CA2130886A1 - Composition and process for treating metal surfaces - Google Patents
Composition and process for treating metal surfacesInfo
- Publication number
- CA2130886A1 CA2130886A1 CA002130886A CA2130886A CA2130886A1 CA 2130886 A1 CA2130886 A1 CA 2130886A1 CA 002130886 A CA002130886 A CA 002130886A CA 2130886 A CA2130886 A CA 2130886A CA 2130886 A1 CA2130886 A1 CA 2130886A1
- Authority
- CA
- Canada
- Prior art keywords
- silicate
- plus
- aqueous solution
- condensation product
- cationic polymer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
- C23C22/60—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using alkaline aqueous solutions with pH greater than 8
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D183/00—Coating compositions based on macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon, with or without sulfur, nitrogen, oxygen, or carbon only; Coating compositions based on derivatives of such polymers
- C09D183/02—Polysilicates
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D183/00—Coating compositions based on macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon, with or without sulfur, nitrogen, oxygen, or carbon only; Coating compositions based on derivatives of such polymers
- C09D183/04—Polysiloxanes
- C09D183/08—Polysiloxanes containing silicon bound to organic groups containing atoms other than carbon, hydrogen, and oxygen
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C2222/00—Aspects relating to chemical surface treatment of metallic material by reaction of the surface with a reactive medium
- C23C2222/20—Use of solutions containing silanes
Abstract
ABSTRACT
A non-chromate conversion coating for metal surfaces such as aluminum, steel, galvanized steel and zinc-aluminum steel consisting of an aqueous solution of a cationic polymer, an alkaline aqueous silicate and an organofunctional silane.
A non-chromate conversion coating for metal surfaces such as aluminum, steel, galvanized steel and zinc-aluminum steel consisting of an aqueous solution of a cationic polymer, an alkaline aqueous silicate and an organofunctional silane.
Description
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COMPOSITION AND PROCESS FOR TREATING METAL SURFACES
FIELD OF THE INVENTION
The present invention relates to the process of coating metals to improve the corrosion resistance and adhesion properties of the metal's surface. Specifically, the present invention relates to a single non-chromium treatment that is . ;~
equally effective on many different metal surfaces. Such metals include aluminum, steel, zinc coated steel and zinc-aluminum ;~
coated steel.
BACKGROUND OF THE INVENTION
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The purpose of conversion coatings on metal surfaces are ~ ;
to provide corrosion resistance and improve the adhesion of the ultimate coating(s). The conversion coating improves the adhesion of final coating layers such as paints, inks, lacquers and plastics.
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COMPOSITION AND PROCESS FOR TREATING METAL SURFACES
FIELD OF THE INVENTION
The present invention relates to the process of coating metals to improve the corrosion resistance and adhesion properties of the metal's surface. Specifically, the present invention relates to a single non-chromium treatment that is . ;~
equally effective on many different metal surfaces. Such metals include aluminum, steel, zinc coated steel and zinc-aluminum ;~
coated steel.
BACKGROUND OF THE INVENTION
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The purpose of conversion coatings on metal surfaces are ~ ;
to provide corrosion resistance and improve the adhesion of the ultimate coating(s). The conversion coating improves the adhesion of final coating layers such as paints, inks, lacquers and plastics.
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"'`~ ~ ' '' '''i"'' Traditionally, chromates have been utilized as conversion coating compounds. Chromates are known to exhibit acceptable performance on different types of metals or alloys, such as aluminum, steel, galvanized steel and zinc-aluminum coated steel. Chromate conversion coatings are typically administered `~"~''',~:''`,`'7' by contacting the metal surface with an aqueous solution containing hexavalent or trivalent chromium ions, phosphate ions ;~
or fluoride ions. Serious concerns have been raised, however, regarding the pollution effects of the chromate or phosphate ~ 'G'-'~
discharged into rivers or waterways by such processes. Due to the high solubility and the strongly oxidizing character of `~
hexavalent chromium ions, conventional chromate conversion coating processes require extensive waste treatment procedures to control their discharge.
While many acceptable chromium-free conversion coatings ~ y have been developed, their utility is often limited to only one ~: ~
type of metal substrate. Many industrial operations, however, involve the sequentlal processing of different types of metals. ''~.,,n~`'","`''~
Unless the undesirable chromium compounds are used, the industrial metal processor is forced to change the conversion coating bath for each different type of metal. This results in unacceptable downtime and higher processing costs.
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3_ It is desirable, therefore, to have a conversion coating compound which is equally effective on more than one type of metal. This is achieved by the composition and process of the ~n present invention. - -SUMMARY OF THE INVENTION
The present inventors have discovered a metal conversion coating which enhances the corrosion resistance and the adhesion properties of the surface of the metal. It provides excellent paint adhesion and corrosion resistance. The coating of the present invention is formed from an aqueous solution containing an alkaline aqueous silicate, a cationic agent and, optionally, ~ `
an organofunctional silane. `~
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT ' "`
The present inventors have discovered an effective method -of pre-treating metal surfaces by first applying to the surface an aqueous solution of a cationic agent and an alkaline aqueous silicate followed, if desired or needed, by an aqueous organofunctional silane solution. Alternatively, all materials ~ r,~
may be combined into a single solution and applied to the target metal surface in a single application.
The unique feature of the conversion coating composition of the present invention is that it forms an effective coating on the surfaces of metals such as aluminum, steel, zinc coated steel (galvanized) and zinc-aluminum coated steel (Galvalume~
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2 l 3 o 8 8 ,.. ;~..~' ,' The alkaline silicates used in this invention are derived from either ortho- or condensed silicates. Water soluble salts of the following inorganic anions, in particular the sodium, potassium and ammonium salts thereof, may be used in the practice of this invention. Such compounds are~
Metasilicate - sio32-Orthosilicate - sio44~
Disilicate - Si205-2 .
Mixed Silicates - Na20 xSiO2(where x=1-5) :
Aluminosilicates - Na20 xA1203 ySiO2 (where x+y=3-5) The preferred inorganic silicates are alkaline di- and meta-silicates where the ratio of SiO2 to Na20 is from about 2 to 1 to about 1 to 1. ~ h~`
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The cationic agents of the present invention are cationic -~
polymers which are of low to medium molecular weight, have a high .. ,~
charge density and may be cross-linked or linear condensation or ~--,? addition polymers. Their number average molecular weight ranges ".. .
be~ween 1,000 and 600,00C and they are water soluble The charge densities, as determined by the PVSK Colloid Titration Method (H. ~, Terayama, Kayaku no Kenkya, Vol. 1, p. 75, 1948; H. Terayama, -~
Kayaku no Kenkya, Vol. 4, p. 31, 1949; R. Senju, "Koroido ~ ".,~ ;-Tekiteiho", Nankodo, Tokyo, 1969), are active in the range of . ,~
about 1.5 to 12.0 meq/g active polymer.
Those polymers, which have demonstrated the desired performance characteristics, are: ~-: ~:
,,, . -~
PolYmer Descr~ption I polydiallyl dimethyl ammonium chloride (avallable from CPS Chemical as Age Flex) ~ ;~
II condensat;on product of dimethylamine plus epichlorohydrin plus ethylenediamine (avaif;ble from American Cyanamid as I I I condensation product of dimethylamine plus epichlorohydrin (U.S. Patent No. 3,738,945 IV condensation product of diethylenetriamine plus adipic acid plus epichlorohydrin (Betz ~ .
Laboratories, Inc., Polymer 1175) V condensation product of hexamethylenediamine st~ll bottoms plus ethylene dichloride plus epichlorohydrin tavailable from Monsanto as :~
2 1 3 ~ ~ ~ fi The organofunctional silanes are hydrolyzed and are --~
prepared from the respective alkoxysilanes where one or more alkoxide groups are converted to a silanol tSi-OH, or Si-0-) function through acid or base hydrolysis. These may be prepared 5 from a wide variety of organofunctional alkoxysilanes. The ;
techniques are familiar to those practiced in the art and are readily available in the literature. See, for example, E.P.
Pluddemann, "Silane Coupling Agents", 2nd. ed., Plenum Press, 1991, chapter 2, herein incorporated by reference.
The organofunctional silanes which exhibit the desired utility in this invention are aminosilanes. The preferable aminosilane is a hydrolyzed aminopropyltrimethoxysilane. This compound is commercially available as an approximately 20% active aqueous solution from Huls America and is designated as Hydrosil 2627. `"~
The alkaline silicate and cationic polymer may be applied ~ ~
either as a single aqueous solution, or in sequence with or with- ;~ v out an intervening rinse step, depending on the solubilities of the materials. Concentrations are from about .01 to about .07 molar of the alkaline silicate. For the cationic polymers, a weight ratio of about from 10 to about 700 grams of polymer solids per mole of silicate is utilized. For the organofunctional ;~
silaoe, a weight ratio of about 5 to aboot 250 grams of 21 3 D ~
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organosilane solids per mole of silicate is utilized. A preferred pretreatment process comprises a solution which contains from 0.01 i=
to 0.02 molar alkaline silicate with from 1.0 to 1.3 g/l of cat- `~;~ q-;~, ionic polymer solids. This is followed by an optional water rinse ~`~
and then application of a solution of 10 to 13 g/l of the organo-functional silane.
The treatment solution(s) may be applied to the metal -~
surface to be treated by any conventional means such as spraying, wetting by dip squeegee, flow coating, roll coating and the like.
Roll coating is generally preferred. The final solution of the present invention is preferably dried in place.
The following illustrative scheme summarizes the several possible sequences of application contemplated in this invention. ~ ~ ;
In the scheme, "+" denotes that the agents are combined in solution, "/" denotes a separate solution or stage and "*" denotes that the step may be omitted.
alkaline silicate/rinse*/cationic polymer/rinse*/organo-functional silane alkaline silicated + cationic polymer/rinse*/organo-functional silane alkaline silicate + cationic polymer + organofunctional -~
silane.
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EXAMPLES -The present invention will now be further described with -reference to a number of specific examp1es which are to be - ~ ~
regarded solely as illustrative and not as restricting the scope ",''"'~'!'' of the present invention.
Example 1 -The following test procedure was followed. Hot dipped galvanized steel panels were obtained from ACT Corp. They were ~:
spray cleaned with a hot alkaline surfactant solution in water, rinsed, passed through squeegee rolls to remove most of the water, ;~
and then spin-coated by flooding the panel surface with the solutions below. The wet panels were spun for 10 sec. after the solution was applied. The panels were dried in place on the spinner with a stream of hot air. - ~-n~
Comparative pretreatment solutions are as follows:
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A. 15% Betz Permatreat 1006, a non-Cr pretreatment for galvanized steel containing dihydrofluorozirconic acid and an acrylic acid copolymer.
B. 11% Betz Permatreat 1500, a mixed ~ -hexavalent-trivalent chromium pretreatment , ~ containing silicon dioxide.
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2 ~ 3 0 8 ~ 6 C. 15% Betz Permatreat 1500.
D. 1.2% solution of the product of Example 13 ~-of W0 85/05131 (utilizes a chromate based final rinse).
The panels were painted with a two-coat epoxy/fluorocarbon paint system specified for galvanized steel, and cured in accordance with the manufacturer's specifications.
The adhesion and corrosion performance of the treated and painted galvanized steel were evaluated using a Wedge Bend test and a 500 hour Neutral Salt Spray test, respectively. In the Wedge Bend test, a tapered 180 degree bend in the metal is formed by first turning it to a radius of about 0.5 cm and then flatten-ing the metal to a near zero radius. The stressed surface is then subjected to a tape pull, and the amount of paint loss (in mm) is recorded. 0 mm is perfect. Neutral Salt Spray (NSS) tests were carried out in accordance with ASTM B-117, with the scribe and rating methods following ASTM D-1654 Test Method B, Procedure A
7.2. The ratings are from 0 to 10 (10 = perfect).
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In some cases, a condensing humidity test was employed.
This test followed the protocol of National Coil Coaters' Association Technical Bulletin No. III-3 and III-6. Blistering is rated on a scale of 0 to 10 (10=perfect). -~
The response of adhesion and corrosion performance from the sequential application of the silicate and the cationic polymer will be appreciated from the following table~
TABLE I
Silicate Polymer Wedge Bend 500 hr NSS Average `~
(molar) PolYmer q/l solids mm loss Scribe Ratina .0125 0 26 5.5 .0125 III 0.25 23 6.0 .0125 III 1.0 13 5.8 O III 1.0 44 5.2 .0125 II 0.31 26 5.0 .0125 II 1.25 0 6.5 ;:
O II 1.25 31 5.8 Comparative Pretreatment A: 11 5.5 Comparative Pretreatment B: 0 6.5 '.'` .'.' ~ :`' - ...~ ;.
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Example 2 The process of Example 1 was repeated, using calcium nitrate solution in some cases. From the following table the adhesion benefit of the calcium treatment may be seen and contrasted to the adhesion and corrosion benefit of the cationic polymer~
TABLE II
Silicate Wedge Bend 500 hr. NSS Average (molar) Second Staqe mm loss Scribe Ratinq -0 none 39 3.3 10 .005 none 25 5.0 .005 .005M 17 3.3 Ca(N03) ~
.005 .25 gll so~ids 8 5.5 Polymer III
Comparative Pretreatment B: 24 6.2 Example 3 ;~ ~ -The process of Example 1 was followed, except that a different topcoat paint was used. For comparison, the polymer and the silicate were applied from the same solution in some cases. ; ~
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TABLE III
Wedge Bend 500 hr. NSS Average First StaqeSecond Stage mm loss Scribe Ratina .0125 M silicate 0.85 g/l solids 40 2.75 '~'.',.!'.`','-~',~
of Polymer IV .
.0125 M silicate 1.0 g/l solids 53 0.5 of Polymer III
.0125 M silicate 1.25 g/l solids 42 0 :`~
of Polymer II
.0125 M silicate 21 5.25 combined with 1.25 solids of Polymer II
Comparative Pretreatment A: 41 6.25 ; ~
Comparative Pretreatment B: 30 7.25 ~!'~""`''~''''.' Example 4 The process of Example 3 was followed, except that either an epoxy-functional silane (Huls Hydrosil 2759) or an -~ m aminofunctional silane (Huls Hydrosil 2627) was also used in some cases:
''' ' "' TABLE IV
Wedge Bend 500 hr. NSS Average First Stage Second Staqe mm loss Scribe Rating .0125 M silicate 5.0 g/l Hydrosil 10 8.8 `` .. 'i~."'7:~`''`~
+ 1.25 g/l solids 2627 of Polymer II
.0125 M silicate 5.0 g/l Hydrosil 25 5.8 - 9 ~ :
+ 1.25 g/l solids 2759 .
of Polymer II
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TABLE IV (Cont'd.) ;~
Wedge Bend 500 hr. NSS Average First Staae Second Stage mm loss Scribe_Rating .0125 M silicate 1.25 g/l solids 25 6.0 of Polymer II
+5.0 g/l Hydrosil 2627 ~ ~.
.0125 M silicate 1.25 g/l solids 23 0 of Polymer II
+5.0 g/l Hydrosil .0125 M silicate 10 7.5 + 1.25 g/l solids of Polymer I I
+ 5.0 g/l Hydrosil .0125 M silicate 45 4.0 - ;
+ 1.25 g/l solids of Polymer II
+ 5.0 g/l Hydrosil The organofunctional silane could not be combined with the silicate w;thout the polymer present, as it precipitated. ~ ;
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. . , Example 5 The process of Example 3 was followed, using a different paint system from a different manufacturer. The primer was an .
epoxy and the topcoat was a siliconized polyester. The metal was ~ "~ ~
pretreated using separate and combined solutions, and the ~ ~ :
aminofunctional silane W2S also used in some cases: ~.
TABLE V
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First Second Third Wedge Bend Average Scribe ~`~`.~`. `
Staqe Stage Staqe mm lossRating .0125 M sili- 28 1.0 cate + 1.25 g/l solids of Polymer I I
.0125 M sili- 27 6.0 cate + 1.25 ,~
g/l solids of Polymer II + . ~`:.~-`~
5.0 g/l Hydro- ~N
sil 2627 .0125 M sili- 1.25 g/l 5.0 g/l 24 6.5 ., .... ... -.-~
cate solids of Hydrosil Polymer II 2627 `~
..... . .
2 l 3 08~ b 3~.
Example 6 Three-component pretreatment solutions were prepared over a range of component concentrations in order to test the limits of solubility and efficacy. (As noted in Example 4, the organo functional silane could not be combined with the silicate unless the polymer was present, as it precipitated.) The homogeneities of the solutions were evaluated as follows~
10: Clear 5: Opaque 9: Trace light scattering 1: Slight precipitate 108: Moderate light scattering 0: Heavy precipitate 7: Cloudy, but homogeneous TABLE VI
Sodium Silicate Polymer II Hydrosil Solution (Mol/l) (g~l solids) 2627 (q/l) HomoqeneitY Ratinq D .01 4.0 2.0 9 ::
E .04 1.0 2.0 0 F .01 1.0 8.0 9 G .04 4.0 8.0 7 - : .
H .01 2.5 5.0 10 . ~.
I .025 2.5 8.0 8 J .01 1.0 2.0 9 K .04 1.0 8.0 0 L .025 4.0 5.0 8 M .01 4.0 8.0 9 : ~:.;.~;.1 N .063 6.3 5.0 7 : u:`
O .063 6.3 12.5 5 -P .063 2.5 12.5 0 :
Q .063 2.5 5.0 0 :~`
R .025 5.0 2.0 9 ::
S .025 5.0 8.0 8 T .025 1.0 2.0 1 . : ~::
U .04 5.0 2.0 8 V .01 6.3 12.5 10 ,' '' ~' .` ;",~
.';' ' ~' 2~ 3 088 6 ,' ~ ' '-- ,'.,''.' Thus, a ratio of Polymer II to silicate greater than or equal to 100 9 per mole of silicate was required for homogeneity. `~
Example 7 From Example 6, solutions F, G, J, M, N, O, U, and V were ~-~
used in an Experimental Design study to pretreat galvanized steel, c, , using the process of Example 5. Experimental Design Analysis is a technique familiar to those practiced in the art to maximize the information available from multivariable experiments. (These settings were used as "Inclusions" in a "D-Optimal" Experimental Design, restricted to Polymer II:silicate ratios >= 100 g/mol, `~
analyzed using a quadratic model with low significance terms eliminated.) In addition to the performance tests above, condensing - - -humidity exposure was also evaluated per National Coil Coaters' ,~
Association Technical Bulletin No. III-3 and III-6. (A rating of 10 denotes no blistering occurred.) The test duration was 216 ` ~ ~ J
hours.
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TABLE VII
Condensing Solution Sodium Polymer Wedge Humidity 500 Hr. m (Example Silicate II (9/1 Hydrosil Bend 216 hr. NSS Avg.
6) (Mol/l) solids2 2627 (a/l) Loss (mm) Ava. Ratinq Rating F .01 1.0 8.0 10 9.0 7.0 G .04 4.0 8.0 19 3.5 6.0 -J .01 1.0 2.0 40 8.0 7.0 M .01 4.0 8.0 12 5.0 5.5 N .063 6.3 5.0 23 3.0 4.3 0 .063 6.3 12.5 10 4.5 4.8 U .04 5.0 2.0 29 3.0 3.3 - ~~V .01 6.3 12.5 28 4.0 5.5 : ~ ' Results of the numerical analyses indicated that preferred conditions for performance were lower concentrations of silicate and - -polymer, and higher concentrations of the silane. This is also apparent on comparing results for solution F vs. G, J and M.
Example 8 A concentrate suitable for dilution was prepared at five times the concentrations of the components of solution F. It was a stable, homogeneous mixture exhibiting light scattering typical of a colloid. This solution was diluted to 25% and used to pretreat ~-~
galvanized steel, using the process and paint system of Example 1.
The test duration for condensing humidity was 240 hours.
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Condensing .
Sodium Polymer Wedge Humidity 500 Hr.
Silicate II (g/l Hydrosil Bend 240 hr. NSS Avg.
5Solution(Mol/1) solids) 2627 (g/l) Loss (mm) Avq. Rating Rat1na W.0125 1.25 10.0 22 8.5 8.8 -Comparative Pretreatment C 15 9.0 6.0 ;~ -Example 9 In the following example, the galvanized steel test panels ~-were prepared as in Example 8,~only the pretreatments were spray applied for a 10 second contact time at ambient temperature. In some `~
cases the components of the process were applied in separate stages, with an intervening tap water rinse. In all cases the final solution ~ ~`
was dried in place. The separate-stage processes were preferred. ~-1 15 Results are as follows~
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TABLE IX
240 hr. 500 Hr. ' First Second Wedge Condensing Neutral ; `~
Treatment TreatmentBend Humidity Salt Spray Staae Rinse? Stage _ Loss ~,mm) Ava. Ratinq Avg. Ratinq Solution W No None 26 2 5.0 0.005 M Sili- Yes 4 g/l amino- 7 10 6.0 g/l (act ) propylsilane Polymer I I
0.0125 M Sili- Yes 10 g/l amino- 25 10 6.5 cate + 0 5 propylsilane , x"'~
Polymer I I
Comparative Yes 2.2 g/l as 18 9 6.5 Pretreatment D CrO
Example 10 `~
The following example shows the utility of the inventive ',~
process on aluminum. On aluminum, separate stage addition of the ; '~
silicate/cationic polymer solution and the silane solution was preferred. 3003 alloy aluminum was cleaned and rinsed in the same manner as the galvanized steel in Example 8. Pretreatments were spin-applied to simulate a roll-coat film application or a dip-squeegee followed by a roll-coater. A single-coat polyester paint was applied and cured following the manufacturer's specifications.
Performance tests were as described above, only Acetic Acid Salt ''~
Spray (ASTM B-287) was substituted for neutral salt spray. -'', '~
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TABLE X
240 hr. 500 Hr.
First Second Wedge Condensing Acetic Acid Treatment TreatmentBend Humidity Salt Spray Staae Rinse? Stage Loss (mm) Avq. Ratina Avg. Ratlnq Solution W No None 24 5 3.5 0.0125 M Sili- No 10 g/l amino- 10 9.5 9.5 cate + 0.3 propylsilane g/l (act ) Comparative No None 0 6 9.3 Pretreatment C
Example 11 The following example shows the utility of the inventive process on zinc-aluminum coated steel (Galvalume). As for aluminum, ' separate stage addition of the silicate/cationic polymer solution and the silane solution was preferred. Galvalume was cleaned and rinsed ;~
in the same manner as the galvanized steel in Example 8, and the pretreatments were applied as in Example 9. A two-coat paint system (epoxy primer, polyester topcoat) was applied and cured following the manufacturer's specifications. Performance tests were as described above, using Neutral Salt Spray, and additionally evaluating the width of blistering generated during salt spray exposure at a freshly cut edge of the panel. (The ASTM D-1654 scribe ratings were 10 for all test panels.) :: ,. .. ..~.
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TABLE XI
1000 Hr.
240 hr. Neutral ~-~B
First Second Wedge Condensing Salt Spray Treatment Treatment Bend Humidity Cut Edge Stage Rinse? Staae Loss (mm) Avq. Rating Blisterinq Solution W No None 31 7 5 mm 0.0125 M Sili- No 10 g/l amino- 34 7.5 2 mm :~
cate + 0.3 propylsilane : m:
g/l (act.) Polymer IV
Comparative No None 30 7 3 mm Pretreatment C
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or fluoride ions. Serious concerns have been raised, however, regarding the pollution effects of the chromate or phosphate ~ 'G'-'~
discharged into rivers or waterways by such processes. Due to the high solubility and the strongly oxidizing character of `~
hexavalent chromium ions, conventional chromate conversion coating processes require extensive waste treatment procedures to control their discharge.
While many acceptable chromium-free conversion coatings ~ y have been developed, their utility is often limited to only one ~: ~
type of metal substrate. Many industrial operations, however, involve the sequentlal processing of different types of metals. ''~.,,n~`'","`''~
Unless the undesirable chromium compounds are used, the industrial metal processor is forced to change the conversion coating bath for each different type of metal. This results in unacceptable downtime and higher processing costs.
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2130~6 .
3_ It is desirable, therefore, to have a conversion coating compound which is equally effective on more than one type of metal. This is achieved by the composition and process of the ~n present invention. - -SUMMARY OF THE INVENTION
The present inventors have discovered a metal conversion coating which enhances the corrosion resistance and the adhesion properties of the surface of the metal. It provides excellent paint adhesion and corrosion resistance. The coating of the present invention is formed from an aqueous solution containing an alkaline aqueous silicate, a cationic agent and, optionally, ~ `
an organofunctional silane. `~
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT ' "`
The present inventors have discovered an effective method -of pre-treating metal surfaces by first applying to the surface an aqueous solution of a cationic agent and an alkaline aqueous silicate followed, if desired or needed, by an aqueous organofunctional silane solution. Alternatively, all materials ~ r,~
may be combined into a single solution and applied to the target metal surface in a single application.
The unique feature of the conversion coating composition of the present invention is that it forms an effective coating on the surfaces of metals such as aluminum, steel, zinc coated steel (galvanized) and zinc-aluminum coated steel (Galvalume~
- ' , ,~' . - :
~ .:
2 l 3 o 8 8 ,.. ;~..~' ,' The alkaline silicates used in this invention are derived from either ortho- or condensed silicates. Water soluble salts of the following inorganic anions, in particular the sodium, potassium and ammonium salts thereof, may be used in the practice of this invention. Such compounds are~
Metasilicate - sio32-Orthosilicate - sio44~
Disilicate - Si205-2 .
Mixed Silicates - Na20 xSiO2(where x=1-5) :
Aluminosilicates - Na20 xA1203 ySiO2 (where x+y=3-5) The preferred inorganic silicates are alkaline di- and meta-silicates where the ratio of SiO2 to Na20 is from about 2 to 1 to about 1 to 1. ~ h~`
' ' "' ' ''.:~
~ ' ` '`.`, `'''`
~- 2130~8~
J
~ -5~
- . .- . . .
The cationic agents of the present invention are cationic -~
polymers which are of low to medium molecular weight, have a high .. ,~
charge density and may be cross-linked or linear condensation or ~--,? addition polymers. Their number average molecular weight ranges ".. .
be~ween 1,000 and 600,00C and they are water soluble The charge densities, as determined by the PVSK Colloid Titration Method (H. ~, Terayama, Kayaku no Kenkya, Vol. 1, p. 75, 1948; H. Terayama, -~
Kayaku no Kenkya, Vol. 4, p. 31, 1949; R. Senju, "Koroido ~ ".,~ ;-Tekiteiho", Nankodo, Tokyo, 1969), are active in the range of . ,~
about 1.5 to 12.0 meq/g active polymer.
Those polymers, which have demonstrated the desired performance characteristics, are: ~-: ~:
,,, . -~
PolYmer Descr~ption I polydiallyl dimethyl ammonium chloride (avallable from CPS Chemical as Age Flex) ~ ;~
II condensat;on product of dimethylamine plus epichlorohydrin plus ethylenediamine (avaif;ble from American Cyanamid as I I I condensation product of dimethylamine plus epichlorohydrin (U.S. Patent No. 3,738,945 IV condensation product of diethylenetriamine plus adipic acid plus epichlorohydrin (Betz ~ .
Laboratories, Inc., Polymer 1175) V condensation product of hexamethylenediamine st~ll bottoms plus ethylene dichloride plus epichlorohydrin tavailable from Monsanto as :~
2 1 3 ~ ~ ~ fi The organofunctional silanes are hydrolyzed and are --~
prepared from the respective alkoxysilanes where one or more alkoxide groups are converted to a silanol tSi-OH, or Si-0-) function through acid or base hydrolysis. These may be prepared 5 from a wide variety of organofunctional alkoxysilanes. The ;
techniques are familiar to those practiced in the art and are readily available in the literature. See, for example, E.P.
Pluddemann, "Silane Coupling Agents", 2nd. ed., Plenum Press, 1991, chapter 2, herein incorporated by reference.
The organofunctional silanes which exhibit the desired utility in this invention are aminosilanes. The preferable aminosilane is a hydrolyzed aminopropyltrimethoxysilane. This compound is commercially available as an approximately 20% active aqueous solution from Huls America and is designated as Hydrosil 2627. `"~
The alkaline silicate and cationic polymer may be applied ~ ~
either as a single aqueous solution, or in sequence with or with- ;~ v out an intervening rinse step, depending on the solubilities of the materials. Concentrations are from about .01 to about .07 molar of the alkaline silicate. For the cationic polymers, a weight ratio of about from 10 to about 700 grams of polymer solids per mole of silicate is utilized. For the organofunctional ;~
silaoe, a weight ratio of about 5 to aboot 250 grams of 21 3 D ~
-7- -~
,' ' ~
organosilane solids per mole of silicate is utilized. A preferred pretreatment process comprises a solution which contains from 0.01 i=
to 0.02 molar alkaline silicate with from 1.0 to 1.3 g/l of cat- `~;~ q-;~, ionic polymer solids. This is followed by an optional water rinse ~`~
and then application of a solution of 10 to 13 g/l of the organo-functional silane.
The treatment solution(s) may be applied to the metal -~
surface to be treated by any conventional means such as spraying, wetting by dip squeegee, flow coating, roll coating and the like.
Roll coating is generally preferred. The final solution of the present invention is preferably dried in place.
The following illustrative scheme summarizes the several possible sequences of application contemplated in this invention. ~ ~ ;
In the scheme, "+" denotes that the agents are combined in solution, "/" denotes a separate solution or stage and "*" denotes that the step may be omitted.
alkaline silicate/rinse*/cationic polymer/rinse*/organo-functional silane alkaline silicated + cationic polymer/rinse*/organo-functional silane alkaline silicate + cationic polymer + organofunctional -~
silane.
,' :-'' ~ ' .~'"'' I 3 0 8 8 ~
., ~ ~....
~ . .. ....
-8- ' .,..... ~
EXAMPLES -The present invention will now be further described with -reference to a number of specific examp1es which are to be - ~ ~
regarded solely as illustrative and not as restricting the scope ",''"'~'!'' of the present invention.
Example 1 -The following test procedure was followed. Hot dipped galvanized steel panels were obtained from ACT Corp. They were ~:
spray cleaned with a hot alkaline surfactant solution in water, rinsed, passed through squeegee rolls to remove most of the water, ;~
and then spin-coated by flooding the panel surface with the solutions below. The wet panels were spun for 10 sec. after the solution was applied. The panels were dried in place on the spinner with a stream of hot air. - ~-n~
Comparative pretreatment solutions are as follows:
. ., , .~.. .
A. 15% Betz Permatreat 1006, a non-Cr pretreatment for galvanized steel containing dihydrofluorozirconic acid and an acrylic acid copolymer.
B. 11% Betz Permatreat 1500, a mixed ~ -hexavalent-trivalent chromium pretreatment , ~ containing silicon dioxide.
' .'-` .
2 ~ 3 0 8 ~ 6 C. 15% Betz Permatreat 1500.
D. 1.2% solution of the product of Example 13 ~-of W0 85/05131 (utilizes a chromate based final rinse).
The panels were painted with a two-coat epoxy/fluorocarbon paint system specified for galvanized steel, and cured in accordance with the manufacturer's specifications.
The adhesion and corrosion performance of the treated and painted galvanized steel were evaluated using a Wedge Bend test and a 500 hour Neutral Salt Spray test, respectively. In the Wedge Bend test, a tapered 180 degree bend in the metal is formed by first turning it to a radius of about 0.5 cm and then flatten-ing the metal to a near zero radius. The stressed surface is then subjected to a tape pull, and the amount of paint loss (in mm) is recorded. 0 mm is perfect. Neutral Salt Spray (NSS) tests were carried out in accordance with ASTM B-117, with the scribe and rating methods following ASTM D-1654 Test Method B, Procedure A
7.2. The ratings are from 0 to 10 (10 = perfect).
~:
; . :
2130886 ~ ~
In some cases, a condensing humidity test was employed.
This test followed the protocol of National Coil Coaters' Association Technical Bulletin No. III-3 and III-6. Blistering is rated on a scale of 0 to 10 (10=perfect). -~
The response of adhesion and corrosion performance from the sequential application of the silicate and the cationic polymer will be appreciated from the following table~
TABLE I
Silicate Polymer Wedge Bend 500 hr NSS Average `~
(molar) PolYmer q/l solids mm loss Scribe Ratina .0125 0 26 5.5 .0125 III 0.25 23 6.0 .0125 III 1.0 13 5.8 O III 1.0 44 5.2 .0125 II 0.31 26 5.0 .0125 II 1.25 0 6.5 ;:
O II 1.25 31 5.8 Comparative Pretreatment A: 11 5.5 Comparative Pretreatment B: 0 6.5 '.'` .'.' ~ :`' - ...~ ;.
~ ;'." ~,`.'';
~ ' .. ' `
213~8~
Example 2 The process of Example 1 was repeated, using calcium nitrate solution in some cases. From the following table the adhesion benefit of the calcium treatment may be seen and contrasted to the adhesion and corrosion benefit of the cationic polymer~
TABLE II
Silicate Wedge Bend 500 hr. NSS Average (molar) Second Staqe mm loss Scribe Ratinq -0 none 39 3.3 10 .005 none 25 5.0 .005 .005M 17 3.3 Ca(N03) ~
.005 .25 gll so~ids 8 5.5 Polymer III
Comparative Pretreatment B: 24 6.2 Example 3 ;~ ~ -The process of Example 1 was followed, except that a different topcoat paint was used. For comparison, the polymer and the silicate were applied from the same solution in some cases. ; ~
~; , ,. .;
2 t 3 0 8 8 ~
TABLE III
Wedge Bend 500 hr. NSS Average First StaqeSecond Stage mm loss Scribe Ratina .0125 M silicate 0.85 g/l solids 40 2.75 '~'.',.!'.`','-~',~
of Polymer IV .
.0125 M silicate 1.0 g/l solids 53 0.5 of Polymer III
.0125 M silicate 1.25 g/l solids 42 0 :`~
of Polymer II
.0125 M silicate 21 5.25 combined with 1.25 solids of Polymer II
Comparative Pretreatment A: 41 6.25 ; ~
Comparative Pretreatment B: 30 7.25 ~!'~""`''~''''.' Example 4 The process of Example 3 was followed, except that either an epoxy-functional silane (Huls Hydrosil 2759) or an -~ m aminofunctional silane (Huls Hydrosil 2627) was also used in some cases:
''' ' "' TABLE IV
Wedge Bend 500 hr. NSS Average First Stage Second Staqe mm loss Scribe Rating .0125 M silicate 5.0 g/l Hydrosil 10 8.8 `` .. 'i~."'7:~`''`~
+ 1.25 g/l solids 2627 of Polymer II
.0125 M silicate 5.0 g/l Hydrosil 25 5.8 - 9 ~ :
+ 1.25 g/l solids 2759 .
of Polymer II
,: ................... ................... ............ ............................... ... ... .... .....
.. ~ - -; ~.
~ '-::. ~ ' -' ', .,............................... 213~8~6 ,.
:~:
-13- ~ ~;
TABLE IV (Cont'd.) ;~
Wedge Bend 500 hr. NSS Average First Staae Second Stage mm loss Scribe_Rating .0125 M silicate 1.25 g/l solids 25 6.0 of Polymer II
+5.0 g/l Hydrosil 2627 ~ ~.
.0125 M silicate 1.25 g/l solids 23 0 of Polymer II
+5.0 g/l Hydrosil .0125 M silicate 10 7.5 + 1.25 g/l solids of Polymer I I
+ 5.0 g/l Hydrosil .0125 M silicate 45 4.0 - ;
+ 1.25 g/l solids of Polymer II
+ 5.0 g/l Hydrosil The organofunctional silane could not be combined with the silicate w;thout the polymer present, as it precipitated. ~ ;
:::~ :::
~: ~ :-''`''`
.
l - 2~308~6 ~ :
-14~
. . , Example 5 The process of Example 3 was followed, using a different paint system from a different manufacturer. The primer was an .
epoxy and the topcoat was a siliconized polyester. The metal was ~ "~ ~
pretreated using separate and combined solutions, and the ~ ~ :
aminofunctional silane W2S also used in some cases: ~.
TABLE V
- :. .. .
First Second Third Wedge Bend Average Scribe ~`~`.~`. `
Staqe Stage Staqe mm lossRating .0125 M sili- 28 1.0 cate + 1.25 g/l solids of Polymer I I
.0125 M sili- 27 6.0 cate + 1.25 ,~
g/l solids of Polymer II + . ~`:.~-`~
5.0 g/l Hydro- ~N
sil 2627 .0125 M sili- 1.25 g/l 5.0 g/l 24 6.5 ., .... ... -.-~
cate solids of Hydrosil Polymer II 2627 `~
..... . .
2 l 3 08~ b 3~.
Example 6 Three-component pretreatment solutions were prepared over a range of component concentrations in order to test the limits of solubility and efficacy. (As noted in Example 4, the organo functional silane could not be combined with the silicate unless the polymer was present, as it precipitated.) The homogeneities of the solutions were evaluated as follows~
10: Clear 5: Opaque 9: Trace light scattering 1: Slight precipitate 108: Moderate light scattering 0: Heavy precipitate 7: Cloudy, but homogeneous TABLE VI
Sodium Silicate Polymer II Hydrosil Solution (Mol/l) (g~l solids) 2627 (q/l) HomoqeneitY Ratinq D .01 4.0 2.0 9 ::
E .04 1.0 2.0 0 F .01 1.0 8.0 9 G .04 4.0 8.0 7 - : .
H .01 2.5 5.0 10 . ~.
I .025 2.5 8.0 8 J .01 1.0 2.0 9 K .04 1.0 8.0 0 L .025 4.0 5.0 8 M .01 4.0 8.0 9 : ~:.;.~;.1 N .063 6.3 5.0 7 : u:`
O .063 6.3 12.5 5 -P .063 2.5 12.5 0 :
Q .063 2.5 5.0 0 :~`
R .025 5.0 2.0 9 ::
S .025 5.0 8.0 8 T .025 1.0 2.0 1 . : ~::
U .04 5.0 2.0 8 V .01 6.3 12.5 10 ,' '' ~' .` ;",~
.';' ' ~' 2~ 3 088 6 ,' ~ ' '-- ,'.,''.' Thus, a ratio of Polymer II to silicate greater than or equal to 100 9 per mole of silicate was required for homogeneity. `~
Example 7 From Example 6, solutions F, G, J, M, N, O, U, and V were ~-~
used in an Experimental Design study to pretreat galvanized steel, c, , using the process of Example 5. Experimental Design Analysis is a technique familiar to those practiced in the art to maximize the information available from multivariable experiments. (These settings were used as "Inclusions" in a "D-Optimal" Experimental Design, restricted to Polymer II:silicate ratios >= 100 g/mol, `~
analyzed using a quadratic model with low significance terms eliminated.) In addition to the performance tests above, condensing - - -humidity exposure was also evaluated per National Coil Coaters' ,~
Association Technical Bulletin No. III-3 and III-6. (A rating of 10 denotes no blistering occurred.) The test duration was 216 ` ~ ~ J
hours.
~ ~--',' ~''~"' J
' ~i ~' ' ', 213o~g~ ~ ~
~.
TABLE VII
Condensing Solution Sodium Polymer Wedge Humidity 500 Hr. m (Example Silicate II (9/1 Hydrosil Bend 216 hr. NSS Avg.
6) (Mol/l) solids2 2627 (a/l) Loss (mm) Ava. Ratinq Rating F .01 1.0 8.0 10 9.0 7.0 G .04 4.0 8.0 19 3.5 6.0 -J .01 1.0 2.0 40 8.0 7.0 M .01 4.0 8.0 12 5.0 5.5 N .063 6.3 5.0 23 3.0 4.3 0 .063 6.3 12.5 10 4.5 4.8 U .04 5.0 2.0 29 3.0 3.3 - ~~V .01 6.3 12.5 28 4.0 5.5 : ~ ' Results of the numerical analyses indicated that preferred conditions for performance were lower concentrations of silicate and - -polymer, and higher concentrations of the silane. This is also apparent on comparing results for solution F vs. G, J and M.
Example 8 A concentrate suitable for dilution was prepared at five times the concentrations of the components of solution F. It was a stable, homogeneous mixture exhibiting light scattering typical of a colloid. This solution was diluted to 25% and used to pretreat ~-~
galvanized steel, using the process and paint system of Example 1.
The test duration for condensing humidity was 240 hours.
~. ~; ,;
~.~
.-: ~
~:
.... . . ~ . . ~ -.
.... :...~''~.~' `' ;:'', ' '.~
2 1 3 ~ 8 ~
' ~;'' TABLE VI I I
Condensing .
Sodium Polymer Wedge Humidity 500 Hr.
Silicate II (g/l Hydrosil Bend 240 hr. NSS Avg.
5Solution(Mol/1) solids) 2627 (g/l) Loss (mm) Avq. Rating Rat1na W.0125 1.25 10.0 22 8.5 8.8 -Comparative Pretreatment C 15 9.0 6.0 ;~ -Example 9 In the following example, the galvanized steel test panels ~-were prepared as in Example 8,~only the pretreatments were spray applied for a 10 second contact time at ambient temperature. In some `~
cases the components of the process were applied in separate stages, with an intervening tap water rinse. In all cases the final solution ~ ~`
was dried in place. The separate-stage processes were preferred. ~-1 15 Results are as follows~
.,.,~,,.",,.;",.....
~p~
, .! 1, . .
:
','```~`` ~'.'','' `'.',,',,`''.'...':',~'.'"' - 21 3~8~ ~
, ~ .
.:
TABLE IX
240 hr. 500 Hr. ' First Second Wedge Condensing Neutral ; `~
Treatment TreatmentBend Humidity Salt Spray Staae Rinse? Stage _ Loss ~,mm) Ava. Ratinq Avg. Ratinq Solution W No None 26 2 5.0 0.005 M Sili- Yes 4 g/l amino- 7 10 6.0 g/l (act ) propylsilane Polymer I I
0.0125 M Sili- Yes 10 g/l amino- 25 10 6.5 cate + 0 5 propylsilane , x"'~
Polymer I I
Comparative Yes 2.2 g/l as 18 9 6.5 Pretreatment D CrO
Example 10 `~
The following example shows the utility of the inventive ',~
process on aluminum. On aluminum, separate stage addition of the ; '~
silicate/cationic polymer solution and the silane solution was preferred. 3003 alloy aluminum was cleaned and rinsed in the same manner as the galvanized steel in Example 8. Pretreatments were spin-applied to simulate a roll-coat film application or a dip-squeegee followed by a roll-coater. A single-coat polyester paint was applied and cured following the manufacturer's specifications.
Performance tests were as described above, only Acetic Acid Salt ''~
Spray (ASTM B-287) was substituted for neutral salt spray. -'', '~
~. ~....-2~3~
TABLE X
240 hr. 500 Hr.
First Second Wedge Condensing Acetic Acid Treatment TreatmentBend Humidity Salt Spray Staae Rinse? Stage Loss (mm) Avq. Ratina Avg. Ratlnq Solution W No None 24 5 3.5 0.0125 M Sili- No 10 g/l amino- 10 9.5 9.5 cate + 0.3 propylsilane g/l (act ) Comparative No None 0 6 9.3 Pretreatment C
Example 11 The following example shows the utility of the inventive process on zinc-aluminum coated steel (Galvalume). As for aluminum, ' separate stage addition of the silicate/cationic polymer solution and the silane solution was preferred. Galvalume was cleaned and rinsed ;~
in the same manner as the galvanized steel in Example 8, and the pretreatments were applied as in Example 9. A two-coat paint system (epoxy primer, polyester topcoat) was applied and cured following the manufacturer's specifications. Performance tests were as described above, using Neutral Salt Spray, and additionally evaluating the width of blistering generated during salt spray exposure at a freshly cut edge of the panel. (The ASTM D-1654 scribe ratings were 10 for all test panels.) :: ,. .. ..~.
: ~ , ,. ,. . ,-, ... . ..~-.. ~
,- i 2 ~ 3 0 (~
TABLE XI
1000 Hr.
240 hr. Neutral ~-~B
First Second Wedge Condensing Salt Spray Treatment Treatment Bend Humidity Cut Edge Stage Rinse? Staae Loss (mm) Avq. Rating Blisterinq Solution W No None 31 7 5 mm 0.0125 M Sili- No 10 g/l amino- 34 7.5 2 mm :~
cate + 0.3 propylsilane : m:
g/l (act.) Polymer IV
Comparative No None 30 7 3 mm Pretreatment C
~ , ~ ;~.'................ ...... ................ .......... ........... ................... ......, - . ................ ...... ................ .......... ........... ................... . .....- ;
~''.,'~ ~'. .' ~: ,"" " ,.,.,.. ,~ ", . ~ . . - .: ~ -.,,, .-,.
..... ~ ~ .
Claims (24)
1. An aqueous solution for coating a metal surface comprising a cationic polymer, an alkaline aqueous silicate and an organofunctional silane.
2. The aqueous solution of claim 1 wherein the cationic polymer is selected from the group consisting of:
-polydiallyl dimethyl ammonium chloride, -the condensation product of dimethylamine plus epichlorohydrin plus ethylenediamine, -the condensation product of dimethylamine plus epichlorohydrin, -the condensation product of diethylenetriamine plus adipic acid plus epichlorohydrin, and -the condensation product of hexamethylene diamine still bottoms plus ethylenedichloride plus epichlorohydrin.
-polydiallyl dimethyl ammonium chloride, -the condensation product of dimethylamine plus epichlorohydrin plus ethylenediamine, -the condensation product of dimethylamine plus epichlorohydrin, -the condensation product of diethylenetriamine plus adipic acid plus epichlorohydrin, and -the condensation product of hexamethylene diamine still bottoms plus ethylenedichloride plus epichlorohydrin.
3. The aqueous solution of claim 1 wherein the inorganic silicate is selected from the group consisting of metasilicate, orthosilicate, disilicate, mixed silicate, and aluminosilicate.
4. The aqueous solution of claim 3 wherein the silicate comprises SiO2 and Na2O.
5. The aqueous solution of claim 1 wherein the organofunctional silane is hydrolyzed aminopropyltrimethoxysilane.
6. The aqueous solution of claim 1 containing approximately .008% to 0.2% cationic polymer, approximately .005% to 0.12%
inorganic silicate (expressed as SiO2) and approximately .01% to 0.25% organofunctional silane.
inorganic silicate (expressed as SiO2) and approximately .01% to 0.25% organofunctional silane.
7. The aqueous solution of claim 1 comprising an aqueous concentrate containing from about 0.8% to 2% cationic polymer, from about 0.5% to 1.2% alkaline aqueous silicate and from about 1.0% to 2.5% organofunctional silane.
8. A method of coating a metal surface comprising contacting the metal surface with an aqueous solution containing a cationic polymer, an alkaline aqueous silicate and an organo-functional silane.
9. The method of claim 8 wherein the cationic polymer is selected from the group consisting of:
-polydiallyl dimethyl ammonium chloride, -the condensation product of dimethylamine plus epichlorohydrin plus ethylenediamine, -the condensation product of dimethylamine plus epichlorohydrin, -the condensation product of diethylenetriamine plus adipic acid plus epichlorohydrin, and -the condensation product of hexamethylene diamine still bottoms plus ethylenedichloride plus epichlorohydrin.
-polydiallyl dimethyl ammonium chloride, -the condensation product of dimethylamine plus epichlorohydrin plus ethylenediamine, -the condensation product of dimethylamine plus epichlorohydrin, -the condensation product of diethylenetriamine plus adipic acid plus epichlorohydrin, and -the condensation product of hexamethylene diamine still bottoms plus ethylenedichloride plus epichlorohydrin.
10. The method of claim 8 wherein the alkaline aqueous silicate is selected from the group consisting of metasilicate, orthosilicate, disilicate, mixed silicate and aluminosilicate.
11. The method of claim 10 wherein the silicate contains SiO2 and Na2O.
12. The method of claim 8 wherein the organofunctional silane is hydrolyzed aminopropyl trimethoxysilane.
13. The method of claim 8 wherein the aqueous solution contains approximately 0.008% to 0.2% cationic polymer, approximate-ly 0.005% to 0.12% alkaline aqueous silicate (expressed as SiO2) and approximately 0.01% to 0.25% organofunctional silane.
14. The method of claim 8 wherein the metal is selected from the group consisting of aluminum, steel, galvanized steel and zinc-aluminum coated steel.
15. The method of claim 8 wherein the aqueous solution is applied to the metal surface in a single step by spraying, flow coating, roll coating or wetting by dip-squeegee.
16. A method of coating a metal surface comprising contacting the metal surface, in sequence, with a first aqueous solution containing a cationic polymer and an alkaline aqueous silicate followed by a second aqueous solution containing an organofunctional silane.
17. The method of claim 16 wherein the cationic polymer is selected from the group consisting of:
-polydiallyl dimethyl ammonium chloride, -the condensation product of dimethylamine plus epichlorohydrin plus ethylenediamine, -the condensation product of dimethylamine plus epichlorohydrin, -the condensation product of diethylenetriamine plus adipic acid plus epichlorohydrin, and -the condensation product of hexamethylene diamine still bottoms plus ethylenedichloride plus epichlorohydrin.
-polydiallyl dimethyl ammonium chloride, -the condensation product of dimethylamine plus epichlorohydrin plus ethylenediamine, -the condensation product of dimethylamine plus epichlorohydrin, -the condensation product of diethylenetriamine plus adipic acid plus epichlorohydrin, and -the condensation product of hexamethylene diamine still bottoms plus ethylenedichloride plus epichlorohydrin.
18. The method of claim 16 wherein the alkaline aqueous silicate is selected from the group consisting of metasilicate, orthosilicate, disilicate, mixed silicate and aluminosilicate.
19. The method of claim 18 wherein the silicate contains SiO2 and Na2O.
20. The method of claim 16 wherein the organofunctional silane is hydrolyzed aminopropyl trimethoxysilane.
21. The method of claim 16 wherein the first aqueous solution contains approximately 0.008% to 0.2% cationic polymer and approximately 0.005% to 0.12% alkaline aqueous silicate (expressed as SiO2) and the second aqueous solution contains approximately 0.01% to 0.25% organofunctional silane.
22. The method of claim 16 wherein the metal is selected from the group consisting of aluminum, steel, galvanized steel and zinc-aluminum coated steel.
23. The method of claim 16 wherein the aqueous solution is applied to the metal surface in a single step by spraying, flow coating, roll coating or wetting by dip-squeegee.
24. The method of claim 16 further comprising a water rinse after contacting the metal surface with the first aqueous solution and before the second aqueous solution.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US08/152,806 | 1993-11-16 | ||
| US08/152,806 US5389405A (en) | 1993-11-16 | 1993-11-16 | Composition and process for treating metal surfaces |
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| Publication Number | Publication Date |
|---|---|
| CA2130886A1 true CA2130886A1 (en) | 1995-05-17 |
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| CA002130886A Abandoned CA2130886A1 (en) | 1993-11-16 | 1994-08-25 | Composition and process for treating metal surfaces |
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| CA (1) | CA2130886A1 (en) |
Families Citing this family (48)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5637404A (en) * | 1992-01-31 | 1997-06-10 | Aluminum Company Of America | Reflective aluminum strip |
| JPH07216268A (en) * | 1994-02-03 | 1995-08-15 | Nippon Parkerizing Co Ltd | Surface treatment agent for zinc-containing metal-coated steel sheet, excellent in corrosion resistance and coating adhesion |
| US6059867A (en) * | 1995-10-10 | 2000-05-09 | Prc-Desoto International, Inc. | Non-chromate corrosion inhibitors for aluminum alloys |
| JP4194654B2 (en) * | 1995-10-10 | 2008-12-10 | ピーアールシー−デソト インターナショナル，インコーポレイティド | Nonchromate corrosion inhibitor for aluminum alloys |
| US5868819A (en) * | 1996-05-20 | 1999-02-09 | Metal Coatings International Inc. | Water-reducible coating composition for providing corrosion protection |
| US6291020B1 (en) | 1996-08-08 | 2001-09-18 | Betzdearborn Inc. | Composition and process for treating metal surfaces |
| US6099714A (en) * | 1996-08-30 | 2000-08-08 | Sanchem, Inc. | Passification of tin surfaces |
| DE19642723A1 (en) * | 1996-10-17 | 1998-04-30 | Suratech Gmbh | Improved bonding of paint or adhesive with aluminium or its alloys |
| DE19642725A1 (en) * | 1996-10-17 | 1998-04-30 | Suratech Gmbh | Improved bonding of paint or adhesive with galvanised steel or iron |
| US5759629A (en) * | 1996-11-05 | 1998-06-02 | University Of Cincinnati | Method of preventing corrosion of metal sheet using vinyl silanes |
| US5750197A (en) | 1997-01-09 | 1998-05-12 | The University Of Cincinnati | Method of preventing corrosion of metals using silanes |
| US5972433A (en) * | 1997-12-05 | 1999-10-26 | Calgon Corporation | Method for treatment of metal substrates using Mannich-derived polyethers |
| DE19814605A1 (en) * | 1998-04-01 | 1999-10-07 | Kunz Gmbh | Means for sealing metallic substrates, in particular of zinc or zinc alloys |
| US6620519B2 (en) | 1998-04-08 | 2003-09-16 | Lockheed Martin Corporation | System and method for inhibiting corrosion of metal containers and components |
| US6162547A (en) * | 1998-06-24 | 2000-12-19 | The University Of Cinncinnati | Corrosion prevention of metals using bis-functional polysulfur silanes |
| JP4165943B2 (en) * | 1998-11-18 | 2008-10-15 | 日本ペイント株式会社 | Rust-proof coating agent for zinc-coated steel and uncoated steel |
| US6416869B1 (en) | 1999-07-19 | 2002-07-09 | University Of Cincinnati | Silane coatings for bonding rubber to metals |
| US6126997A (en) * | 1999-02-03 | 2000-10-03 | Bulk Chemicals, Inc. | Method for treating magnesium die castings |
| US7344607B2 (en) * | 1999-07-08 | 2008-03-18 | Ge Betz, Inc. | Non-chromate conversion coating treatment for metals |
| US6827981B2 (en) | 1999-07-19 | 2004-12-07 | The University Of Cincinnati | Silane coatings for metal |
| US6270884B1 (en) | 1999-08-02 | 2001-08-07 | Metal Coatings International Inc. | Water-reducible coating composition for providing corrosion protection |
| US6358616B1 (en) | 2000-02-18 | 2002-03-19 | Dancor, Inc. | Protective coating for metals |
| US7317053B1 (en) | 2000-07-10 | 2008-01-08 | Hercules Incorporated | Compositions for imparting desired properties to materials |
| US6461683B1 (en) | 2000-10-04 | 2002-10-08 | Lockheed Martin Corporation | Method for inorganic paint to protect metallic surfaces exposed to moisture, salt and extreme temperatures against corrosion |
| EP1492904A2 (en) * | 2001-08-03 | 2005-01-05 | Elisha Holding LLC | An electroless process for treating metallic surfaces and products formed thereby |
| WO2003076534A1 (en) * | 2002-03-05 | 2003-09-18 | Chemnova Technologies, Inc. | Surface base-coat formulation for metal alloys |
| US20040137239A1 (en) * | 2002-11-14 | 2004-07-15 | Klaus-Peter Klos | Processes for electrocoating and articles made therefrom |
| US20060193988A1 (en) * | 2003-02-25 | 2006-08-31 | Manfred Walter | Method for coating metallic surfaces with a mixture containing at least two silanes |
| US20050183793A1 (en) * | 2004-02-25 | 2005-08-25 | Hyung-Joon Kim | Method of improving the performance of organic coatings for corrosion resistance |
| JP2008508429A (en) * | 2004-08-03 | 2008-03-21 | ヒェメタル ゲゼルシャフト ミット ベシュレンクテル ハフツング | Protecting metal surfaces with corrosion-inhibiting coatings |
| US8101014B2 (en) * | 2004-11-10 | 2012-01-24 | Chemetall Gmbh | Process for coating metallic surfaces with a multicomponent aqueous composition |
| CA2586673C (en) * | 2004-11-10 | 2012-10-23 | Chemetall Gmbh | Method for coating metallic surfaces with an aqueous multi-component composition |
| US20060099332A1 (en) | 2004-11-10 | 2006-05-11 | Mats Eriksson | Process for producing a repair coating on a coated metallic surface |
| US20080138615A1 (en) * | 2005-04-04 | 2008-06-12 | Thomas Kolberg | Method for Coating Metallic Surfaces with an Aqueous Composition and Said Composition |
| US10041176B2 (en) | 2005-04-07 | 2018-08-07 | Momentive Performance Materials Inc. | No-rinse pretreatment methods and compositions |
| DE102007045186A1 (en) * | 2007-09-21 | 2009-04-09 | Continental Teves Ag & Co. Ohg | Residue-free, layer-forming, aqueous sealing system for metallic silane-based surfaces |
| JP5322000B2 (en) * | 2007-12-07 | 2013-10-23 | ディップソール株式会社 | Surface treatment aqueous solution and treatment method for forming a corrosion-resistant film on zinc or zinc alloy plating |
| US8268975B2 (en) * | 2009-04-03 | 2012-09-18 | Dow Agrosciences Llc | Demulsification compositions, systems and methods for demulsifying and separating aqueous emulsions |
| CN101775596B (en) * | 2010-04-06 | 2011-08-03 | 中南大学 | Chromium-free passivation method of aluminum pipe for evaporator of refrigerator or freezer and passivation solution thereof |
| BR112013010384A2 (en) | 2010-10-27 | 2016-08-02 | Chemetall Gmbh | aqueous composition for the pretreatment of a metal surface before another coating or for the treatment of that surface |
| DE102011001140A1 (en) * | 2011-03-08 | 2012-09-13 | Thyssenkrupp Steel Europe Ag | Flat steel product, method for producing a flat steel product and method for producing a component |
| CN103087569B (en) * | 2012-12-18 | 2016-01-06 | 芜湖恒坤汽车部件有限公司 | A kind of stainless steel plate surface silanization protective agent for surface treatment and preparation method thereof |
| CN103046095B (en) * | 2012-12-28 | 2015-04-08 | 东莞市富默克化工有限公司 | Electroplated metal antiblushing agent and preparation method and using method thereof |
| BR112017022024A2 (en) | 2015-04-15 | 2018-07-03 | Henkel Ag & Co. Kgaa | thin corrosion protective coatings incorporating polyamidoamine polymers |
| JP2017203208A (en) * | 2015-07-09 | 2017-11-16 | 株式会社神戸製鋼所 | Aqueous solution for metal surface treatment, method for treating metal surface and joined body |
| US11939490B2 (en) | 2017-07-31 | 2024-03-26 | Momentive Performance Materials Inc. | Curable surface-protective coating composition, processes for its preparation and application to a metallic substrate and resulting coated metallic substrate |
| BR112020022489A2 (en) * | 2018-06-07 | 2021-02-09 | Graver Technologies Llc | filter medium for the removal of particles, ions and biological materials and discoloration in a sugar purification process, and the use thereof |
| CN110747456A (en) * | 2019-12-02 | 2020-02-04 | 广州市杰裕联环保技术有限公司 | Alkaline washing-free composite silane and application thereof |
Family Cites Families (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3372052A (en) * | 1964-12-24 | 1968-03-05 | Union Carbide Corp | Water repellent for masonry |
| AT283078B (en) * | 1968-09-16 | 1970-07-27 | Henkel & Cie Gmbh | Process for the aftertreatment of phosphate layers on metal surfaces |
| US3649320A (en) * | 1970-02-16 | 1972-03-14 | Du Pont | Coupling agent copolymers of amine silicates and organofunctional silanes |
| US3816152A (en) * | 1970-02-16 | 1974-06-11 | Du Pont | Coupling agent copolymer dispersions of silicic acids and organofunctional silanes |
| US3804639A (en) * | 1970-07-13 | 1974-04-16 | Standard Paint & Varnish Co | Coating composition having polymeric siloxane binder and dispersed filler |
| US3832204A (en) * | 1970-09-08 | 1974-08-27 | D Boaz | Silicate polymer vehicles for use in protective coatings and process of making |
| US4277284A (en) * | 1978-04-28 | 1981-07-07 | Union Carbide Corporation | Single-package zinc-rich coatings |
| US4290811A (en) * | 1980-03-31 | 1981-09-22 | Rust-Oleum Corporation | Method of producing silicate binders and coatings |
| AU4295885A (en) * | 1984-05-04 | 1985-11-28 | Amchem Products Inc. | Metal treatment |
| US5147557A (en) * | 1988-02-29 | 1992-09-15 | Betz Laboratories, Inc. | Paint spray booth treatment program for water base and water base and water base blended with oil base paints |
| AU651096B2 (en) * | 1990-03-27 | 1994-07-14 | Courtaulds Coatings (Holdings) Limited | Coating composition |
| US5053081A (en) * | 1990-04-02 | 1991-10-01 | Oakite Products, Inc. | Composition and method for treatment of conversion coated metal surfaces with an aqueous solution of 3-aminopropyltriethoxy silane and titanium chelate |
| US5108793A (en) * | 1990-12-24 | 1992-04-28 | Armco Steel Company, L.P. | Steel sheet with enhanced corrosion resistance having a silane treated silicate coating |
| DE4211269A1 (en) * | 1992-04-03 | 1993-10-07 | Wacker Chemie Gmbh | Emulsions containing acylated amino functional organopolysiloxane |
-
1993
- 1993-11-16 US US08/152,806 patent/US5389405A/en not_active Expired - Fee Related
-
1994
- 1994-08-25 CA CA002130886A patent/CA2130886A1/en not_active Abandoned
- 1994-10-31 US US08/332,278 patent/US5451431A/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| US5451431A (en) | 1995-09-19 |
| US5389405A (en) | 1995-02-14 |
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