CA1047666A - Metal surface treating aqueous polymer zirconium compositions and process - Google Patents
Metal surface treating aqueous polymer zirconium compositions and processInfo
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- CA1047666A CA1047666A CA304,595A CA304595A CA1047666A CA 1047666 A CA1047666 A CA 1047666A CA 304595 A CA304595 A CA 304595A CA 1047666 A CA1047666 A CA 1047666A
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Abstract
ABSTRACT OF THE DISCLOSURE
An aqueous composition for treating a metal surface consisting essentially of from about 0.1 grams/liter to about 3.5 grams/liter of a soluble zirconium compound, measured as ZrO2, and from about 0.1 grams/liter to about 5.0 grams/liter of a polymeric material selected from the group consisting of polyacrylic acid, esters, and salts thereof, said composition having a pH from about 6.0 to about 8Ø Metal surfaces treated with such a composition exhibit improved bonding characteristics toward a siccative coating.
An aqueous composition for treating a metal surface consisting essentially of from about 0.1 grams/liter to about 3.5 grams/liter of a soluble zirconium compound, measured as ZrO2, and from about 0.1 grams/liter to about 5.0 grams/liter of a polymeric material selected from the group consisting of polyacrylic acid, esters, and salts thereof, said composition having a pH from about 6.0 to about 8Ø Metal surfaces treated with such a composition exhibit improved bonding characteristics toward a siccative coating.
Description
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In the art of treating metal surfaces, it is common practice to improve the corrosion resistance characteristics and paint bonding qualities of a me-tal 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 com-positions have been emplcyed. For example" compositions consisting essential-ly of aqueous acid phosphate or acid chromate solutions have been employed to treat bare metal surfaces already possessing a conversion coating to improve the 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 disclosed3 for example, in United States Patent Nos. 2,825,697; 2,678,291; 2,936,254; and 2,928,763.
An importar~t shortcoming, which treatments of the kind to which reference has been made possess, is the inherent toxicity and presence of a noxious materials in the effluents, such as hexaralent chromium, phosphates~
and fluorides. Waste disposal problems, handlir~ problems, and difficulties due to the corrosive action of the composition on the equipment employed are creat0d by the presence of acidic components in the bath effluent.
Another problem encountered with chromium containing treatments is that certain paint or lacquer systems will chip, peel, or blister when applied to a metal surface which has been treated with chromates. Worl~-pieces having complex configurations will accumulate residues of chromium ~ .
salts in areas such as crevices, pockets and joints. These areas will tend to display blistering, peeling, and generally in-ferior siccative finish 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 subsequent painting. Solutions and dispersions of this kind are disclosed, for example, in United States Patent Nos. 2,902,390; 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 associated with hexavalent chromium.
The primary object of the present invention is to provide a method for the treatment of metal surfaces which will enhance the corrosion resis-tance 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 enhances the adhesion properties of a subsequently applied siccative finish while eliminating the waste ~ -effluent disposal problems encountered with compositL~ms 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.
I have disco~Tered a chrome-free process and composition for treating the surfaces of metals such as iron, steel, zinc, altuninum and alloys in which they are the predolninant constituent. The aqueous composition employed 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.
It should be understood that the term "aqueous composikion" or ~aqueous solution" utilized herein means the aqueous a~ ture comprising zirconium, present as a soluble zirconitlm compound, and a polymeric material.
The concentration o zirconium present in -the aqueous composition, is expressed -- 2 --ra~ 6 herein as the concentration of ZrO2. This means that the zirconium, present as a soluble zireonium compound in solution, is in the 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 eomposition 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 dis-persion oE the polymer and zirconium eompound, as well as a solution of -the polymer and zirconium eompound. Examples of water soluble polymeric or resinous materials that can be utilized are polyacrylic acid, polyvinyl alcohol7 hydroxyethyl ethers of cellulose~ ethylene maleie anhydride, poly-vinyl pyrollidine, and polyvinyl methyl ether. An example of a polymeric material in the form of dispersed particles that can be utilized is an aerylic copolymer latice. Of course, the dispersed polymer or latex should be stable, in the presence of the other ingredients comprising the aqueous eomposition.
A wide variety of soluble zirconium compounds can be employed.
The selection of the eompound to be employed will depend on its eommercial a~ailability and its stability in solution with the polymeric material.
It is, of eourse, neeessary that upon its inelusion in the aqueous solution, it should not hydrolize to insoluble hydrous zireonium dioxide or an in-soluble ~ireonium salt at the operating p~l and temperature of the process, nor should it eause eoagulation of the polymeric material.
Typical examples of zireonium eompounds whieh ean be employed in the aqueous eomposition are alkali metal and ammonium fluozirconate and ammonium zireonium earbonate. The aqueous composition should comprise at least 0.1 grams/liter of the zirconium eompour~d (measured as ZrO2)- In the preferred embodiment, ammonium zireonium earbonate will be employed in the aqueous composition and its eoncentration, measured as ZrO2 will preferably 6~i6 be from about 0.1 grams/liter to about 3.5 grams/]iter.
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 this invention, the aqueous composition com-prises a water soluble polyacrylic acid. Water dispersible emulsions or latexes of polyacrylic acid derivatives are also commercially available, such as the alkali metal and ammonium salts of polyacrylic acid, and the poly-acrylic acid esters. By the term "acrylic acid polymer" or "polyacrylic acid", it should be understood that this means and applies to all -types of polymers to be utili~ed 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-1, Acrysol~A-3, and Acrysol~A-5. Water dispersible emul~
sions of polyacrylic acid esters are also available, for example those sold under the name Rhople~Ac-35~
The amount of polymer utilized can vary over a wide range. It is preferre~ that the polymeric material in the aqueous composition be present in an amount from about 0.1 grams/liter to about 5.0 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 surprising aspect of the present invention is that an aqueous composition having a concentration of polymeric material within the preferred range indicated above gives satisfactory uniform coatings which adhere to the sur~ace and improve the siccative finishing bondirlg characteristics of the surface. It is apparent that the amount of polymer present should be that amount which will be particularIy effective under the particular operating conditions of the treating process, so as to improve the corrosion resis-tallt capabilities and siccative finish bonding properties of the already formed coatir~, or in the case where no coating has been deposited, to improve the corrosion ~-Trade Mark - 4 -~ ,,.
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resistance of the bare metal surface and its paint bonding characteristics.
It has been found that the amount of polymeric material should preferably range from about ~.0 part to about 2.0 parts by weight for each part by weight of zirconium in the aqueous composition.
It 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 hereinbelow.
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 co~positions 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 be added directly to water in order to prepare the aqueous composition for use. It has been observed that, under certàin conditions, should an aqueous concentrate be prepared to make up the aqueous composition, hydrolysis and salting out of ~ "
both the zirconium compound and the polymer is evident. Of course, to prepare the composition each constituent is preferably added to the appro-priate amount of water to prepare a working bath having constituent con-centrations within the operative ranges set forth herein. ;
Preferably, the zirconium compound and polymer will evidence stability by remaining uniformly distributed throughout the aqueous phase of the composition, although in certain cases stirri~g of the composition may be employed to maintain a uniform dispersion during operation. In the preferred embodiment of the in~ention, the polymeric material should already be in solution or dispersed in the aqueous phase prior to the addition of the zirconium compound. This will ~urther insure against any hydrolysis ~ 5 ~4~
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 bondirg properties will result. In the preferred embodiment of this invention, with respect to the upper concentration limit of poly-acrylic acid, it has been found that no additional improvement over those obtained 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 lQ described herein, gives excellent and 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 coating 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 coatir~s or phosphate coatings. By chromate coatings, we mean those produced from aqueous baths con~aining hexavalent chromium, trivalent chromium, and/or salts thereof, as well as additional constituents such as phosphoric acid, 2Q and fluoride. By phosphate coatings, we mean those produced from aqueous solutions containing phosphoric acid and salts thereof, as well as additional constltuents such as fluorides, molybdates, chlorates, nitrites, and various organic accelerators.
Formula 1 is an example of a suitable dry chromate coating com-posi~ionwhich Gan be added to water to form a chroma~e coating solution which . .
can be employed to treat metal surfaces prior to their treatment with the aqueous composition:
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Formula 1 ~ by wei~h Chromic Acid 33-37 Potassium Fluo~irconate 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 be employed to treat aluminum surfaces forming a chromate-phosphat,e coating thereon, prior to the treatment with the aqueous composition.
Formula_2 % by weight Chromic Acid S7-60 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 em-ployed to treat metal surfaces prior to contact with the aqueous composition.
Formula 3 %~3Y~
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 subsequenk to treatment with a coating solution as described in Formula 3 hereinabove. A coati~g deposited by employing the coating solution prepared with Formula 3 on aluminum . .
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surfaces has the tendency to discolor, for instance after exposure toboiling water. Should coatings of this type be applied to aluminum container~
and then subjected to the conditions of pasteurization or pasteuri3ation procedures, such as immersion in boiling water at 250F~ an~ 15 psi, un-desirable discoloration will result. When the aqueous composition of the present invention is applied to aluminum surfaces having an underlying phosphate conversion coating of the kind formed from a solution of Formula 3, this discoloration can be prevented upon exposure of the surface to the temperature and pressure conditions described above.
Of course, the compositions of the present invention can be applied to a bare metal surface having no prior coating thereon. A sur-prising 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 saritar~y lacquer, such as an 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 constituents 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 sc~me proportions in which these con-stituents exist in the operating aqueous composition.
The preparation of the polymers suitable for use herein are wel~
known to the art. The acrylic acid polymer resins to be employecl in the preferred compositions of the present invention are prepared by means which can be considered solution-type polymeri~ation processes which result in a ,~, .....
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low molecular weight polymer. However, 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.
In the process of the present in~ention the metal substrate is brought into contact with the aqueous composition under suitable conditions 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 con~entional 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 com-; position need only be long enough to insure complete wetting of the surface and can be as long as 30 minutes. Preferably, contact time between 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 utili~ing a treating time of as little as one second.
` The coating process can be effected by employing ary of the con-tacting techniques known to the art. Contact can be effected by spray, immersion, or flow coating techniques. 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 in-fluenced by the ingredients comprising the composition, particularly the soluble irconium compound used. It has been found that best results are obtained when the operating pH of the composition is from about 6.0 to about _ g_ : ` ,:
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The process can be operated at a temperature from about 60F. to about 120F. It is preferred to operate the process at a temperature of from about 70F. to about 100F. Generally, a slight charge in the tempera-ture will not necessitate substantial alteration of the treating time, concentration parameters, or pM adjustment.
Following application of the aqueous composition, the surface can be subjected to a drying operation. The preferred range of temperatures for the drying operation is from about 60F. to about 500F. and, of course, the length o the dryirg step will depend upon the temperature utilized.
Once the drying step has been ef-fected, a siccative finish, such as a lacquer, can be applied to the surface with considerable aclhesion im- -provement. A-fter 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 present invention is that after contact with the aqueous composition has been accomplished~
the workpiece is resistant to corrosive attack, even when subjected to pro- ;longed exposure to air due to processing line stoppage prior to application of the siccative finish.
The following examples are illustrative of this invention and are not considered as limiting for other materials o~ operating conditions falling within the scope of the invention that might be substituted. Example 1 is set forth for the purposz of illustratir~ the preparation of an aqueous composition within the purview of this invent:ion. Examples 2 through 12 illustrate the improved results obtained employing the aqueous compositionO
In the examples~ certain comparative tests, defined hereinbelow, were effected on representative test specimens. Reverse impact tests were per~ormed to determine the adhesive characteristics of an organic or :
~76~i6 siccative coating applied to the surface. Ihis t~st 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 positioned with the painted side down and the unpainted surEace 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 pullir~ 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 sur~ace 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 deionized water or in a solution consistir~ of deionized water and 1% by volume of a liquid 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 milli-meter apart. Using the cross-hatch tool, one hundred squares measuring o~e millimeter by one millimeter are scribed on the painted surface. This is accomplished by drawing the scribing device across the area to be tested and then repeating the procedure by drawing the device across the same area but at a 90 argle to the first scribing. The cross-hatched area is su~b-jected to a tape adhesion 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 itsel~ wi-th a :
rapid pulling motion in a manner such that the tape is pulled from the surface o~ the specimen.
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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 im-pacted or cross-hatched. The tape is applied in a manner such that no air bubbles or wri~cles are present between the tape and the surface and 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 surfaee 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, em-ploying the rating system set forth hereinbelowO
The specimens were evaluated for paint loss or pain~ failure utiliz-ing 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-hatehed area and the "field test" area of the test specimens.
30 mls~ of an aerylie aeid polymer (Acrysol~'A-1, an aqueous solution eompr1sing polyacrylic aeid, manufaetured by Rohm and Haas) was added to 3 liters of water. 60 mls. of eommereially available ammonium zirconium car-bonate (an aqueous solution having a pH of about 8.5 marlceted by TAM, Division : . .
of National Lead Industries, Inc., and having 9% by weight of zircor um . .
therein (measured as ~rO2))was then added such that an aqueous composition comprising ammonium zireonyl earbonate and polyaerylic aeid having about 2 grams/liter of zireonium (measured as ZrO2) was formed. The pH of the solu-tion was measured at 7.2.
E~AMPLE 2 3 1/2" wide aluminum eoil stock was employed in this procedure.
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The aluminum eoil was put into 6" long test panels. The panels were cleaned ~Trade Mark - 12 -~ L76~6 with an alkaline cleaner at -160F. for 15 minutes and rinsed with water.
The test panels were then subjected to a conventional deoxidizing process and then subjected 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 was cleaned and deo~idized, and another set of;con*rol panels was cleaned, deoxidized, and contacted with the above chromate-phosphate solution.
Coated test panels were immersed in an aqueous composition consisting of polyacrylic acid and ammonium zirconium carbonate having a polyacrylic acid concentration of 2.7 grams/liter and a zirconium concentration of 1.8 grams/liter, 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 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 and "high temperature pressure weight loss~ test were performed on the control and test panels. In the high temperature-pressure test, the specime~s were placecl in a pressure ; vessel havir~ a glass liner therein and a carbonated beverage was poured therein. The vessels were sealçd and kept at 180F. 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 weight 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 . .
_ 13 -~71E;~;
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 char~e were noted. The results are listed in Table 1 hereinbelow.
Table t Average Weight Loss (m~/ft2) High Temp. - Pressure Test Room Te~p. Test 5 hr. Test 24 hr. Test (days) Treatment period perio_ 1 2 3 4 5 7 Controls-Cleaned and Deoxidized 9.4 16.2 20.9 32.4 36.4 36.4 36.4 36.0 -Controls-Cleaned, Deoxidized~
Chromate-Phosphate Coated 4.0 7.6 6.5 19.4 26.3 30.3 33.0 34.9 Test Panels- -Cleaned, Deoxidized, Chromate-Phosphate Coated Aqueous Composition 1.1 1.1 0.7 2.`2 5.8 6.1 7.2 7.2 Comprising Polyacrylic Acid and Ammonium Zirconium carbonate -~ It will be appreciated from the results in Table 1 that the test ; panels immersed in the aqueous composition gave superior and unexpected pro-tection over the Controls in terms of weight loss, when all test specimens were exposed to the corrosive effect of the beverage.
;~ E~AMPLE 3 ~` 3" wide aluminum can stock specimens were employed in this procedure.
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The specimens were cut into 6" long panels and cleaned in an acid cleaner at 170F. for one ~inute.
Four sets of control panels were i~nersed in four different 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 respec-':
' ~.0~76~
tively (measured ZrO2). Four sets of control panels were immersed in various ammonium zirconium carbonate solutions having concentrations of zirconium of 0.5 grams/liter; 1.0 gram/liter; l.S 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 speci-mens were utilized in four aqueous compositions having zirconium concentra-tions 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.
All 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-impact, cross-hatch, and ~Ifield~l tests, and the r:sults are li t-d in Table 2 below.
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Table 2 Reverse CrossField Treat ng Baths Impact HatchTest Zirconium Acetate Solution Zr2 Coneentration 0.5 g/l 0 0 0 1.0 g/l 0 2 0 1.5 g/l o 0 0
In the art of treating metal surfaces, it is common practice to improve the corrosion resistance characteristics and paint bonding qualities of a me-tal 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 com-positions have been emplcyed. For example" compositions consisting essential-ly of aqueous acid phosphate or acid chromate solutions have been employed to treat bare metal surfaces already possessing a conversion coating to improve the 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 disclosed3 for example, in United States Patent Nos. 2,825,697; 2,678,291; 2,936,254; and 2,928,763.
An importar~t shortcoming, which treatments of the kind to which reference has been made possess, is the inherent toxicity and presence of a noxious materials in the effluents, such as hexaralent chromium, phosphates~
and fluorides. Waste disposal problems, handlir~ problems, and difficulties due to the corrosive action of the composition on the equipment employed are creat0d by the presence of acidic components in the bath effluent.
Another problem encountered with chromium containing treatments is that certain paint or lacquer systems will chip, peel, or blister when applied to a metal surface which has been treated with chromates. Worl~-pieces having complex configurations will accumulate residues of chromium ~ .
salts in areas such as crevices, pockets and joints. These areas will tend to display blistering, peeling, and generally in-ferior siccative finish 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 subsequent painting. Solutions and dispersions of this kind are disclosed, for example, in United States Patent Nos. 2,902,390; 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 associated with hexavalent chromium.
The primary object of the present invention is to provide a method for the treatment of metal surfaces which will enhance the corrosion resis-tance 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 enhances the adhesion properties of a subsequently applied siccative finish while eliminating the waste ~ -effluent disposal problems encountered with compositL~ms 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.
I have disco~Tered a chrome-free process and composition for treating the surfaces of metals such as iron, steel, zinc, altuninum and alloys in which they are the predolninant constituent. The aqueous composition employed 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.
It should be understood that the term "aqueous composikion" or ~aqueous solution" utilized herein means the aqueous a~ ture comprising zirconium, present as a soluble zirconitlm compound, and a polymeric material.
The concentration o zirconium present in -the aqueous composition, is expressed -- 2 --ra~ 6 herein as the concentration of ZrO2. This means that the zirconium, present as a soluble zireonium compound in solution, is in the 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 eomposition 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 dis-persion oE the polymer and zirconium eompound, as well as a solution of -the polymer and zirconium eompound. Examples of water soluble polymeric or resinous materials that can be utilized are polyacrylic acid, polyvinyl alcohol7 hydroxyethyl ethers of cellulose~ ethylene maleie anhydride, poly-vinyl pyrollidine, and polyvinyl methyl ether. An example of a polymeric material in the form of dispersed particles that can be utilized is an aerylic copolymer latice. Of course, the dispersed polymer or latex should be stable, in the presence of the other ingredients comprising the aqueous eomposition.
A wide variety of soluble zirconium compounds can be employed.
The selection of the eompound to be employed will depend on its eommercial a~ailability and its stability in solution with the polymeric material.
It is, of eourse, neeessary that upon its inelusion in the aqueous solution, it should not hydrolize to insoluble hydrous zireonium dioxide or an in-soluble ~ireonium salt at the operating p~l and temperature of the process, nor should it eause eoagulation of the polymeric material.
Typical examples of zireonium eompounds whieh ean be employed in the aqueous eomposition are alkali metal and ammonium fluozirconate and ammonium zireonium earbonate. The aqueous composition should comprise at least 0.1 grams/liter of the zirconium eompour~d (measured as ZrO2)- In the preferred embodiment, ammonium zireonium earbonate will be employed in the aqueous composition and its eoncentration, measured as ZrO2 will preferably 6~i6 be from about 0.1 grams/liter to about 3.5 grams/]iter.
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 this invention, the aqueous composition com-prises a water soluble polyacrylic acid. Water dispersible emulsions or latexes of polyacrylic acid derivatives are also commercially available, such as the alkali metal and ammonium salts of polyacrylic acid, and the poly-acrylic acid esters. By the term "acrylic acid polymer" or "polyacrylic acid", it should be understood that this means and applies to all -types of polymers to be utili~ed 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-1, Acrysol~A-3, and Acrysol~A-5. Water dispersible emul~
sions of polyacrylic acid esters are also available, for example those sold under the name Rhople~Ac-35~
The amount of polymer utilized can vary over a wide range. It is preferre~ that the polymeric material in the aqueous composition be present in an amount from about 0.1 grams/liter to about 5.0 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 surprising aspect of the present invention is that an aqueous composition having a concentration of polymeric material within the preferred range indicated above gives satisfactory uniform coatings which adhere to the sur~ace and improve the siccative finishing bondirlg characteristics of the surface. It is apparent that the amount of polymer present should be that amount which will be particularIy effective under the particular operating conditions of the treating process, so as to improve the corrosion resis-tallt capabilities and siccative finish bonding properties of the already formed coatir~, or in the case where no coating has been deposited, to improve the corrosion ~-Trade Mark - 4 -~ ,,.
7~
resistance of the bare metal surface and its paint bonding characteristics.
It has been found that the amount of polymeric material should preferably range from about ~.0 part to about 2.0 parts by weight for each part by weight of zirconium in the aqueous composition.
It 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 hereinbelow.
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 co~positions 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 be added directly to water in order to prepare the aqueous composition for use. It has been observed that, under certàin conditions, should an aqueous concentrate be prepared to make up the aqueous composition, hydrolysis and salting out of ~ "
both the zirconium compound and the polymer is evident. Of course, to prepare the composition each constituent is preferably added to the appro-priate amount of water to prepare a working bath having constituent con-centrations within the operative ranges set forth herein. ;
Preferably, the zirconium compound and polymer will evidence stability by remaining uniformly distributed throughout the aqueous phase of the composition, although in certain cases stirri~g of the composition may be employed to maintain a uniform dispersion during operation. In the preferred embodiment of the in~ention, the polymeric material should already be in solution or dispersed in the aqueous phase prior to the addition of the zirconium compound. This will ~urther insure against any hydrolysis ~ 5 ~4~
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 bondirg properties will result. In the preferred embodiment of this invention, with respect to the upper concentration limit of poly-acrylic acid, it has been found that no additional improvement over those obtained 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 lQ described herein, gives excellent and 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 coating 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 coatir~s or phosphate coatings. By chromate coatings, we mean those produced from aqueous baths con~aining hexavalent chromium, trivalent chromium, and/or salts thereof, as well as additional constituents such as phosphoric acid, 2Q and fluoride. By phosphate coatings, we mean those produced from aqueous solutions containing phosphoric acid and salts thereof, as well as additional constltuents such as fluorides, molybdates, chlorates, nitrites, and various organic accelerators.
Formula 1 is an example of a suitable dry chromate coating com-posi~ionwhich Gan be added to water to form a chroma~e coating solution which . .
can be employed to treat metal surfaces prior to their treatment with the aqueous composition:
- 6 ~
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Formula 1 ~ by wei~h Chromic Acid 33-37 Potassium Fluo~irconate 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 be employed to treat aluminum surfaces forming a chromate-phosphat,e coating thereon, prior to the treatment with the aqueous composition.
Formula_2 % by weight Chromic Acid S7-60 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 em-ployed to treat metal surfaces prior to contact with the aqueous composition.
Formula 3 %~3Y~
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 subsequenk to treatment with a coating solution as described in Formula 3 hereinabove. A coati~g deposited by employing the coating solution prepared with Formula 3 on aluminum . .
~7~
surfaces has the tendency to discolor, for instance after exposure toboiling water. Should coatings of this type be applied to aluminum container~
and then subjected to the conditions of pasteurization or pasteuri3ation procedures, such as immersion in boiling water at 250F~ an~ 15 psi, un-desirable discoloration will result. When the aqueous composition of the present invention is applied to aluminum surfaces having an underlying phosphate conversion coating of the kind formed from a solution of Formula 3, this discoloration can be prevented upon exposure of the surface to the temperature and pressure conditions described above.
Of course, the compositions of the present invention can be applied to a bare metal surface having no prior coating thereon. A sur-prising 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 saritar~y lacquer, such as an 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 constituents 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 sc~me proportions in which these con-stituents exist in the operating aqueous composition.
The preparation of the polymers suitable for use herein are wel~
known to the art. The acrylic acid polymer resins to be employecl in the preferred compositions of the present invention are prepared by means which can be considered solution-type polymeri~ation processes which result in a ,~, .....
7~
low molecular weight polymer. However, 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.
In the process of the present in~ention the metal substrate is brought into contact with the aqueous composition under suitable conditions 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 con~entional 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 com-; position need only be long enough to insure complete wetting of the surface and can be as long as 30 minutes. Preferably, contact time between 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 utili~ing a treating time of as little as one second.
` The coating process can be effected by employing ary of the con-tacting techniques known to the art. Contact can be effected by spray, immersion, or flow coating techniques. 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 in-fluenced by the ingredients comprising the composition, particularly the soluble irconium compound used. It has been found that best results are obtained when the operating pH of the composition is from about 6.0 to about _ g_ : ` ,:
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The process can be operated at a temperature from about 60F. to about 120F. It is preferred to operate the process at a temperature of from about 70F. to about 100F. Generally, a slight charge in the tempera-ture will not necessitate substantial alteration of the treating time, concentration parameters, or pM adjustment.
Following application of the aqueous composition, the surface can be subjected to a drying operation. The preferred range of temperatures for the drying operation is from about 60F. to about 500F. and, of course, the length o the dryirg step will depend upon the temperature utilized.
Once the drying step has been ef-fected, a siccative finish, such as a lacquer, can be applied to the surface with considerable aclhesion im- -provement. A-fter 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 present invention is that after contact with the aqueous composition has been accomplished~
the workpiece is resistant to corrosive attack, even when subjected to pro- ;longed exposure to air due to processing line stoppage prior to application of the siccative finish.
The following examples are illustrative of this invention and are not considered as limiting for other materials o~ operating conditions falling within the scope of the invention that might be substituted. Example 1 is set forth for the purposz of illustratir~ the preparation of an aqueous composition within the purview of this invent:ion. Examples 2 through 12 illustrate the improved results obtained employing the aqueous compositionO
In the examples~ certain comparative tests, defined hereinbelow, were effected on representative test specimens. Reverse impact tests were per~ormed to determine the adhesive characteristics of an organic or :
~76~i6 siccative coating applied to the surface. Ihis t~st 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 positioned with the painted side down and the unpainted surEace 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 pullir~ 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 sur~ace 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 deionized water or in a solution consistir~ of deionized water and 1% by volume of a liquid 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 milli-meter apart. Using the cross-hatch tool, one hundred squares measuring o~e millimeter by one millimeter are scribed on the painted surface. This is accomplished by drawing the scribing device across the area to be tested and then repeating the procedure by drawing the device across the same area but at a 90 argle to the first scribing. The cross-hatched area is su~b-jected to a tape adhesion 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 itsel~ wi-th a :
rapid pulling motion in a manner such that the tape is pulled from the surface o~ the specimen.
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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 im-pacted or cross-hatched. The tape is applied in a manner such that no air bubbles or wri~cles are present between the tape and the surface and 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 surfaee 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, em-ploying the rating system set forth hereinbelowO
The specimens were evaluated for paint loss or pain~ failure utiliz-ing 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-hatehed area and the "field test" area of the test specimens.
30 mls~ of an aerylie aeid polymer (Acrysol~'A-1, an aqueous solution eompr1sing polyacrylic aeid, manufaetured by Rohm and Haas) was added to 3 liters of water. 60 mls. of eommereially available ammonium zirconium car-bonate (an aqueous solution having a pH of about 8.5 marlceted by TAM, Division : . .
of National Lead Industries, Inc., and having 9% by weight of zircor um . .
therein (measured as ~rO2))was then added such that an aqueous composition comprising ammonium zireonyl earbonate and polyaerylic aeid having about 2 grams/liter of zireonium (measured as ZrO2) was formed. The pH of the solu-tion was measured at 7.2.
E~AMPLE 2 3 1/2" wide aluminum eoil stock was employed in this procedure.
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The aluminum eoil was put into 6" long test panels. The panels were cleaned ~Trade Mark - 12 -~ L76~6 with an alkaline cleaner at -160F. for 15 minutes and rinsed with water.
The test panels were then subjected to a conventional deoxidizing process and then subjected 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 was cleaned and deo~idized, and another set of;con*rol panels was cleaned, deoxidized, and contacted with the above chromate-phosphate solution.
Coated test panels were immersed in an aqueous composition consisting of polyacrylic acid and ammonium zirconium carbonate having a polyacrylic acid concentration of 2.7 grams/liter and a zirconium concentration of 1.8 grams/liter, 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 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 and "high temperature pressure weight loss~ test were performed on the control and test panels. In the high temperature-pressure test, the specime~s were placecl in a pressure ; vessel havir~ a glass liner therein and a carbonated beverage was poured therein. The vessels were sealçd and kept at 180F. 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 weight 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 . .
_ 13 -~71E;~;
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 char~e were noted. The results are listed in Table 1 hereinbelow.
Table t Average Weight Loss (m~/ft2) High Temp. - Pressure Test Room Te~p. Test 5 hr. Test 24 hr. Test (days) Treatment period perio_ 1 2 3 4 5 7 Controls-Cleaned and Deoxidized 9.4 16.2 20.9 32.4 36.4 36.4 36.4 36.0 -Controls-Cleaned, Deoxidized~
Chromate-Phosphate Coated 4.0 7.6 6.5 19.4 26.3 30.3 33.0 34.9 Test Panels- -Cleaned, Deoxidized, Chromate-Phosphate Coated Aqueous Composition 1.1 1.1 0.7 2.`2 5.8 6.1 7.2 7.2 Comprising Polyacrylic Acid and Ammonium Zirconium carbonate -~ It will be appreciated from the results in Table 1 that the test ; panels immersed in the aqueous composition gave superior and unexpected pro-tection over the Controls in terms of weight loss, when all test specimens were exposed to the corrosive effect of the beverage.
;~ E~AMPLE 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 ~inute.
Four sets of control panels were i~nersed in four different 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 respec-':
' ~.0~76~
tively (measured ZrO2). Four sets of control panels were immersed in various ammonium zirconium carbonate solutions having concentrations of zirconium of 0.5 grams/liter; 1.0 gram/liter; l.S 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 speci-mens were utilized in four aqueous compositions having zirconium concentra-tions 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.
All 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-impact, cross-hatch, and ~Ifield~l tests, and the r:sults are li t-d in Table 2 below.
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Table 2 Reverse CrossField Treat ng Baths Impact HatchTest Zirconium Acetate Solution Zr2 Coneentration 0.5 g/l 0 0 0 1.0 g/l 0 2 0 1.5 g/l o 0 0
2.0 g/l 0 0 Ammonium Zirconium Carbonate Solution Zr2 Concentration 0.5 g/l 2 1 0 1.0 g/l 5 o 0 1.5 g/l 5 4 10 2.0 g/l 5 6 10 Ammonium ~irconyl Carbonate +
Polyaerylie Aeid 2 Concentration Polyaerylie Acid Coneentration :
0.5 g/l 0.7 g/l 7 9.5 10 1.0 g/l 1.4 g/l 8 9.5 10 1.5 g/l 2.1 g/l 9 9-0 10 2.0 g/l 2.8 g/l 7 10.0 10 It will be observed that the ammonium zireonyl earbonate and poly-I ' ' , .
acrylie aeid eomposition gave outstanding results in the tests as eompared to the eontrol specimens.
Aluminum can stoek was employed in this procedure. 3 ineh ~ 6 ineh panels were prepared from the ean stock. The speeimens, namely 4 sets of eontrol panels were treated in the zireonium aeetate solutions as in ~ Example 3~ 4 sets of eontrol panels were treated with the ammonil~n zirconyl .~
earbonate solutions as in Example 3, and 4 sets of test panels were immersed in aqueous eompositions eomprising ammonium zireonyl earbonate and poly-aerylie aeid therein and having the respective zirconium concentrations of 0.5 grams/liter; 1.0 gram /liter and 2.0 grams/liter (measured as ZrO2) and polyacrylic acid concentration of 0.7 grams/liter; 1.4 grams/liter; 2.1 grams/
liter and 208 grams/liter respectively. A ~inyl interior lacquer was applied to all panels and they were then subjected to a detergent immersion procedure and then reverse-impact, cross-hatch, and "~ield" testing. The results of the tests are listed in Table 3 belo~. ;
Table 3 Reverse CrossField Treating Baths Imp_ct HatchTest Zirconium Acetate Solution -- : .
Zr2 Concentrcation . . ~.
0.5 g/l 10 6 10 1.0 g/1 10 l 10 1.5 g/l 10 1 7 2.0 g/l 1~ 0 0 Ammonium Zirconium Carbonate Solution Zr2 Concentration 0.5 g/l 10 8 10 1.0 g/l 10 4 10 1.5 g/1 10 4 10 2.0 g/1 10 ~ 10 Ammonium Zireonium Carbonate Polyaeryl _ Acid Composition Zr2 Coneentration Polyaerylie Acid Concentration 0.5 g/1 0.7 g/1 10 2 ~0 - 1.0 g/1 1~4 g/1 10 6 10 1.5 g/1 2.1 g/l 10 9.8 10 2.0 g/l 2.8 g/l 10 10 10 .~
~ EXAMPLE 5 . _ .
Groups of aluminum test specimens were employed in this procedure.
~; 10 The eleaned test specimens comprised 3~ X 6~ panels. The panels were treated with a zirconîum acetate solution7 an ammonium zirconium carbor.c~te solution, and an aqueous eomposition eompris:ing ammonium zircorium carbonate and 6~
polyacrylie acid having the eoncentration parame-ters indicated in Table 4 below. The test panels were painted with an aerylie white paint and then were subjeeted to a deionized water immersion test at 180F. for 1/2 hour.
They were -then subjected to reverse-impaet, cross-hat;ch, and "field" testing.
The results are listed in Table 4 below.
Table 4 .
ReverseCross Field Treating Baths Impaet Hateh Test Zireo~ium Aeetate Solution Zr2 Coneentration ~ -.
0.5 g/l 7 8 8 t.0 g/l 3 0 0 1.5 g/l 5 1 0 2.0 g/l 5 Ammonium Zirconyl Carbonate Solution Zr2 Concentration 0~5 g/l 9.5 9.9 1 1.0 g/l 9.0 8.0 8 1.5 g/l 7.0 10.0 10 2.0 g/l 6.0 10.0 10 Ammonium Zireonyl Carbonate Polyacrylie Aeid Composition Zr2 Coneentration Polyacrylie Aeid Coneentration .
0.5 g/l 0.7 g/l 9.9 10 10 1.0 g/l 1.~ g/l 9-9 10 10 1.5 g/l 2.1 g/l 8.5 10 10 2.0 g/l 2.8 g/l 8.5 10 10
Polyaerylie Aeid 2 Concentration Polyaerylie Acid Coneentration :
0.5 g/l 0.7 g/l 7 9.5 10 1.0 g/l 1.4 g/l 8 9.5 10 1.5 g/l 2.1 g/l 9 9-0 10 2.0 g/l 2.8 g/l 7 10.0 10 It will be observed that the ammonium zireonyl earbonate and poly-I ' ' , .
acrylie aeid eomposition gave outstanding results in the tests as eompared to the eontrol specimens.
Aluminum can stoek was employed in this procedure. 3 ineh ~ 6 ineh panels were prepared from the ean stock. The speeimens, namely 4 sets of eontrol panels were treated in the zireonium aeetate solutions as in ~ Example 3~ 4 sets of eontrol panels were treated with the ammonil~n zirconyl .~
earbonate solutions as in Example 3, and 4 sets of test panels were immersed in aqueous eompositions eomprising ammonium zireonyl earbonate and poly-aerylie aeid therein and having the respective zirconium concentrations of 0.5 grams/liter; 1.0 gram /liter and 2.0 grams/liter (measured as ZrO2) and polyacrylic acid concentration of 0.7 grams/liter; 1.4 grams/liter; 2.1 grams/
liter and 208 grams/liter respectively. A ~inyl interior lacquer was applied to all panels and they were then subjected to a detergent immersion procedure and then reverse-impact, cross-hatch, and "~ield" testing. The results of the tests are listed in Table 3 belo~. ;
Table 3 Reverse CrossField Treating Baths Imp_ct HatchTest Zirconium Acetate Solution -- : .
Zr2 Concentrcation . . ~.
0.5 g/l 10 6 10 1.0 g/1 10 l 10 1.5 g/l 10 1 7 2.0 g/l 1~ 0 0 Ammonium Zirconium Carbonate Solution Zr2 Concentration 0.5 g/l 10 8 10 1.0 g/l 10 4 10 1.5 g/1 10 4 10 2.0 g/1 10 ~ 10 Ammonium Zireonium Carbonate Polyaeryl _ Acid Composition Zr2 Coneentration Polyaerylie Acid Concentration 0.5 g/1 0.7 g/1 10 2 ~0 - 1.0 g/1 1~4 g/1 10 6 10 1.5 g/1 2.1 g/l 10 9.8 10 2.0 g/l 2.8 g/l 10 10 10 .~
~ EXAMPLE 5 . _ .
Groups of aluminum test specimens were employed in this procedure.
~; 10 The eleaned test specimens comprised 3~ X 6~ panels. The panels were treated with a zirconîum acetate solution7 an ammonium zirconium carbor.c~te solution, and an aqueous eomposition eompris:ing ammonium zircorium carbonate and 6~
polyacrylie acid having the eoncentration parame-ters indicated in Table 4 below. The test panels were painted with an aerylie white paint and then were subjeeted to a deionized water immersion test at 180F. for 1/2 hour.
They were -then subjected to reverse-impaet, cross-hat;ch, and "field" testing.
The results are listed in Table 4 below.
Table 4 .
ReverseCross Field Treating Baths Impaet Hateh Test Zireo~ium Aeetate Solution Zr2 Coneentration ~ -.
0.5 g/l 7 8 8 t.0 g/l 3 0 0 1.5 g/l 5 1 0 2.0 g/l 5 Ammonium Zirconyl Carbonate Solution Zr2 Concentration 0~5 g/l 9.5 9.9 1 1.0 g/l 9.0 8.0 8 1.5 g/l 7.0 10.0 10 2.0 g/l 6.0 10.0 10 Ammonium Zireonyl Carbonate Polyacrylie Aeid Composition Zr2 Coneentration Polyacrylie Aeid Coneentration .
0.5 g/l 0.7 g/l 9.9 10 10 1.0 g/l 1.~ g/l 9-9 10 10 1.5 g/l 2.1 g/l 8.5 10 10 2.0 g/l 2.8 g/l 8.5 10 10
3~ ~ 6" aluminum ean stoek panels were used in this procedure. The - speeimens were cleaned with an alkaline cleaner at 160F. ~or 15 ~inutes.
They were then rinsed and deoxidized and then subjected to a phosphate pro-eessing sequence providing a phosphate conversion coating on the surface. The :
~ 76~6 phosphate coating solution of Formula 3 was applied to the test specimens.
Control panels were then painted with a white acrylic paint. The Control panels were then subjected to an immersion soak test with 1~ deter-gent solution and then subjected 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 con-centration of 1.0 grams/liter and 2.0 grams/liter respectively and a poly-acrylic acid concentration of 1.4 grams/liter and 2.8 grams/liter respecti~ely.
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 subjected to reverse-impact, cross-hatch, and field testing.
The results are listed in Table 5 below.
Table 5 ~ .
Reverse Cross Field Treatment Impact Hatch Test Phos~hate Coatin~ (Controls) O O O
Phosphate Coating -~
Zirconium Acetate Solution (Controls) Zr2 Concentration __ :
0.3 g/l 0 0 0 0.9 g/l 0 0 0 Phosphate Coating ~
Ammonium Zirconyl Carbonate Zr2 Concentration Polyacrylic Acid Concentration 1.0 g/l 1.4 g/l 10.0 8 10 2.0 ~ 1 2.8 ~1 9 5 6 10 - 19- . .
~L76~ -~PLE 7 In this procedure aluminum test panels 3" X 6" were emp1Oyed. 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) polyacrylic acid; b) ammonium zirconium carbonate; c) ammonium fluozirconate;
d) aqueous composition comprising polyacrylic acid and ammonium zirconium carbonate; and e) an aqueous composition comprising polyacrylic acid and ammonium fluozirconate. The panels were then dried at ambient temperature.
The concentrations of the particular constituents în the respective treating compositions is 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.
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Table 6 Adhesion Result_ Reverse Cross Field Compositions Impact Ha-tch Test A) 1) 0.7 g/l Polyacrylic Acid 8 9.5 9.S
2) 2.1 g/l Polyacrylic Acid 9.5 1.0 7.0 B) Ammoni~ Zirconyl Carbonate 1) 0.5 g/l Zirconium 8.0 10.0 10.0 2) 1.5 g/l Zirconium 5.0 9.0 10.0 ;
C) Ammonium Fluozirconate 1) 0.5 g/l Zirconium 8.0 0 7.0 2) 1.5 g/l Zirconium 6.0 10.0 10.0 D) Polyacrylic Acid and Ammonium Zirconyl Ca~rbonate 1) 0.7 g/l Polyacrylic Acid and 0.5 g/l Zirconium 10.0 10.0 10.0 2) 2.1 g/l Polyacrylic Acid and 1.5 g/l Zirconium 10.0 10.0 10.0 `~
E) Polyacrylic Acid and Ammonium Fluozirconate 1) 0.7 g/l Polyacrylic Acid and 0.5 g/l Zirconium 10.0 10.0 10.0 2) 2.1 g/l Polyacrylic Acid and 1.5 g/l Zirconium 9.8 10.0 10.0 F) Control 1) Cleaned and Painted 4.0 0 0 ~ -EXA~PLE 8 3 inch X 4 inch aluminum test panels were employed in this procedure.
The panels were cleaned with an alkaline cleaner at 180Fo for one minute.
They were rinsed with water arld groups o~ the test panels were subjected to ,;
various phosphate processing sequences providing phosphate col~verslon coatings on their surfaces. The phosphate coating solutions employed on the groups of test panels were as follows: ;
- 21 - ;~
- . - . .. ... ~ : .
76~
75%
Phosphoric Ammonium Sodium Test Acid Bifluoride Molybdate Runs a 9.8 1.14 0.1b 1.2 0.29 0.1c 3.5 0.57 0.1d 7.0 0.86 0.1e 102 0029 0.1f 3.5 0.29 0.1After 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.
The painted panels were then subjected to the following tests:
a) Immersion in water at 150F. for 30 minutes and then subjected to the cross-hatch test. ~-b) Immersion 1n a 1% detergent solution at 180F. for 30 minutes and then subjected to the cross-hatch test.
The table below lists the results of the tests. The specimens , ~ were qualitatively evaluated for paint loss. The ratings appearing inTable 7 below are as follows~ ) representing no paint loss, (0) represent-ing a slight or moderate paint loss~ and (-~ representing heavy or total pa1nt loss.
.
76&~
Table 7 Zirconium Polyacrylic Acid I De:Lonized Water 1% 1 1%
TestWater Detergent IWater Detergent RunsImmersionImmersion !Immersion Immersion a + 0 ¦ - -b +
c + ~ I _ _ d + -~ ¦ +
e + ~ 1 + 0 f ~ - I - - ;
E~AMPLE 9 2~' X 4" tin plated steel panels were used in this procedure. The specimens were cleaned with an alkaline cleaner at 170F. for one minute and rinsed. Control panels were cleaned with the alkaline cleaner, rinsed and dried. Control panels were painted with a white acrylic paint. Two sets of test panels were treated with two separate aqueous compositions com-prising 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 0O7 grams/liter ar.d 2.1 grams/liter res~
pectively. The test panels were dried for one minute at 400F. and then painted with the white acrylic paint. Test panels~ and Controls were then subjected to the water soak immersion test with detergent and then subjected o cross-hatch and fiel1 testmg, The results are listed ir~ Table 8 below.
:: '' : ' ", ~ "
5$~
Table 8 Cross Field Treatment Hatch Test Controls 0 2 Ammonium Zirconyl Carbonate and_Polyacrylic Acid Zr2 Concentration Polyacrylic Acid _ Concentration 0.5 g/l 0.7 g/l 10 9 1.5 g/l 2.1 g/l 10 9 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 Control 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 15 seconds at room temperature. The test panels were then dried at 400 F. for one minute and painted with a white acrylic paint. The con-centrations of the-particular constituents in the respective aqueous com-positions listed in Table 9 were 2.0 grams/liter of ammonium zirconium car-bonate and 2.0 grams/liter of the polymeric material.
Thereafter the control and test panels were subjected to an immer-sion test in boiling water for 30 minutes. All panels ~ere 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 Material _ _ Impact Hatch Test Controls Polyacrylic Acid, (Acryso~'A-1, Rohm ~ Haas) 10 10 10 Polyacrylic Acid, (Acrysol~A-3, Rohm ~ Haas) 10 lO 10 Polyacrylic Acid, (Acrysol~A-5, Rohm ~ Haas) 10 10 10 Polyacrylic Acid, (Goodrite~-K3~, Goodrich) 10 10 10 Polyacrylic Acid, (Goodrite~K702, Goodrich) 9 2 6 Carboxy vinyl polymer, (Carbapol~-801, Goodrich) 10 10 10 Acrylic copolymer dispersion, (Acrysol W24 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, (Rhople~MV-1~ Rohm ~ Haas) 5 10 9 `
Acrylic hydrosol emulsion, (Elvacet~'9012, . ~, ,.
Additional test panels were immersed in aqueous compositions com- ~
prising ammonium zirconium carbonate and a 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 zir-conium 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 ~ 10 results are listed in Table 10 below.
.` ;
.. .
~Trade Mark - 25 -~ .
Table 10 Ammonium Zirconium Carbonate ~ Reverse Cross Field Polymeric Material _ Im;~ Hatch Test Control 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, (Gantre~'M154, GAF) 3 10 12 Polyvinyl Pyrollidone, (NP-K30, GAF) 1 0 1 Phosphated Starch, {ARD 1230, American Maize)9.9 10 10 Hydroxy methyl cellulose, (WP-40, Union Carbide) 10 10 10 2" X 4" steel panels were used in this procedure. The panels were cleaned with an alkaline cleaner at 170F. for one minute and rinsed.
Control panels were dried and 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 poly-acrylic acid having a zirconium concentration of 1.0 gram/liter (measured as ZrO2) and a polyacrylic acid concentration of 1.0 gram/liter. The panels were then dried one 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 subjected to cross-hatch and field testir~. The result- are 1isted in Table tl below.
*Trade Mark - 26 -6~
Table il Cross Field Treatment Hatch Test Ammonium Zirconium Carbonate + Polyacrylic 9.0 9.5 Acid Control 0 0 2l' X 4" gal~anized 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 aqweous compcsition comprising ammonium ~irconiwm carbonate and polyacrylic acid having a zirconium con-centration o~ 1.0 gram/liter and a polyacrylic acid concentration of 1.0 gram/liter. The panels were 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 testingO The results are listed in Table 12 below.
Table 12 Cross Field Treatment Hatch Test -Ammor~wm ~irconiwm Carbonate and Polyacrylic 10 10 Acid Control 2 4 ' ~ .
.. .,.. ,-. .... ,... j , ... -. ~. . ... .
They were then rinsed and deoxidized and then subjected to a phosphate pro-eessing sequence providing a phosphate conversion coating on the surface. The :
~ 76~6 phosphate coating solution of Formula 3 was applied to the test specimens.
Control panels were then painted with a white acrylic paint. The Control panels were then subjected to an immersion soak test with 1~ deter-gent solution and then subjected 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 con-centration of 1.0 grams/liter and 2.0 grams/liter respectively and a poly-acrylic acid concentration of 1.4 grams/liter and 2.8 grams/liter respecti~ely.
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 subjected to reverse-impact, cross-hatch, and field testing.
The results are listed in Table 5 below.
Table 5 ~ .
Reverse Cross Field Treatment Impact Hatch Test Phos~hate Coatin~ (Controls) O O O
Phosphate Coating -~
Zirconium Acetate Solution (Controls) Zr2 Concentration __ :
0.3 g/l 0 0 0 0.9 g/l 0 0 0 Phosphate Coating ~
Ammonium Zirconyl Carbonate Zr2 Concentration Polyacrylic Acid Concentration 1.0 g/l 1.4 g/l 10.0 8 10 2.0 ~ 1 2.8 ~1 9 5 6 10 - 19- . .
~L76~ -~PLE 7 In this procedure aluminum test panels 3" X 6" were emp1Oyed. 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) polyacrylic acid; b) ammonium zirconium carbonate; c) ammonium fluozirconate;
d) aqueous composition comprising polyacrylic acid and ammonium zirconium carbonate; and e) an aqueous composition comprising polyacrylic acid and ammonium fluozirconate. The panels were then dried at ambient temperature.
The concentrations of the particular constituents în the respective treating compositions is 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.
`.
: , :
, ' . ~ ' ' ' ~
:~
' . :
66~
Table 6 Adhesion Result_ Reverse Cross Field Compositions Impact Ha-tch Test A) 1) 0.7 g/l Polyacrylic Acid 8 9.5 9.S
2) 2.1 g/l Polyacrylic Acid 9.5 1.0 7.0 B) Ammoni~ Zirconyl Carbonate 1) 0.5 g/l Zirconium 8.0 10.0 10.0 2) 1.5 g/l Zirconium 5.0 9.0 10.0 ;
C) Ammonium Fluozirconate 1) 0.5 g/l Zirconium 8.0 0 7.0 2) 1.5 g/l Zirconium 6.0 10.0 10.0 D) Polyacrylic Acid and Ammonium Zirconyl Ca~rbonate 1) 0.7 g/l Polyacrylic Acid and 0.5 g/l Zirconium 10.0 10.0 10.0 2) 2.1 g/l Polyacrylic Acid and 1.5 g/l Zirconium 10.0 10.0 10.0 `~
E) Polyacrylic Acid and Ammonium Fluozirconate 1) 0.7 g/l Polyacrylic Acid and 0.5 g/l Zirconium 10.0 10.0 10.0 2) 2.1 g/l Polyacrylic Acid and 1.5 g/l Zirconium 9.8 10.0 10.0 F) Control 1) Cleaned and Painted 4.0 0 0 ~ -EXA~PLE 8 3 inch X 4 inch aluminum test panels were employed in this procedure.
The panels were cleaned with an alkaline cleaner at 180Fo for one minute.
They were rinsed with water arld groups o~ the test panels were subjected to ,;
various phosphate processing sequences providing phosphate col~verslon coatings on their surfaces. The phosphate coating solutions employed on the groups of test panels were as follows: ;
- 21 - ;~
- . - . .. ... ~ : .
76~
75%
Phosphoric Ammonium Sodium Test Acid Bifluoride Molybdate Runs a 9.8 1.14 0.1b 1.2 0.29 0.1c 3.5 0.57 0.1d 7.0 0.86 0.1e 102 0029 0.1f 3.5 0.29 0.1After 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.
The painted panels were then subjected to the following tests:
a) Immersion in water at 150F. for 30 minutes and then subjected to the cross-hatch test. ~-b) Immersion 1n a 1% detergent solution at 180F. for 30 minutes and then subjected to the cross-hatch test.
The table below lists the results of the tests. The specimens , ~ were qualitatively evaluated for paint loss. The ratings appearing inTable 7 below are as follows~ ) representing no paint loss, (0) represent-ing a slight or moderate paint loss~ and (-~ representing heavy or total pa1nt loss.
.
76&~
Table 7 Zirconium Polyacrylic Acid I De:Lonized Water 1% 1 1%
TestWater Detergent IWater Detergent RunsImmersionImmersion !Immersion Immersion a + 0 ¦ - -b +
c + ~ I _ _ d + -~ ¦ +
e + ~ 1 + 0 f ~ - I - - ;
E~AMPLE 9 2~' X 4" tin plated steel panels were used in this procedure. The specimens were cleaned with an alkaline cleaner at 170F. for one minute and rinsed. Control panels were cleaned with the alkaline cleaner, rinsed and dried. Control panels were painted with a white acrylic paint. Two sets of test panels were treated with two separate aqueous compositions com-prising 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 0O7 grams/liter ar.d 2.1 grams/liter res~
pectively. The test panels were dried for one minute at 400F. and then painted with the white acrylic paint. Test panels~ and Controls were then subjected to the water soak immersion test with detergent and then subjected o cross-hatch and fiel1 testmg, The results are listed ir~ Table 8 below.
:: '' : ' ", ~ "
5$~
Table 8 Cross Field Treatment Hatch Test Controls 0 2 Ammonium Zirconyl Carbonate and_Polyacrylic Acid Zr2 Concentration Polyacrylic Acid _ Concentration 0.5 g/l 0.7 g/l 10 9 1.5 g/l 2.1 g/l 10 9 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 Control 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 15 seconds at room temperature. The test panels were then dried at 400 F. for one minute and painted with a white acrylic paint. The con-centrations of the-particular constituents in the respective aqueous com-positions listed in Table 9 were 2.0 grams/liter of ammonium zirconium car-bonate and 2.0 grams/liter of the polymeric material.
Thereafter the control and test panels were subjected to an immer-sion test in boiling water for 30 minutes. All panels ~ere 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 Material _ _ Impact Hatch Test Controls Polyacrylic Acid, (Acryso~'A-1, Rohm ~ Haas) 10 10 10 Polyacrylic Acid, (Acrysol~A-3, Rohm ~ Haas) 10 lO 10 Polyacrylic Acid, (Acrysol~A-5, Rohm ~ Haas) 10 10 10 Polyacrylic Acid, (Goodrite~-K3~, Goodrich) 10 10 10 Polyacrylic Acid, (Goodrite~K702, Goodrich) 9 2 6 Carboxy vinyl polymer, (Carbapol~-801, Goodrich) 10 10 10 Acrylic copolymer dispersion, (Acrysol W24 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, (Rhople~MV-1~ Rohm ~ Haas) 5 10 9 `
Acrylic hydrosol emulsion, (Elvacet~'9012, . ~, ,.
Additional test panels were immersed in aqueous compositions com- ~
prising ammonium zirconium carbonate and a 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 zir-conium 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 ~ 10 results are listed in Table 10 below.
.` ;
.. .
~Trade Mark - 25 -~ .
Table 10 Ammonium Zirconium Carbonate ~ Reverse Cross Field Polymeric Material _ Im;~ Hatch Test Control 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, (Gantre~'M154, GAF) 3 10 12 Polyvinyl Pyrollidone, (NP-K30, GAF) 1 0 1 Phosphated Starch, {ARD 1230, American Maize)9.9 10 10 Hydroxy methyl cellulose, (WP-40, Union Carbide) 10 10 10 2" X 4" steel panels were used in this procedure. The panels were cleaned with an alkaline cleaner at 170F. for one minute and rinsed.
Control panels were dried and 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 poly-acrylic acid having a zirconium concentration of 1.0 gram/liter (measured as ZrO2) and a polyacrylic acid concentration of 1.0 gram/liter. The panels were then dried one 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 subjected to cross-hatch and field testir~. The result- are 1isted in Table tl below.
*Trade Mark - 26 -6~
Table il Cross Field Treatment Hatch Test Ammonium Zirconium Carbonate + Polyacrylic 9.0 9.5 Acid Control 0 0 2l' X 4" gal~anized 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 aqweous compcsition comprising ammonium ~irconiwm carbonate and polyacrylic acid having a zirconium con-centration o~ 1.0 gram/liter and a polyacrylic acid concentration of 1.0 gram/liter. The panels were 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 testingO The results are listed in Table 12 below.
Table 12 Cross Field Treatment Hatch Test -Ammor~wm ~irconiwm Carbonate and Polyacrylic 10 10 Acid Control 2 4 ' ~ .
.. .,.. ,-. .... ,... j , ... -. ~. . ... .
Claims
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An aqueous composition for treating a metal surface consisting essentially of from about 0.1 grams/liter to about 3.5 grams/liter of a soluble zirconium compound, measured as ZrO2, and from about 0.1 grams/liter to about 5.0 grams/liter of a polymeric material selected from the group consisting of polyacrylic acid, esters, and salts thereof, said composition having a pH from about 6.0 to about 8Ø
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US379138A US3912548A (en) | 1973-07-13 | 1973-07-13 | Method for treating metal surfaces with compositions comprising zirconium and a polymer |
| CA203,178A CA1046872A (en) | 1973-07-13 | 1974-06-24 | Metal surface treating aqueous polymer zirconium composition and process |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1047666A true CA1047666A (en) | 1979-01-30 |
Family
ID=25667607
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA304,595A Expired CA1047666A (en) | 1973-07-13 | 1978-06-01 | Metal surface treating aqueous polymer zirconium compositions and process |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1047666A (en) |
-
1978
- 1978-06-01 CA CA304,595A patent/CA1047666A/en not_active Expired
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