HK1162038A - Electrodepositable coating composition comprising silane and yttrium - Google Patents

Description

Electrodepositable coating composition comprising silane and yttrium

Cross Reference to Related Applications

The present application claims priority from U.S. provisional application No. 61/147,583 filed on 27/1/2009.

Background

Technical Field

The present invention relates generally to electrodepositable coating compositions.

Background information

Electrodeposition as a coating application method includes depositing an electrodepositable coating composition on an electrically conductive substrate under the influence of an applied electrical potential. Electrodeposition is becoming increasingly important in the coatings industry because electrodeposition provides increased pigment utilization, improved corrosion protection, and low environmental pollution compared to non-electrophoretic coating methods.

In the electrodeposition process, the electrodepositable coating composition is deposited on a substrate that has been previously treated with a pretreatment solution, such as a zinc phosphate pretreatment solution, prior to the electrodeposition process. The elimination of the pretreatment step prior to the electrodeposition process will reduce the costs associated with coating the substrate as well as eliminate any chemical by-products generated during the pretreatment step. Furthermore, in an automotive OEM factory setting, the elimination of pre-processing equipment would mean that the size of the factory could potentially be scaled down or useful factory space could be reclaimed.

Accordingly, the present invention relates to electrodepositable coating compositions that can be applied to an unpretreated substrate.

Summary of The Invention

The present invention relates to electrodepositable coating compositions comprising (i) a film-forming polymer, (ii) yttrium, and (iii) a silane that does not contain ethylenically unsaturated double bonds. The invention further relates to substrates coated with such coating compositions.

The present invention also relates to an electrodepositable coating composition consisting essentially of: (i) a film-forming polymer comprising reactive functional groups, (ii) yttrium, (iii) a silane that does not contain an ethylenically unsaturated double bond; (iv) a crosslinker reactive with the reactive functional groups of the film-forming polymer; and (v) a catalyst.

The present invention also relates to electrodepositable coating compositions comprising (i) a film-forming polymer, (ii) yttrium, and (iii) an aminosilane. The invention further relates to substrates coated with such coating compositions.

Detailed Description

Unless otherwise expressly stated, all numbers such as those expressing values, ranges, amounts or percentages used herein are to be understood as modified by the word "about", even if the term does not expressly appear. Plural encompasses singular and vice versa. For example, although reference is made herein to "a" film-forming polymer, "an" yttrium, "a" silane, combinations(s) of these components may be used in the present invention. As used herein, "plurality" means two or more.

As used herein, "including" and similar terms means "including but not limited to".

When referring to any numerical range of values, such ranges are understood to include each and every number and/or fraction between the stated range minimum and maximum.

"molecular weight" as used herein refers to the weight average molecular weight (M) as determined by gel permeation chromatography_w)。

The term "cure" as used herein refers to a coating in which any crosslinkable components of the composition are at least partially crosslinked. In certain embodiments, the cross-link density (i.e., degree of cross-linking) of the cross-linkable component is from 5% to 100%, such as from 35% to 85%, or in some cases, from 50% to 85% of full cross-linking. It will be understood by those skilled in the art that the presence and extent of crosslinking, i.e., crosslink density, can be determined by various methods, such as Dynamic Mechanical Thermal Analysis (DMTA) under nitrogen using a Polymer Laboratories MK III DMTA analyzer.

Any monomer referred to herein generally refers to a monomer that is polymerizable with another polymerizable compound, such as another monomer or polymer. Unless otherwise indicated, it is to be understood that once the monomer components react with each other to form a compound, the compound will comprise a residue of the monomer components.

Electrodepositable coating compositions

The present invention relates to coating compositions comprising (i) a film-forming polymer, (ii) yttrium, and (iii) a silane that does not contain an ethylenically unsaturated double bond. In certain embodiments, the coating composition comprises an aminosilane which may or may not contain an ethylenically unsaturated double bond. In certain embodiments, when the film-forming polymer comprises reactive functional groups, the coating composition further comprises (iv) a curing agent reactive with the reactive functional groups of the film-forming polymer.

Various film-forming polymers known in the art may be used as component (i) provided that the polymer is "water dispersible". As used herein, "water dispersible" refers to a material that is suitable for dissolution, dispersion, and/or emulsification in water. The film-forming polymers used in the present invention are ionic in nature. Thus, in certain embodiments, the film-forming polymer is cationic. In other words, the film-forming polymer comprises cationic salt groups, typically prepared by neutralizing functional groups on the film-forming polymer with an acid, to enable electrodeposition of the film-forming polymer on the cathode.

Examples of film-forming polymers suitable for use in cationic electrocoat coating compositions include, but are not limited to, cationic polymers derived from polyepoxides, acrylics, polyurethanes, and/or polyesters. In certain embodiments, the film-forming polymer comprises reactive functional groups. The term "reactive functional group" as used herein refers to a hydroxyl, carboxyl, carbamate, epoxy, isocyanate, acetoacetate, amine salt, thiol, or a combination thereof. It should be noted that in certain embodiments, the film-forming polymer is a copolymer of the polymers listed in the previous sentence. In certain embodiments, the cationic polymer is obtainable by reacting a polyepoxide comprising the polymer with a cationic salt group former. As used herein, a "cationic salt group former" refers to a material that is reactive with epoxide groups and that can be acidified to form cationic salt groups before, during, or after reaction with epoxide groups. Suitable materials useful as cationic salt group formers include amines, such as primary or secondary amines that can be acidified to form amine salt groups after reaction with an epoxy group, or tertiary amines that can be acidified prior to reaction with an epoxy group and form quaternary ammonium salt groups after reaction with an epoxy group. Examples of other cationic salt group forming agents are sulfides which can be mixed with an acid prior to reaction with an epoxy group and subsequently reacted with an epoxy group to form a tertiary sulfonium salt group.

In certain embodiments, the film-forming polymer used in the present invention comprises the reaction product of an epoxy-functional compound (e.g., EPON 880) and a phenolic hydroxyl containing material, such as bisphenol a, as a polyhydric phenol. In certain embodiments, the film-forming polymers described in the previous sentence can be reacted with amines, such as aminopropyldiethanolamine (APDEA) and Dimethylaminopropylamine (DMAPA), to render the film-forming polymer water-dispersible. In certain embodiments, the ketimine can react with the backbone of the film-forming polymer to form ketimine branches that are pendant extensions from the backbone. When the polymer is dispersed in a water/acid mixture, the ketimine branches will hydrolyze and form primary amines. Thus, in certain embodiments, the electrodepositable coating compositions disclosed in U.S. Pat. nos. 5,633,297, 5,820,987, and/or 5,936,012 can be used with the present invention.

Various corrosion inhibitors can be used as component (ii) in the present invention. Suitable corrosion inhibitors include, but are not limited to, rare earth metals, bismuth, copper, zinc, silver, zirconium, or combinations thereof. In certain embodiments, yttrium compounds may be used as corrosion inhibitors. Various yttrium compounds can be used as component (ii) in the present invention. For example, the yttrium compound can include, but is not limited to, yttrium formate, yttrium acetate, yttrium lactate, yttrium sulfamate, yttrium methanesulfonate, or a combination thereof. In certain embodiments, yttrium comprises ≦ 5 wt% total resin solids for the electrodepositable coating composition. In other embodiments, yttrium comprises 0.15 wt.% or more total resin solids of the electrodepositable coating composition. In certain embodiments, the amount of yttrium may be any combination between the values recited in the previous sentence, inclusive of the recited values. For example, in certain embodiments, the amount of yttrium can be from 0.20 wt% to 2 wt% of the total resin solids of the electrodepositable coating composition.

In the present invention, silanes which do not contain an ethylenically unsaturated double bond are generally used as component (iii). However, in certain embodiments, aminosilanes that may or may not contain an ethylenically unsaturated double bond may be used in the present invention. As used herein, "ethylenically unsaturated double bond" refers to a carbon-carbon double bond. In certain embodiments, the silane may include functional groups such as, but not limited to, hydroxyl, carbamate, epoxy, isocyanate, amine salt, thiol, or combinations thereof. Suitable silanes that may be used in the present invention include, but are not limited to, aminosilanes, mercaptosilanes, or combinations thereof. In certain embodiments, the silane may be a mixture of an aminosilane and another substance, such as vinyltriacetoxysilane. Thus, in certain embodiments, the electrodepositable coating composition may include an ethylenically unsaturated double bond-containing silane in addition to a silane that does not include an ethylenically unsaturated double bond.

If (i) the film forming polymer comprises reactive functional groups, such as those described above, the electrodepositable coating composition may further comprise (iv) a crosslinking agent ("curing agent") reactive with the reactive functional groups of the polymer. Suitable crosslinking agents include, but are not limited to, aminoplasts, polyisocyanates (including blocked isocyanates), polyepoxides, beta-hydroxyalkylamides, polyacids, anhydrides, organometallic acid functional materials, polyamines, polyamides, cyclic carbonates, siloxanes, or combinations thereof. In certain embodiments, the curing agent may constitute from 30 wt% to 40 wt% total resin solids of the coating composition.

In certain embodiments, the electrodepositable coating composition may further comprise (v) a curing catalyst useful for catalyzing the reaction between the crosslinking agent and the reactive functional groups of the film-forming polymer. Suitable curing catalysts that may be used as component (v) include, but are not limited to, organotin compounds (e.g., dibutyltin oxide, dioctyltin oxide) and salts thereof (e.g., dibutyltin diacetate); other metal oxides (e.g., oxides of cerium, zirconium, and/or bismuth) and salts thereof (e.g., bismuth sulfamate and/or bismuth lactate), bicyclic guanidines (as disclosed in U.S. patent application No. 11/835,600), or combinations thereof.

In certain embodiments, after the electrodepositable coating composition is applied to a substrate and cured, when subjected to the PATTI ADHESION TESTING METHOD, the electrodepositable coating composition exhibits a burst pressure ADHESION value of ≧ 500 pounds per square inch (psi), such as 550(psi) to 1000 (psi). PATTI ADHESION TESTING METHOD is a two-step process. In a first step, a substrate coated with a cured electrodepositable coating composition to be tested for adhesion properties is introduced into a QCT-MB chamber (commercially available from Q-Panel Lab Products) and exposed to condensing humidity for 16 hours at a temperature of 60 ℃. The substrate was then removed and a rag was used to remove any condensate on the coated surface. The adhesion properties of the cured electrodepositable coating composition were then measured using an Elcometer pati 110 adhesion tester (commercially available from Elcometer, Inc.). The process begins by using a 3M SCOTCHWELD DP-460 binder¹/₂An inch diameter aluminum pull head (commercially available from Elcometer, Inc.) was adhered to the surface of the cured electrodepositable coating composition (the surface on which the aluminum pull head was applied should be lightly sanded and then cleaned with KIMWIPES followed by water and then an isopropyl alcohol wet wipe). The piston of the Elcometer pati 110 adhesion tester was attached to the aluminum slider head and a pulling force was applied to the head using the adhesion tester. The pulling force is increased until adhesion failure of the cured electrodepositable coating composition is achieved. The value of the force required to cause adhesive failure ("burst pressure adhesion value") can then be calculated using a suitable conversion chart provided by the Elcometer pati 110 adhesion tester. As used herein, a "burst pressure adhesion value" measured in pounds per square inch (psi) is the amount of force required to cause the coating to lose adhesion to the substrate.

In certain embodiments, when the electrodepositable coating composition described herein is compared to an electrodepositable coating composition that does not comprise a silane and a corrosion inhibitor (a conventional electrodepositable coating composition), the burst pressure of the electrodepositable coating composition will exceed the burst pressure of the conventional electrodepositable coating composition by greater than or equal to 100 pounds per square inch (psi) when subjected to the PATTI ADHESION TESTING METHOD.

The electrodepositable coating compositions disclosed herein are typically provided as two components: (1) primary carrier ("virgin resin stock") and (2) ground carrier ("pigment paste"). In general, (1) the primary carrier comprises (a) a film-forming polymer ("active hydrogen-containing ionic salt group-containing resin"), (b) a crosslinker, and (c) any additional water-dispersible uncolored components (e.g., catalyst, hindered amine light stabilizer). In general, (2) the grind vehicle comprises (d) one or more pigments (e.g., titanium dioxide, carbon black), (e) a water-dispersible grind resin that may be the same or different from the film-forming polymer, and optionally (f) additives such as catalysts, antioxidants, biocides, defoamers, surfactants, wetting agents, dispersing aids, clays, hindered amine light stabilizers, UV light absorbers and stabilizers, or combinations thereof. An electrodeposition bath comprising the electrodepositable coating composition of the present invention can be prepared by dispersing components (1) and (2) in an aqueous medium comprising water and typically a coalescing solvent. The (ii) yttrium and/or (iii) silane used in the electrodepositable coating composition of the present invention may be incorporated into the primary carrier, the grind carrier, or post-added to the bath prepared from components (1) and (2). Alternatively, components (1) and (2) may also be provided as a single component.

Substrate with a coating system

The electrodepositable coating compositions described herein may be applied alone or as part of a coating system that can be deposited on a large number of different substrates. The coating system typically includes a number of coating layers. A coating is typically formed when the coating composition deposited on the substrate is sufficiently cured by methods known in the art, such as by heating.

Suitable substrates that can be coated with the electrodepositable coating composition of the present invention include, but are not limited to, metal substrates, metal alloy substrates, and/or metallized substrates, such as nickel-plated plastic. In certain embodiments, the metal or metal alloy may be aluminum and/or steel. For example, the steel substrate may be cold rolled steel, electro galvanized steel, and hot dip galvanized steel. Further, in certain embodiments, the substrate may comprise a portion of a vehicle such as a body (e.g., without limitation, a door, body panel, trunk lid, roof panel, hood, and/or roof) and/or a vehicle frame. As used herein, "vehicle" or variations thereof include, but are not limited to, commercial, and military land vehicles such as cars, motorcycles, and trucks. It is also understood that in certain embodiments, the substrate may be pretreated with a pretreatment solution, such as a zinc phosphate solution described in U.S. Pat. nos. 4,793,867 and 5,588,989. Additionally, in other embodiments, the substrate is not pretreated with a pretreatment solution prior to coating the substrate with the coating composition described herein.

In certain embodiments, the electrodepositable coating composition of the present invention is applied to a bare (i.e., not previously treated) substrate. However, in certain embodiments, the electrodepositable coating composition of the present invention may be applied to a substrate that has been previously treated. After the electrodepositable coating composition is cured, a primer-surfacer coating composition is applied to at least a portion of the electrodepositable coating composition. The primer-surfacer coating composition is typically applied to the electrodepositable coating layer and cured prior to applying a subsequent coating composition onto the primer-surfacer coating composition.

The primer-surfacer layer resulting from the primer-surfacer coating composition serves to enhance the chip resistance of the coating system as well as aid in the appearance of subsequently applied coatings (e.g., color imparting coating compositions and/or substantially clear coating compositions). As used herein, "primer-surfacer" refers to a primer composition used under a subsequently applied coating composition and includes such materials as are generally known in the art of organic coating compositions as thermoplastic and/or crosslinked (e.g., thermosetting) film-forming resins. Suitable primer and primer-surfacer coating compositions include spray-applied primers as known to those skilled in the art. Examples of suitable primers include several available from PPG Industries, Inc., Pittsburgh, Pa., DPX-1791, DPX-1804, DSPX-1537, GPXH-5379, OPP-2645, PCV-70118, and 1177-. Another suitable primer-surfacer coating composition that can be used in the present invention is the primer-surfacer described in U.S. patent application No. 11/773,482, which is incorporated herein by reference in its entirety.

It should be noted that in certain embodiments, the primer-surfacer coating composition is not used in the coating system. Thus, the color-imparting primer composition can be applied directly to the cured electrodepositable coating composition.

In certain embodiments, a color-imparting coating composition (hereinafter "basecoat") is deposited over at least a portion of the primer surfacer coating (if present). Any primer coating composition known in the art may be used in the present invention. It should be noted that these basecoat coating compositions typically contain a colorant.

In certain embodiments, a substantially clear coating composition (hereinafter "clearcoat") is deposited over at least a portion of the basecoat. As used herein, a "substantially transparent" coating is substantially transparent and not opaque. In certain embodiments, the substantially clear coating composition may include a colorant, but in an amount that does not render the clear coating composition opaque (not substantially clear) upon curing. Any clearcoat coating composition known in the art may be used in the present invention. For example, clearcoat coating compositions described in U.S. Pat. Nos. 5,989,642, 6,245,855, 6,387,519, and 7,005,472, which are incorporated herein by reference in their entirety, can be used in the coating system. In certain embodiments, the substantially clear coating composition can further comprise particles, such as silica particulates, dispersed in the clearcoat coating composition (e.g., on the clearcoat coating composition surface after curing).

One or more of the coating compositions described herein may comprise colorants and/or other optional materials known in the art of formulating surface coatings. The term "colorant" as used herein refers to any substance that imparts color and/or other opacity and/or other visual effect to the composition. The colorant may be added to the coating in any suitable form, such as discrete particles, dispersions, solutions, and/or flakes (e.g., aluminum flakes). A single colorant or a mixture of two or more colorants can be used in the coating compositions described herein.

Examples of colorants include pigments, dyes, and tints, such as those used in the coatings industry and/or listed in the Dry Color Manufacturers Association (DCMA), as well as special effect compositions. The colorant may, for example, comprise a finely divided solid powder that is insoluble but wettable under the conditions of use. The colorant may be organic or inorganic and may be aggregated or unaggregated. The colorants can be incorporated into the coating by using a grind vehicle, such as an acrylic grind vehicle, the use of which is well known to those skilled in the art.

Examples of pigments and/or pigment compositions include, but are not limited to, carbazole bisOxazine crude pigments, azo, monoazo, disazo, naphthol AS, salt forms (lakes), benzimidazolones, condensates, metal complexes, isoindolinones, isoindolines and polycyclic phthalocyanines, quinacridones, perylenes, perinones, diketopyrrolopyrroles, thioindigo, anthraquinones, indanthrones, anthrapyrimidines, flavanthrones, pyranthrones, anthanthrones, dianthraquinones, lawsonitrons, lakemidines, laOxazines, triarylcarbonium, quinophthalone pigments, diketopyrrolopyrrole red ("DPPBO red"), titanium dioxide, carbon black, and mixtures thereof. The terms "pigment" and "colored filler" are used interchangeably.

Examples of dyes include, but are not limited to, those that are solvent and/or aqueous based, such as phthalocyangreen or phthalocyanblue, iron oxide, bismuth vanadate, anthraquinone, perylene, aluminum, and quinacridone.

Examples of tints include, but are not limited to, pigments dispersed in an aqueous-based or water-miscible vehicle, such as AQUA-CHEM 896 commercially available from Degussa, inc, charismacolor and maxiner-INDUSTRIAL color commercially available from AccurateDispersions division of Eastman Chemical, inc.

As noted above, the colorant can be in the form of a dispersion, including but not limited to in the form of a nanoparticle dispersion. Nanoparticle dispersions can include one or more highly dispersed nanoparticle colorants and/or colorant particles that produce a desired visible color and/or opacity and/or visual effect. The nanoparticle dispersion may include a colorant such as a pigment or dye having a particle size of less than 150nm, for example less than 70nm, or less than 30 nm. Nanoparticles can be produced by milling a starting organic or inorganic pigment with milling media having a particle size of less than 0.5 mm. Examples of nanoparticle dispersions and methods for their preparation are described in U.S. Pat. No. 6,875,800, which is incorporated herein by reference. Nanoparticle dispersions can also be produced by crystallization, precipitation, gas phase condensation and chemical attrition (i.e., partial dissolution). To minimize re-agglomeration of the nanoparticles in the coating, a dispersion of resin-coated nanoparticles may be used. As used herein, a "dispersion of resin-coated nanoparticles" refers to a continuous phase in which are dispersed discrete "composite particles" comprising nanoparticles and a resin coating on the nanoparticles. Examples of dispersions of resin-coated nanoparticles and methods for their preparation are described in U.S. patent publication 2005-0287348, filed 24.6.2004, U.S. provisional application No. 60/482,167, filed 24.6.2003, and U.S. patent application No. 11/337,062, filed 20.1.2006, which are incorporated herein by reference.

Examples of special effect compositions that may be used include pigments and/or compositions that produce one or more appearance effects such as reflectance, pearlescence, metallic sheen, phosphorescence, fluorescence, photochromism, photosensitivity, thermochromism, goniochromism (goniochromism), and/or color change. Other special effect compositions may provide other perceptible properties, such as opacity or texture. In a non-limiting embodiment, the special effect composition can produce a color shift such that the color of the coating changes when the coating is viewed at different angles. Examples of color effect compositions are described in U.S. Pat. No. 6,894,086, which is incorporated herein by reference. Other color effect compositions can include transparent coated mica and/or synthetic mica, coated silica, coated alumina, transparent liquid crystal pigments, liquid crystal coatings, and/or any composition in which interference is caused by refractive index differences within the material and not due to refractive index differences between the surface of the material and the air.

In certain non-limiting embodiments, photosensitive compositions and/or photochromic compositions that can reversibly change their color when exposed to one or more light sources can be used in the coating compositions described herein. Photochromic and/or photosensitive compositions can be activated by exposure to radiation of a particular wavelength. When the composition is excited, the molecular structure changes and the changed structure exhibits a new color that is different from the original color of the composition. When exposure to radiation is removed, the photochromic and/or photosensitive composition can return to a quiescent state, wherein the original color of the composition is restored. In one non-limiting embodiment, the photochromic and/or photosensitive composition can be colorless in a non-excited state and exhibit color in an excited state. Complete color change can occur within milliseconds to minutes, such as 20 seconds to 60 seconds. Examples of photochromic and/or photosensitive compositions include photochromic dyes.

In non-limiting embodiments, the photosensitive composition and/or photochromic composition can be associated and/or at least partially bound to the polymer and/or polymeric material of the polymerizable component, such as by covalent bonds. Photosensitive compositions and/or photochromic compositions that are associated and/or at least partially bound to polymers and/or polymerizable components according to non-limiting embodiments of the present invention have minimal migration from the coating, as compared to certain coatings in which the photosensitive composition can migrate from the coating and crystallize into the substrate. Examples of photosensitive and/or photochromic compositions and methods for their preparation are described in U.S. application serial No. 10/892,919 filed on 7, 16, 2004.

In general, the colorant can be present in any amount sufficient to impart the desired visual and/or color effect. The colorant may constitute 1 to 65 weight percent, such as 3 to 40 weight percent or 5 to 35 weight percent, of the composition of the present invention, where weight percentages are based on the total weight of the composition.

The coating composition may contain other optional materials well known in the art of formulating surface coatings, such as plasticizers, antioxidants, hindered amine light stabilizers, UV light absorbers and stabilizers, surfactants, flow control agents, thixotropic agents such as bentonite clay, pigments, fillers, organic cosolvents, catalysts, including phosphonic acids, and other conventional adjuvants.

In addition to the materials described above, the coating composition may also include an organic solvent. Suitable organic solvents that may be used in the coating composition include those listed in the preceding paragraph as well as butyl acetate, xylene, methyl ethyl ketone, or combinations thereof.

It will be further understood that the one or more coating compositions forming the various coatings described herein may be "one-component" ("1K"), "two-component" ("2K"), or even a multi-component composition. A 1K composition is to be understood as meaning a composition in which all coating components are kept in the same container after preparation, during storage, etc. A 2K composition or a multi-component composition is to be understood as meaning a composition in which the individual components are kept separately until just before application. The 1K or 2K coating composition can be applied to a substrate and cured by any conventional method, such as heat, pressurized air, and the like.

The coating compositions forming the various coatings described herein can be deposited or applied to a substrate using any technique known in the art. For example, the coating composition may be applied to the substrate by any of a variety of methods including, but not limited to, spraying, brushing, dipping, and/or rolling, among other methods. When multiple coating compositions are applied to a substrate, it should be noted that one coating composition may be applied to at least a portion of the primer coating composition after the primer coating composition has been cured or before the primer coating composition is to be cured. If the coating composition is applied to an as yet uncured primer coating composition, both coating compositions may be cured simultaneously.

The coating composition may be cured using any technique known in the art, such as, but not limited to, thermal energy, infrared, ionizing or actinic radiation, or by any combination thereof. In certain embodiments, the curing operation may be conducted at a temperature of ≧ 10 ℃. In other embodiments, the curing operation may be conducted at a temperature of 246 ℃ or less. In certain embodiments, the curing operation may be conducted at a temperature range of any combination of the values recited in the preceding sentence, inclusive of the recited values. For example, the curing operation may be carried out at a temperature of from 120 ℃ to 150 ℃. However, it should be noted that lower or higher temperatures may be used as desired to activate the curing mechanism.

In certain embodiments, one or more of the coating compositions described herein are low temperature, moisture curable coating compositions. The term "low temperature, moisture curable" as used herein means that the coating composition is capable of curing in the presence of ambient air having a relative humidity of from 10% to 100%, such as from 25% to 80%, and a temperature of from-10 ℃ to 120 ℃, such as from 5 ℃ to 80 ℃, in some cases from 10 ℃ to 60 ℃, and in other cases from 15 ℃ to 40 ℃ after application to a substrate.

The dry film thickness of the coatings described herein can range from 0.1 microns to 500 microns. In other embodiments, the dry film thickness can be 125 microns or less, such as 80 microns or less. For example, the dry film thickness may be 15 microns to 60 microns.

While specific embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the invention which is to be given the full breadth of the claims appended and any and all equivalents thereof.

Examples

Example A

Cationic resin A: the cationic resin was prepared from a mixture of the following ingredients:

1039.8g of crosslinker 1 (see description below), 55.0g of Macol98B (bisphenol A-6 ethylene oxide polyol available from BASF Corporation), 69.6g of diethylene glycol monobutyl ether formal, 528.7g of Epon828 (epoxy resin available from Resolution Performance Products), 203.9g of bisphenol A, and 0.18g of Tetronic 150R1 available from BASF Corporation were charged into a batch autoclave equipped with a stirrer, temperature measuring probe, N.sub.₂Blanket and Dean-Stark trap in a 4-neck round bottom flask. The mixture was heated to 75 ℃ and 34.7g of diethanolamine was added. The mixture exothermed to about 80 ℃ and was held for 30 minutes after diethanolamine was added. 80.3g of aminopropyldiethanolamine were added, the temperature was adjusted to 132 ℃ and the mixture was subsequently held at this temperature for 2 hours while approximately 30g of solvent were collected in the Dean-Stark trap. 1680g of this mixture was poured into a mixture of 30.5g sulfamic acid, 1181g deionized water, 1.15g lactic acid (88%), and 66.3g additive resin 1 (described below). The mixture was stirred for 30 minutes. 1183g of deionized water was added and mixed well. 1000g of deionized water was added and mixed thoroughly. The solvent and water were removed by vacuum distillation and the solids of the resulting aqueous dispersion were adjusted to 39%. The methylisobutylketone content of the dispersion was less than 0.2%.

Crosslinker 1 was prepared by adding 1320g (10eq.) Desmodur LS 2096 (MDI type isocyanate available from Bayer corporation) to a mixture of 92g ethanol, 456g propylene glycol, 740g Macol98B (see above) and 486g diethylene glycol monobutyl ether formal and 93g methyl isobutyl ketone. 68g of methyl isobutyl ketone were used as rinsing agent for the isocyanate. The temperature was raised to 115 ℃ and the mixture was held at this temperature until the infrared spectrum showed no isocyanate.

Description of additive resin 1

1	MAZEEN 355701	1423.49
			2	Acetic acid	15.12
3	Dibutyl tin dilaurate	1.52
			4	Toluene diisocyanate 80/20	200.50
5	Sulfamic acid	79.73
			6	Deionized water	1623.68
7	Deionized water	766.89

¹Amine functional diols available from BASF Corporation with an amine equivalent weight of 1131.

Charging materials 1 and 2 equipped with a stirrer, a temperature measuring probe and N₂A 4-neck round bottom flask of the overlay and mixed for 10 minutes. Charge 3 was added, followed by Charge 4 in about 1 hour, allowing the reaction mixture to exotherm to a maximum temperature of 100 ℃. The mixture was then maintained at 100 ℃ until the infrared spectrum showed no isocyanate (about 1 hour). 1395g of the reaction mixture was poured into the mixture of materials 5 and 6 and mixed for 1 hour. Charge 7 was then added over about 1 hour and mixed for about 1 hour. The solids content of the resulting aqueous solution was about 36%.

Example B

Cationic resin B: the cationic resin was prepared from a mixture of the following ingredients:

¹available from BASF corp as Mazon 1651

²Epoxy resins available from Hexion Specialty Chemicals

³Available from BASF Corp

⁴Available from Air Products Corp

⁵Reverse reaction of 10 equivalents Desmodur LS 2096(Bayer Corp.) with 2 moles of ethanol, 7 moles of propylene glycol and 1 mole of Macol98B (bisphenol ethylene oxide adduct with molecular weight 500, BASF Corp.)The reaction product is a solution

The procedure is as follows: the materials 1, 2, 3 and 4 are charged into a reactor equipped with a stirrer, a temperature measuring probe, N₂The blanket and Dean-Stark trap were placed in a 4-neck round bottom flask and heated to 70 ℃ and mixed for 15 minutes. The heating was stopped and materials 5,6 and 7 were added (mixed). The reaction mixture exothermed to a maximum of 176 ℃ after about 10 minutes. Materials 8 and 9 were added slowly (mixed) 15 minutes after the peak exotherm temperature and the mixture was cooled from the peak exotherm temperature to 145 ℃ and held at this temperature for a total of 2 hours. Then materials 10 and 11 were added and the mixture was adjusted to 110 ℃. 2040g of the reaction mixture was poured, with vigorous stirring, into a solution of the materials 12, 13 and 14, this solution having been prepared beforehand by heating and stirring a mixture of 12, 13 and 14 to 60 ℃ for 30 minutes, then cooling to 50 ℃. The resin dispersion was allowed to mix for about 1 hour. Material 15 was added slowly with stirring. The final aqueous dispersion measured a solids content of 20%.

Example C

Grinding resin: this example describes the preparation of a quaternary ammonium salt-containing pigment-grinding resin. Example C-1 describes the preparation of an amine acid salt quaternizing agent and example C-2 describes the preparation of an epoxy group containing polymer which is subsequently quaternized with an amine acid salt of example C-1.

C-1 an amine acid salt quaternizing agent was prepared using the following procedure:

material 1 was charged to a suitably equipped 5 liter flask. Material 2 was then charged with gentle stirring over 1.5 hours, followed by a rinse of material 3. During this addition, the reaction mixture was allowed to exotherm to a temperature of about 89 ℃ and held at this temperature for about 1 hour until the isocyanate was fully reacted as determined by infrared spectroscopy. At this point, material 4 was added over 25 minutes, followed by material 5. The reaction temperature was maintained at about 80 ℃ for about 6 hours until a resting acid number of 70.6 was obtained.

C-2A quaternary ammonium salt group-containing polymer was prepared using the following procedure.

Material 1 was charged into a suitably equipped 5 liter flask with gentle stirring. Material 2 is then added followed by material 3 and material 4. The reaction mixture was heated to about 140 ℃, allowed to exotherm to about 180 ℃, then cooled to about 160 ℃ and held at this temperature for about 1 hour. At this time, the epoxy equivalent of the polymer product was 982.9. The reaction mixture was then cooled to a temperature of about 130 c at which time material 5 was added and the temperature was reduced to about 95 c-100 c, followed by the addition of the amine-acid quaternizing agent for materials 6, 6-1 over a period of 15 minutes, followed by the addition of about 1428.1 parts by weight deionized water. The reaction temperature was maintained at about 80 ℃ for about 6 hours until the acid number of the reaction product was below 1.0. The obtained quaternary ammonium salt group-containing pigment grinding resin was further refined with about 334.7 parts by weight of butyl carbitol formal solvent.

Example D

Pigment paste: this example describes the preparation of a pigment paste suitable for use in the electrodeposition bath composition of the present invention.

The pigment paste was prepared with the following ingredients:

¹prepared from a mixture of: 632g of the quaternary ammonium salt group-containing grinding resin of example C; 92g of deionized water; 19g of n-butoxypropanol; and 368g STANN BO (di-n-butyl tin oxide catalyst available from Sankyo Organic Chemicals co., ltd.). The above ingredients were added in the order shown with high shear stirring. After the components were fully blended, the pigment paste was transferred to a vertical sander and ground to a Hegman value of about 7.26.

The above ingredients were first dispersed with a high speed cowles blade (cowles blade) for 30 minutes and then milled in a planimel mill with 1.0-1.6mm Zircoa medium for 1 hour or until the Hegman value reached about 7.

Example E

Resin blend 1: this example describes the preparation of a masterbatch of resin blends for use in paints 1, 3 and 5 below.

Weight (g)	Material
		2349.0	Cationic resin from example A
246.9	Toughening agent1
		32.4	Plasticizer2
12.0	Propylene glycol monomethyl ether from BASF corp
		6.0	Ethylene glycol monohexyl ether from BASF Corp
120.0	Flow additive3
		233.7	Deionized water

¹711g of DER732 (aliphatic epoxy resin from Dow Chemical Co.) and 164.5g of bisphenol A were charged into a suitably equipped 3 liter round bottom flask. The mixture was heated to 130 ℃ and 1.65g of benzyldimethylamine were added. The reaction mixture was held at 135 ℃ until the epoxy equivalent weight of the mixture was 1232. 78.8g of butyl carbitol formal (available from BASFCorp. as Mazon 1651) was added and the mixture was cooled to 95 ℃. 184.7g Jeffamine D400 (a polyoxypropylene diamine available from Huntsman Corp.) was added and the reaction was held at 95 ℃ until the Gardner-Holdt viscosity of the resin sample diluted at 50/50 in methoxypropanol was "HJ". A mixture of 19.1g Epon828 and 3.4g butyl carbitol formal was added and the mixture was held until the Gardner-Holdt viscosity of the resin sample diluted at 50/50 in methoxypropanol was "Q-". 988.6g of this resin were poured into a mixture of 1242.13g of deionized water and 30.2g of sulfamic acid and mixed for 30 minutes. 614.8g of deionized water was then added and mixed thoroughly. The measured solids content of the final aqueous dispersion was 35.8%.

²The reaction product of 2 moles diethylene glycol monobutyl ether and 1 mole formaldehyde, 98% active ingredient, was prepared as described in McCollum et al, U.S. patent No. 4,891,111.

³Prepared by mixing a cationic polyepoxide amine reaction product and a polyepoxide crosslinking agent as described in U.S. patent No. 5,096,556 to corigan et al.

Example F

Resin blend 2: this example describes a preparation of a resin blend used in the following paint 7:

weight (g)	Material
		1820.0	Cationic resin from example B
67.1	Toughening agent described in example E
		11.7	The plasticizer described in example E
4.3	Propylene glycol monomethyl ether from BASF corp
		2.2	Ethylene glycol monohexyl ether from BASF Corp
43.5	Flow additive described in example E
		103.5	Deionized water

Example AA

Yttrium solution: this example describes a preparation of a soluble yttrium solution for use in the electrodeposition bath compositions of paints 2, 4 and 6 in table 1. The soluble yttrium solution was prepared from the following mixture:

weight (g)	Material
		112.9	Yttrium trioxide
485.0	Deionized water
		291.3	Sulfamic acid

To a suitably equipped 5 liter flask was added sulfamic acid and water and stirred for 20 minutes. The solution was heated to 98 ℃ and then held until a clear solution was obtained. Held for at least 2 hours. The solution was allowed to cool to below 50 ℃.

Example BB

Silane solution 1: this example describes a preparation of an aminosilane solution suitable for use in the electrodeposition bath compositions of paints 3,4 and 7 in table 1.

The ingredients were combined and allowed to mix for 20 minutes. After 20 minutes, 88% lactic acid was added until the pH reached about 5.5.

Example CC

Silane solution 2: this example describes the preparation of a mixture of bis (trimethoxysilylpropyl) amine and vinyltriacetoxysilane suitable for use in the electrodeposition bath compositions for paints 5 and 6.

The ingredients were combined and allowed to mix for 20 minutes.

The following table provides examples of the preparation of electrodeposition bath compositions of the present invention:

table 1:

paints 1, 3 and 5 were prepared by adding the cationic resin blend from example E to a 1 gallon plastic container. The pigment paste was then diluted with about 200 grams of deionized water prior to addition to the resin blend. In the above table, the silane solution is shown to be diluted with about 20g of deionized water prior to addition. The remaining deionized water was then added to the vessel. The final bath solids was about 21.5% with a pigment to binder ratio of about 0.14. The test bath was ultrafiltered 30% and filled with fresh deionized water only. After ultrafiltration, paints 2, 4 and 6 were prepared by subsequently adding deionized water, yttrium and/or silane in the amounts listed above to paints 1, 3 and 5, respectively.

Paint 7 was prepared by adding the cationic resin blend from example F to a 1 gallon plastic container. The pigment paste was then diluted with about 50g of deionized water and added to the resin blend. The silane solution from example BB was diluted with the remaining deionized water and added to the mixture.

The above paint compositions of examples (2) to (7) were compared with example (1). The test substrates were 4 '. times.6' ACT CRS and EZG plaques purged with alkaline cleaner. The panels were not pretreated prior to electrocoating. These plates are available from ACT Laboratories, Hillside, Michigan.

Each of the electrodeposition bath compositions of examples 1-7 was electrodeposited on non-phosphated cold rolled and electrogalvanized steel sheets. The conditions for each cationic electrodeposition were as follows: 20-70 columns, 150-200 volts, produced cured films with thicknesses of 0.8-1.0 mils at 92F. The coated substrate was cured in an electric oven at 350 ° F for 20 minutes.

Each coated untreated steel test panel was subjected to adhesion testing using an Elcometer pati 110 adhesion tester. The results reported in the following table are for the test panels that have been subjected to condensation humidity for 16 hours.

Table 2:

PATTI adhesion (post QCT) burst pressure (psi)

The data reported in table 2 illustrates the improvement in post-QCT pati adhesion when silane and soluble yttrium salt are present in the electrodeposition bath of the present invention.

Claims (26)

1. An electrodepositable coating composition comprising (i) a film-forming polymer, (ii) a corrosion inhibitor, and (iii) a silane that does not contain an ethylenically unsaturated double bond.

2. The electrodepositable coating composition according to claim 1, wherein the corrosion inhibitor comprises a rare earth metal, a lanthanide element, or combinations thereof.

3. The electrodepositable coating composition according to claim 2, wherein the corrosion inhibitor is yttrium.

4. The electrodepositable coating composition according to claim 1, wherein (ii) the corrosion inhibitor comprises less than or equal to 5 weight percent of the total resin solids of the electrodepositable coating composition.

5. The electrodepositable coating composition according to claim 1, wherein the (iii) silane comprises ≦ 5 wt.% of the total resin solids of the electrodepositable coating composition.

6. The electrodepositable coating composition according to claim 1, wherein the electrodepositable coating composition further comprises a silane containing an ethylenically unsaturated double bond.

7. The electrodepositable coating composition according to claim 1, wherein the silane contains a functional group, and wherein the functional group comprises an amino group, an epoxy group, a thiol, or a combination thereof.

8. The electrodepositable coating composition according to claim 1, wherein the electrodepositable coating composition further comprises bismuth, copper, zinc, silver, zirconium, or combinations thereof.

9. The electrodepositable coating composition according to claim 1, wherein (i) the film-forming polymer comprises reactive functional groups and wherein the electrodepositable coating composition further comprises (iv) a crosslinking agent reactive with the reactive functional groups of component (i).

10. The electrodepositable coating composition according to claim 9, wherein the electrodepositable coating composition further comprises a curing catalyst.

11. The electrodepositable coating composition according to claim 10, wherein the curing catalyst comprises an organotin compound, bicyclic guanidine, or a combination thereof.

12. A substrate coated with the electrodepositable coating composition of claim 1.

13. The substrate according to claim 12, wherein the substrate is not pretreated with a phosphate or zirconium pretreatment solution prior to coating the substrate with the electrodepositable coating composition.

14. The substrate according to claim 12, wherein the substrate is pretreated with a phosphate or zirconium pretreatment solution prior to coating the substrate with the electrodepositable coating composition.

15. The substrate of claim 12, wherein the substrate comprises steel, galvanized steel, or aluminum.

16. An electrodepositable coating composition consisting essentially of (i) a film-forming polymer comprising reactive functional groups, (ii) yttrium, (iii) a silane that does not contain ethylenically unsaturated double bonds; (iv) a crosslinker reactive with the reactive functional groups of the film-forming polymer; and (v) a catalyst.

17. The electrodepositable coating composition according to claim 16, wherein after application to a substrate and curing, when subjected to the PATTI ADHESION TEST, exhibits a burst pressure that is at least 100psi greater than the burst pressure of an electrodepositable coating composition that does not comprise (ii) yttrium and (iii) silane.

18. The electrodepositable coating composition according to claim 16, wherein the silane comprises a functional group, and wherein the functional group comprises an amino group, an epoxy group, a thiol, or a combination thereof.

19. The electrodepositable coating composition according to claim 1, wherein the silane is an aminosilane.

20. An electrodepositable coating composition comprising (i) a film-forming polymer, (ii) yttrium, and (iii) an aminosilane.

21. The electrodepositable coating composition according to claim 20, wherein the aminosilane comprises a functional group.

22. The electrodepositable coating composition according to claim 20, wherein after application to a substrate and after curing, exhibits a burst pressure, when subjected to the PATTI ADHESION TEST, that is at least 100psi greater than the burst pressure of an electrodepositable coating composition that does not comprise (ii) yttrium and the (iii) aminosilane.

23. The electrodepositable coating composition according to claim 20, wherein (i) the film-forming polymer comprises reactive functional groups and wherein the electrodepositable coating composition further comprises (iv) a crosslinking agent reactive with the reactive functional groups of component (i).

24. The electrodepositable coating composition according to claim 23, wherein the electrodepositable coating composition further comprises (v) a catalyst.

25. The electrodepositable coating composition according to claim 24, wherein the catalyst comprises dibutyltin oxide, bicyclic guanidine, or a combination thereof.

26. A substrate coated with the electrodepositable coating composition of claim 20.