801, Goodrich) 10 10 10
Acrylic c~polymer dispersion,
(Acrysol W~4, Rohm ~ Haas) 10 10 10
Ammonium polyacrylate,
(Acrysol G110, Rohm & Haas) 4 10 10
Polyvinyl alcohol, (Lemol 5-88,
Borden) 9.8 10 9
Acrylic emulsion (Rhoplex ~V-l,
Rohm & Haas) 5 10 9
Acrylic hydrosol emulsion,
(Elvacet*~012, Du Pont) 5 3 3
Additional test panels were immersed in aqueous
compositions comprising ammonium zirconium carbonate and a
* Trademark
~, -34-
1~4687Z
polymeric material for 15 seconds at room temperature. The
specimens were then dried at 400F for one minute and painted
with a white acrylic paint. The concentration of ammonium
zirconium carbonate in the aqueous compositions was 1.0 grams/
liter and the concentration of the polymeric material was 1.0
grams/liter. All panels were subjected to an immersion test
in boiling water for 30 minutes and then subjected to the
reverse impact, cross hatch, and field test and the results
are listed in Table 10 below.
Table 10
Ammonium Zirconium Carbonate +Reverse Cross Field
Polymeric Material Impact Hatch Test
Control 0 0 0
Polyacrylic acid, (Acrysol A-l,
Rohm ~ Haas) 10 10 10
Polyvinyl alcohol, (Lemol 5-88,
Borden) 4 2 2
Polyacrylamide homopolymer,
(P250, American Cyanamid) 10 10 8
Polyvinyl Methyl ether, (Gantrez
M154, GAF) 3 10 12
Polyvinyl Pyrollidone,
(NP-K30, GAF) 1 0
Phosphated Starch, (ARD 1230,
American Maize) 9.9 10 10
~ydroxy methyl cellulose, (WP-40,
Union Carbide) 10 10 10
EXAMPLE 11
2'~ X 4" steel panels were used in this procedure.
The panels were cleaned with an alkaline cleaner at 170~F
for one min~te and rinsed. Control panels were dried and
* Trademark
-35-
1046872
painted with a white acrylic paint.
After cleaning and water rinsing, the test panels
were treated with an aqueous composition comprising ammonium -
zirconium carbonate and polyacrylic acid having a zirconium - -
concentration of 1.0 gram/liter (measured as ZrO2) and a
polyacrylic acid concentration of l.0 gram/liter. The panels
were th~ndried on~ minute at 400F. The test panels were then
painted with the white acrylic paint.
Test and control panels were subjected to the water --
soak immersion test with 1.0% detergent solution and then sub~
jected to cross hatch and field testing. The results are ~ -
listed in Table 11 below.
Table 11
Treatment Cross Hatch Field Test
Ammonium Zirconium 9.0 9.5
Carbonate + Polyacrylic Acid
Control - 0 0
EXAMPLE 12 `
2" X 4" galvanized steel panels were employed in
this procedure. The specimens were cleaned with an alkaline
cleaner at 170F for one minute and rinsed. Control panels
were cleaned with an alkaline cleaner, rinsed and dried.
Control panels were painted with a white acrylic paint~
Test panels were treated with an aqueous composition
comprising ammonium zirconium carbonate and polyacrylic acid -~
having a zirconium concentration of 1.0 gram/liter and a poly-
acrylic acid concentration of 1.0 gram/liter. The panels were
-36-
L~
1046872
then dried one minute at 400F and painted with the white
- acrylic paint.
Test panels and controls were subjected to the
water soak immersion test with 1% detergent solution and
then subjected to cross hatch and field testing. The results
are listed in Table 12 below.
Table 12
Treatment Cross Hatch Field Test
Ammonium Zirconium
Carbonate and Polyacrylic 10 10
Acid
Control 2 4
37-
. ~
