WO2016210237A1

WO2016210237A1 - Polyaspartic ester based coatings for metal surfaces

Info

Publication number: WO2016210237A1
Application number: PCT/US2016/039190
Authority: WO
Inventors: Kathy Allen; Irene YANO; Emery Yuhas
Original assignee: Covestro Llc
Priority date: 2015-06-26
Filing date: 2016-06-24
Publication date: 2016-12-29

Abstract

The present invention provides a method of coating a surface of a substrate comprising pretreating the substrate with a pretreatment composition, curing the pretreatment composition, applying over the pretreatment composition a coating composition comprising an aliphatic polyisocyanate and an isocyanate reactive compound comprising at least a polyaspartic acid ester and curing the coating composition, wherein the coated substrate has a mean corrosion creepage as measured by ASTM D 1654 is not greater than 3 mm. Also provided is a composite comprising a substrate comprising at least one member selected from the group consisting of metals, plastics, ceramics, glass, and natural materials, a layer of pretreatment composition comprising at least one of iron phosphate, zinc phosphate, zirconium, titanium, vanadium and hafnium, and a layer of coating composition comprising a polyisocyanate and an aliphatic isocyanate reactive compound comprising at least a polyaspartic acid ester. A single layer of the polyaspartic ester based coating compositions cured at ambient temperature eliminates the need for a primer layer, primer oven, and topcoat oven while providing corrosion resistance on pretreated substrates. The inventive method is particularly suitable for line production processes.

Description

POLYASPARTIC ESTER BASED COATINGS FOR METAL SURFACES

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No. 62/185,241 filed June 26, 2015, the entire contents of which are incorporated herein by reference.

FIELD OF THE INVENTION

[0001] The present invention relates in general to coatings and more specifically to the application of polyaspartic ester based coating compositions to metal surfaces.

BACKGROUND OF THE INVENTION

[0002] The agricultural and construction equipment ("ACE") industry is moving toward more environmentally friendly pretreatments for steel. Chrome sealers have been replaced by non-chrome containing sealers. Iron phosphate pretreatments are being replaced by zirconium-based pretreatments. Manufacturers in the ACE industry have indicated a preference for zirconium-based pretreatment. It is ambient cure which provides a cost savings to the original equipment manufacturer ("OEM"). However, because standard two-component, solvent borne polyurethanes do not exhibit the same performance with zirconium-based pretreatment, OEMs have been slow to switch.

[0003] Thus, a need continues to exist in the art for a way to provide better performance over chrome-free sealers and better performance over zirconium-based pretreatments while maintaining corrosion resistance.

SUMMARY OF THE INVENTION

[0004] In various embodiments, the present invention provides a method of coating a surface of a substrate comprising: pretreating the substrate with a pretreatment composition, curing the pretreatment composition, applying over the pretreatment composition a coating composition comprising an aliphatic polyisocyanate and an isocyanate reactive compound containing at least a polyaspartic acid ester and curing the coating composition.

[0005] Certain embodiments of the invention provide a composite comprising a substrate comprising at least one member selected from the group consisting of metals, plastics, ceramics, glass, and natural materials, a layer of pretreatment composition comprising at least one of iron phosphate, zinc phosphate, zirconium, titanium, vanadium and hafnium, and a layer of coating composition comprising an aliphatic polyisocyanate and an isocyanate reactive compound containing at least a polyaspartic acid ester.

[0006] Surprisingly, polyaspartic ester based coating compositions demonstrate better performance over chrome-free sealers and better performance over zirconium-based pretreatment. A single layer of polyaspartic ester containing coating compositions eliminates the need for a primer layer, primer oven, and topcoat oven while providing corrosion resistance on pretreated substrates.

[0007] These and other advantages and benefits of the present invention will be apparent from the Detailed Description of the Invention herein below. It is understood that the invention disclosed and described in this specification is not limited to the embodiments summarized in this Summary.

BRIEF DESCRIPTION OF THE FIGURES

[0008] The present invention will now be described for purposes of illustration and not limitation in conjunction with the figures, wherein:

[0009] FIG. 1 is a schematic of a multiple stage zirconium dipping pretreatment process useful in certain embodiments of the invention; and

[0010] FIGS. 2A, 2B and 2C depict a comparison of three

pretreatments after salt spray (fog) testing for 500 hours according to ASTM- D-1654: iron phosphate (FIG. 2A), ZIRCOBOND (zirconium based, FIG. 2B) and NPLF (zirconium based, FIG. 2C).

DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention will now be described for purposes of illustration and not limitation. Except in the operating examples, or where otherwise indicated, all numbers expressing quantities, percentages, and so forth in the specification are to be understood as being modified in all instances by the term "about."

[0012] Any numerical range recited in this specification is intended to include all sub-ranges of the same numerical precision subsumed within the recited range. For example, a range of "1.0 to 10.0" is intended to include all sub-ranges between (and including) the recited minimum value of 1.0 and the recited maximum value of 10.0, that is, having a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 0.0, such as, for example, 2.4 to 7.6. Any maximum numerical limitation recited in this specification is intended to include all lower numerical limitations subsumed therein and any minimum numerical limitation recited in this specification is intended to include all higher numerical limitations subsumed therein. Accordingly, Applicants reserve the right to amend this specification, including the claims, to expressly recite any sub-range subsumed within the ranges expressly recited herein. All such ranges are intended to be inherently described in this specification such that amending to expressly recite any such sub-ranges would comply with the requirements of 35 U.S.C. §112(a), and 35 U.S.C. §132(a).

[0013] Any patent, publication, or other disclosure material identified herein is incorporated by reference into this specification in its entirety unless otherwise indicated, but only to the extent that the incorporated material does not conflict with existing definitions, statements, or other disclosure material expressly set forth in this specification. As such, and to the extent necessary, the express disclosure as set forth in this specification supersedes any conflicting material incorporated by reference herein. Any material, or portion thereof, that is said to be incorporated by reference into this specification, but which conflicts with existing

definitions, statements, or other disclosure material set forth herein, is only incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material. Applicants reserve the right to amend this specification to expressly recite any subject matter, or portion thereof, incorporated by reference herein.

[0014] Reference throughout this specification to "various non-limiting embodiments," "certain embodiments," or the like, means that a particular feature or characteristic may be included in an embodiment. Thus, use of the phrase "in various non-limiting embodiments," "in certain

embodiments," or the like, in this specification does not necessarily refer to a common embodiment, and may refer to different embodiments. Further, the particular features or characteristics may be combined in any suitable manner in one or more embodiments. Thus, the particular features or characteristics illustrated or described in connection with various or certain embodiments may be combined, in whole or in part, with the features or characteristics of one or more other embodiments without limitation. Such modifications and variations are intended to be included within the scope of the present specification.

[0015] The grammatical articles "a", "an", and "the", as used herein, are intended to include "at least one" or "one or more", unless otherwise indicated, even if "at least one" or "one or more" is used in certain instances. Thus, the articles are used in this specification to refer to one or more than one (i.e., to "at least one") of the grammatical objects of the article. By way of example, and without limitation, "a component" means one or more components, and thus, possibly, more than one component is contemplated and may be employed or used in an implementation of the described embodiments. Further, the use of a singular noun includes the plural, and the use of a plural noun includes the singular, unless the context of the usage requires otherwise.

[0016] As used herein, the term "polymer" encompasses prepolymers, oligomers and both homopolymers and copolymers; the prefix "poly" in this context referring to two or more. As used herein, the term "molecular weight", when used in reference to a polymer, refers to the number average molecular weight, unless otherwise specified.

[0017] Certain embodiments of the present invention are directed to applying coating compositions, such as two-component coating

compositions. As used herein, the term "two-component coating composition" refers to a composition comprising at least two components that are stored in separate containers because of their mutual reactivity. One component of such compositions is a hardener/crosslinker

component comprising a polyisocyanate and another component of the composition is a binder component comprising an isocyanate-reactive resin, including the polymeric polyol and polyaspartic ester described herein. The two components are generally not mixed until shortly before application of the composition to a substrate. When the two separate components are mixed and applied as a film on a substrate, the mutually reactive compounds in the two components react to crosslink and form a cured coating film.

[0018] As used herein, the term "coating composition" refers to a mixture of chemical components that will cure and form a coating when applied to a substrate. As used herein, the term "binder" refers to the component of a two-component coating composition that comprises an isocyanate-reactive resin. As used herein, the terms "hardener" and "crosslinker" are synonymous and refer to the component of a two- component coating composition that comprises a polyisocyanate.

[0019] As indicated, the coating compositions useful in the present invention comprise a polyisocyanate. As used herein, the term "polyisocyanate" refers to compounds comprising at least two unreacted isocyanate groups, such as three or more unreacted isocyanate groups.

[0020] Suitable aliphatic polyisocyanates include, for example, low molecular weight polyisocyanates having a molecular weight of 168 to 300, such as hexamethylene diisocyanate (HDI), pentamethylene diisocyanate (PDI), 2,2,4- and/or 2, 4,4-trimethyl-1 ,6-hexamethylene diisocyanate, dodecamethylene diisocyanate, 1 ,4- diisocyanatocyclohexane, 1 -isocyanato-3,3,5-trimethyl-5- isocyanatomethylcyclohexane (IPDI), 2,4'- and/or 4,4'-diisocyanato- dicyclohexyl methane, 2,4- and/or 4,4'-diisocyanato-diphenyl methane and mixtures of these isomers with their higher homologues which are obtained in known manner by the phosgenation of aniline/formaldehyde condensates, 2,4- and/or 2,6-diisocyanatotoluene and any mixtures of these compounds.

[0021] In some cases, the polyisocyanate comprises a derivative of any of the foregoing monomeric polyisocyanates, such as a derivative containing biuret groups, isocyanurate groups, urethane groups, carbodiimide groups, and/or allophanate groups.

[0022] Specific examples of suitable modified polyisocyanates include N,N',N"-tris-(6-isocyanatohexyl)-biuret and mixtures thereof with its higher homologues and N,N',N"-tris-(6-isocyanatohexyl)-isocyanurate and mixtures thereof with its higher homologues containing more than one isocyanurate ring.

[0023] Isocyanate group-containing prepolymers and semi-prepolymers based on the monomeric simple or modified polyisocyanates exemplified above and organic polyhydroxyl compounds are also suitable for use as a polyisocyanate in the coating compositions useful in the present invention. These prepolymers and semi-prepolymers often have an isocyanate content of 0.5 to 30% by weight, such as 1 to 20% by weight or 10 to 20% by weight, and can be prepared, for example, by reaction of polyisocyanate(s) with polyhydroxyl compound(s) at an NCO/OH equivalent ratio of 1.05:1 to 10:1 , such as 1.1 :1 to 3:1 , this reaction may be followed by distillative removal of any unreacted volatile starting

polyisocyanates still present.

[0024] The prepolymers and semi-prepolymers may be prepared, for example, from low molecular weight polyhydroxyl compounds having a molecular weight of 62 to 299, specific examples of which include, but are not limited to, ethylene glycol, propylene glycol, trimethylol propane, 1 ,6- dihydroxy hexane; low molecular weight, hydroxyl-containing esters of these polyols with dicarboxylic acids; low molecular weight ethoxylation and/or propoxylation products of these polyols; and mixtures of the preceding polyvalent modified or unmodified alcohols.

[0025] In certain embodiments, the prepolymers and semi-prepolymers are prepared from a relatively high molecular weight polyhydroxyl compound having a molecular weight of 300 to 8000, such as 1000 to 5000, as determined from the functionality and the OH number. These polyhydroxyl compounds have at least two hydroxyl groups per molecule and generally have a hydroxyl group content of 0.5 to 17% by weight, such as 1 to 5% by weight.

[0026] Examples of suitable relatively high molecular weight

polyhydroxyl compounds which may be used for the preparation of the prepolymers and semi-prepolymers include polyester polyols based on the previously described low molecular weight, monomeric alcohols and polybasic carboxylic acids such as adipic acid, sebacic acid, phthalic acid, isophthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, maleic acid, the anhydrides of these acids and mixtures of these acids and/or acid anhydrides. Hydroxyl group-containing polylactones, especially poly-ε- caprolactones, are also suitable for the preparation of the prepolymers and semi-prepolymers. [0027] Polyether polyols, which can be obtained by the alkoxylation of suitable starting molecules, are also suitable for the preparation of the isocyanate group-containing prepolymers and semi-prepolymers.

Examples of suitable starting molecules for the polyether polyols include the previously described monomeric polyols, water, organic polyamines having at least two NH bonds and any mixtures of these starting molecules. Ethylene oxide and/or propylene oxide are exemplary suitable alkylene oxides for the alkoxylation reaction. These alkylene oxides may be introduced into the alkoxylation reaction in any sequence or as a mixture.

[0028] Also suitable for the preparation of the prepolymers and semi- prepolymers are hydroxyl group-containing polycarbonates which may be prepared by the reaction of the previously described monomeric diols with phosgene and diaryl carbonates such as diphenyl carbonate.

[0029] In certain embodiments, the polyisocyanate comprises an asymmetric diisocyanate trimer (iminooxadiazine dione ring structure) such as, for example, the asymmetric diisocyanate trimers described in U.S. Pat. No. 5,717,091 , which is incorporated by reference into this specification. In certain embodiments, the polyisocyanate comprises an asymmetric diisocyanate trimer based on HDI, IPDI; or a combination thereof.

[0030] The coating compositions useful in the present invention may also comprise a polymeric polyol. As will be appreciated, the polymeric polyol is distinct from, and in addition to, any polymeric polyol that may be used to prepare an isocyanate group-containing prepolymer or semi- prepolymer described above with respect to the polyisocyanate. In certain embodiments, the polymeric polyol comprises acid, such as carboxylic acid, functional groups.

[0031] Polymeric polyols suitable for use in the compositions useful in the present invention include polyester polyols, polyether polyols, and polycarbonate polyols, such as those described above with respect to the preparation of isocyanate group-containing prepolymers or semi- prepolymers.

[0032] in certain embodiments of the coating compositions useful in the present invention, the polymeric polyol comprises an acrylic polyol, including acrylic polyols that contain acid, such as carboxylic acid, functional groups. Acrylic polyols suitable for use in the coating

compositions of the present invention include hydroxyl-containing copolymers of olefinically unsaturated compounds, such as those polymers that have a number average molecular weight (Mn) determined by vapor pressure or membrane osmometry of 800 to 50,000, such as 1000 to 20,000, or, in some cases, 5000 to 10,000, and/or having a hydroxyl group content of 0.1 to 12% by weight, such as 1 to 10% by weight and, in some cases, 2 to 6% by weight and/or having an acid value of at least 0.1 mg KOH/g, such as at least 0.5 mg KOH/g and/or up to 10 mg KOH/g or, in some cases, up to 5 mg KOH/g. Often, the copolymers are based on olefinic monomers containing hydroxyl groups and olefinic monomers which are free from hydroxyl groups. Examples of suitable olefinic monomers that are free of hydroxyl groups include vinyl and vinylidene monomers, such as styrene, a-methyl styrene, o- and p-chloro styrene, o-, m- and p-methyl styrene, p-tert-butyl styrene; acrylic acid; methacrylic acid; (meth)acrylonitrile; acrylic and methacrylic acid esters of alcohols containing 1 to 8 carbon atoms, such as ethyl acrylate, methyl acrylate, n- and iso-propyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, iso-octyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate and iso-octyl methacrylate; diesters of fumaric acid, itaconic acid or maleic acid having 4 to 8 carbon atoms in the alcohol component; (meth)acrylic acid amide; and vinyl esters of alkane monocarboxylic acids having 2 to 5 carbon atoms, such as vinyl acetate or vinyl propionate. Examples of suitable olefinic monomers containing hydroxyl groups are hydroxyalkyl esters of acrylic acid or methacrylic acid having 2 to 4 carbon atoms in the hydroxyalkyl group, such as 2- hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate, 4- hydroxybutyl(meth)acrylate and trimethylolpropane-mono- or

pentaerythritomono-(meth)acrylate. Mixtures of the monomers exemplified above may also be used for the preparation of the acrylic polyol. As will be appreciated, (meth)acrylate and (meth)acrylic is meant to encompass methacrylate and acrylate or methacrylic and acrylics, as the case may be. Mixtures of the various polymeric polyols described above may be used.

[0033] The coating compositions useful in the present invention also comprises a polyaspartic ester corresponding to the formula (I):

[0034] wherein: X is an aliphatic residue, R and R² are organic groups that are inert to isocyanate groups at a temperature of 100°C or less and may be the same or different organic groups, and n is an integer having a value of at least 2, such as 2 to 6 or 2 to 4.

[0035] In certain embodiments, X in formula (I) is a straight or branched alky! and/or cycloalkyi residue of an n-valent polyamine that is reacted with a dialkylmaleate in a Michael addition reaction to produce a polyaspartic ester. For example, X may be an aliphatic residue from an n-valent polyamine including, but not limited to, ethylene diamine; 1 ,2- diaminopropane; ,4-diaminobutane; 1 ,6-diaminohexane; 2,5-diamino-2,5- dimethylhexane; 2,2,4- and/or 2,4, 4-trimethyl-1 ,6-diaminohexane; 1 ,11- diaminoundecane; 1 , 2-diaminododecane; 1 -amino-3,3,5-trimethyl-5- amino-methylcyclohexane; 2,4'- and/or 4,4'-diaminodicyclohexylmethane; 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane; 2,4,4'-triamino-5- methyldicyclohexylmethane; polyether polyamines with aliphatically bound primary amino groups and having a number average molecular weight (Mn) of 148 to 6000 g/mol; isomers of any thereof, and combinations of any thereof.

[0036] In certain embodiments, X may be obtained from ,4- diaminobutane; 1 ,6-diaminohexane; 2,2,4- and/or 2,4,4-trimethyl-1 ,6- diaminohexane; 1 -amino-3,3,5-trimethyl-5-aminomethylcyclohexane; 4,4'- diaminodicyclohexylmethane; 3,3'-dimethyl-4,4'- diaminodicyclohexylmethane; or 1 ,5-diamine-2-methyl-pentane.

[0037] As used herein, the phrase "inert to isocyanate groups," which is used to define groups Ri and R2 in formula (I), means that these groups do not have Zerevitinov-active hydrogens. Zerevitinov-active hydrogen is defined in Rompp's Chemical Dictionary (Rommp Chemie Lexikon), 10^th ed., Georg Thieme Verlag Stuttgart, 1996, which is incorporated herein by reference. Generally, groups with Zerevitinov-active hydrogen are understood in the art to mean hydroxyl (OH), amino (NHx), and thiol (SH) groups. In various embodiments, Ri and R2, independently of one another, are Ci to C10 alkyl residues, such as, for example, methyl, ethyl, or butyl residues.

[0038] In certain embodiments, n in formula (I) is an integer having a value of from 2 to 6, such as from 2 to 4, and in some embodiments, n is 2.

[0039] The polyaspartic ester present in the coating compositions of the present invention may be produced by reacting a primary polyamine of the formula:

[0040] with maleic or fumaric acid esters of the formula:

R¹ OOC C C COOR²

H H [0041] wherein X, n, R¹ and R² are as described earlier with respect to formula (I).

[0042] Examples of suitable polyamines include the above-mentioned diamines. Examples of suitable maleic or fumaric acid esters include dimethyl maleate, diethyl maleate, dibutyl maleate, and the corresponding fumarates.

[0043] The production of the polyaspartic ester from the above- mentioned polyamine and maleic/fumaric acid ester starting materials may take place within a temperature range of, for example, 0°C to 100°C. The starting materials may be used in amounts such that there is at least one equivalent, and in some embodiments approximately one equivalent, of olefinic double bonds in the maleic/fumaric acid esters for each equivalent of primary amino groups in the polyamine. Any starting materials used in excess may be separated off by distillation following the reaction. The reaction may take place in the presence or absence of suitable solvents, such as methanol, ethanol, propanol, dioxane, or combinations of any thereof.

[0044] In certain embodiments, the polyaspartic ester comprises a reaction product of two equivalents of diethyl maleate with one equivalent of 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane. Such a reaction product has the following molecular structure:

[0045] In certain embodiments, the polyaspartic ester comprises a mixture of any two or more polyaspartic esters.

[0046] Examples of suitable polyaspartic esters that may be used in the coating compositions of the present invention are also described in U.S. Pat. Nos. 5,126,170; 5,236,741 ; 5,489,704; 5,243,012; 5,736,604;

6,458,293; 6,833,424; 7,169,876; and in U.S. Patent Publication No.

2006/0247371 , In addition, suitable polyaspartic esters are commercially available from Covestro LLC, Pittsburgh, Pa., USA, under the

DESMOPHEN trade name.

[0047] In certain embodiments, the components in the coating compositions are included in amounts sufficient to provide an equivalent ratio of isocyanate groups to isocyanate-reactive groups of 0.8:1 to 20:1 , such as 0.8:1 to 2:1 , or, in some cases, 0.8: 1 to 1.2:1 or 1 :1.

[0048] In various embodiments, the coating compositions are applied to metallic surfaces that have been pretreated with a pretreatment composition containing one or more of iron phosphate, zinc phosphate (with and without chrome), zirconium, titanium, vanadium or hafnium. As used herein, the term "pretreatment composition" refers to a composition that upon contact with the substrate, reacts with and chemically alters the substrate surface and binds to it to form a protective layer. In certain preferred embodiments, the coating compositions are applied to steel that has been pretreated with zirconium.

[0049] Iron phosphate pretreatments, also known as alkali metal phosphates, are used for parts that require a durable finish but are not exposed to severely corrosive environments. These pretreatments can involve two to six stages, with the shortest sequence being a cleaner- coater stage followed by a tap-water rinse. Short sequence pretreatments are employed if performance requirements are low.

[0050] Parts that are more difficult to clean or have higher quality requirements call for a separate cleaning stage, appropriate rinse tanks, iron phosphate, post-treatment rinse and a deionized (Dl) water rinse. A post-treatment rinse (chrome or chrome-free) results in improved corrosion performance over the phosphate alone.

[0051] Iron phosphate pretreatments produce an amorphous

conversion coating on steel that ranges in color from iridescent blue to gray, depending on operating conditions and product formulation. Mixed metals may be treated with modified formulas that typically contain fluoride.

[0052] Iron phosphate pretreatment processes are much easier to operate and require fewer process stages than zinc phosphate

pretreatments. A drawback however is that iron phosphates do not provide the degree of corrosion protection imparted by zinc phosphates.

[0053] A zinc phosphate pretreatment varies from an iron based pretreatment in two critical areas. First, it requires the use of a surface conditioner stage. Second, a zinc phosphate bath has additional metal ions in the solution which are incorporated into the coating along with the metal ions from the substrate being processed.

[0054] As those skilled in the art will appreciate, various embodiments of the invention are particularly suitable for production line processes utilizing two or more vessels containing the desired solutions or baths which may or may not be heated. One such multistage zirconium based dipping (or immersion) pretreatment process is depicted in the schematic of FIG. 1. Alternatively, in various other embodiments of the present invention, the pretreatment process may involve spraying the pretreatment onto the metal to be coated.

[0055] In various embodiments of the methods of the present invention, after the substrate is dipped or immersed in the pretreatment composition, in various other embodiments, the substrate is sprayed with the

pretreatment composition, it is then contacted with a coating composition comprising a film-forming resin. Any suitable technique may be used to contact the substrate with such a coating composition, including, for example, spraying, dipping, flow coating, rolling, brushing, pouring, and the like. The coating compositions may be applied in the form of paints or lacquers onto any compatible substrate, such as, for example, metals, plastics, ceramics, glass, and natural materials. In certain preferred embodiments, the coating composition is applied as a single layer. In certain other embodiments, it may be applied as multiple layers as needed. In the various methods of embodiments of the present invention, the coating composition cures at ambient (room) temperature, thus eliminating the requirement for a primer layer, primer oven, and topcoat oven. The coating compositions of the present invention provide coatings having a mean corrosion creepage as measured by ASTM- D-1654 in certain embodiments of no greater than 5 mm, in certain other

embodiments of no greater than 3 mm and in various other embodiments of no greater than 1 mm.

[0056] Certain embodiments of the present invention are directed to methods for coating a metal substrate. Suitable metal substrates for use in the present invention include those that are often used in the assembly of agricultural and construction equipment ("ACE") such as heavy trucks, road paving and earth-moving machinery, tractors, bulldozers, cranes, planting, and harvesting machinery, such as sprayers, combines, disc harrows, tine harrows, chain harrows, chain disk harrows balers, graders, cotton-ginning machinery, locomotives, as well as commercial shovels, lawn mowers and other commercial landscaping equipment.

[0057] Other suitable metal substrates include automotive bodies, automotive parts, home appliances (refrigerators, washers dryers, ranges, dishwashers), furnaces, air conditioning units and other articles, such as small metal parts, including fasteners, i.e., nuts, bolts, screws, pins, nails, clips, buttons, and the like. [0058] Specific examples of suitable metal substrates include, but are not limited to, stainless steel, cold rolled steel, hot rolled steel, steel coated with zinc metal, zinc compounds, or zinc alloys, such as electrogalvanized steel, hot-dipped galvanized steel, galvanealed steel, and steel plated with zinc alloy. Also, aluminum alloys, aluminum plated steel and aluminum alloy plated steel substrates may be used. Other suitable non-ferrous metals include copper and magnesium, as well as alloys of these materials. The metal substrate may be in the form of, for example, a sheet of metal or a fabricated part.

[0059] As shown in FIG. 2, a comparison of three pretreatments after salt spray (fog) testing for 500 hours according to ASTM- D-1654: iron phosphate, ZIRCOBOND (zirconium based, commercially available from PPG Industries, Inc.) and NPLF (zirconium based, commercially available from Coral Chemical Co.) shows that not all zirconium based

pretreatments behave in the same manner.

[0060] Certain embodiments of the invention are directed to a composite. The composite comprises a substrate covered by a layer of pretreatment composition and then a layer of coating composition. In various embodiments, the substrate is a metal, a plastic, a ceramic, glass, and natural materials. In some embodiments, the layer of pretreatment composition contains at least one of iron phosphate, zinc phosphate, zirconium, titanium, vanadium and hafnium. The layer of coating composition is the reaction product of an aliphatic polyisocyanate and an isocyanate reactive compound(s) at least one of which is a polyaspartic acid ester.

[0061] The coating compositions useful in the present invention may comprise any of a variety of conventional auxiliary agents or additives, such as, but not limited to, defoamers, rheology modifiers (e.g.,

thickeners), leveling agents, flow promoters, colorants, fillers, UV stabilizers, dispersing agents, catalysts, anti-skinning agents, anti- sedimentation agents, emulsifiers, and/or organic solvents.

EXAMPLES

[0062] The non-limiting and non-exhaustive examples that follow are intended to further describe various non-limiting and non-exhaustive embodiments without restricting the scope of the embodiments described in this specification. All quantities given in "parts" and "percents" are understood to be by weight, unless otherwise indicated.

[0063] Coating compositions were made with a traditional high speed disperser using the following ingredients and amounts (parts by weight) listed in Table I.

[0064] Anti-corrosion pigment - a zinc aluminum orthophosphate hydrate commercially available from Heubach GmbH as HEUCOPHOS ZPA;

[0065] Antioxidant - a hindered phenol antioxidant (3,5-di-t-4-hydroxy- hydrocinnamic acid and C7-9-branched alkyl esters), commercially available from Ciba Specialty Chemicals as IRGANOX 1 135;

[0066] Catalyst - dibutyltin dilaurate, commercially available from Air Products as DABCO T-12;

[0067] Dispersion stabilizer - commercially available from BYK Chemie as DISPERBYK-1 1 1 ;

[0068] Fluoropolymer - a solvent soluble fluoropolymer commercially available from Asahi Glass Co., Ltd. as LUMIFLON LF-910LM;

[0069] Isocyanate A - a solvent-free, aliphatic polyisocyanate resin based on hexamethylene diisocyanate (HDI) having an NCO content of 22.0% ± 0.2; viscosity 7,500 ± 2,500 mPa-s @ 25°C commercially available from Covestro as DESMODUR N-100; [0070] Isocyanate B - an aliphatic polyisocyanate resin based on hexamethylene diisocyanate (HDI); HDI trimer having an NCO content of 19.6% ± 0.3; solids 90 ± 1 %; viscosity 500 ± 150 mPa s @ 25°C commercially available from Covestro as DESMODUR N-3390 BA/SN;

[0071] Isocyanate C - a hydrophilic aliphatic polyisocyanate based on hexamethylene diisocyanate (HDI) with an NCO content of 2.07-21.7%; monomeric isocyanate content <0.3% by wt; viscosity 3500 ± 1000 @ 25°C; mPa-s commercially available from Covestro as BAYHYDUR XP 2655;

[0072] Isocyanate D - a solvent free aliphatic polyisocyanate resin based on hexamethylene diisocyanate (HDI) having an NCO content of 23.0%) ± 0.5; viscosity 1 ,750 ± 450 mPa-s @ 25°C commercially available from Covestro as DESMODUR N-3200;

[0073] Isocyanate E - a silane-functional aliphatic polyisocyanate based on hexamethylene diisocyanate with an NCO content of 15.9 wt.% commercially available from Covestro as DESMODUR XP 2714;

[0074] Isocyanate F - an aliphatic polyisocyanate based on isophorone diisocyanate (IPDI) and hexamethylene diisocyanate (HDI) having a viscosity of 2000 ± 500 mPa s at 25°C; NCO content of 10.2 ± 1.0% commercially available from Covestro as DESMODUR XP 2763;

[0075] Isocyanate G - a solvent-free, flexibilizing aliphatic

polyisocyanate resin based on hexamethylene diisocyanate (HDI); HDI trimer with an NCO content of 1 1.0 ± 0.5%; viscosity 6,000 ± ,200 mPa-s @ 23°C commercially available from Covestro as DESMODUR N 3800;

[0076] Isocyanate H - a low-viscosity, aliphatic polyisocyanate resin based on isophorone diisocyanate (IPDI), having NCO content 12.0 ± 0.5%, viscosity 2,800 ± 500 mPa-s @ 23°C, commercially available from Covestro as DESMODUR XP 2565; [0077] Isocyanate I - an aliphatic polyisocyanate prepolymer based on isophorone diisocyanate (IPDI), having an NCO content of 3.7 ± 0.3%, viscosity of 9,800 ± 2,500 mPa s @ 23°C, commercially available from Covestro as DESMODUR VP LS 2371 ;

[0078] Isocyanate J - an aliphatic polyisocyanate based on

hexamethylene diisocyanate (HDI); high functional HDI trimer; NCO content 17.8 ± 0.5; viscosity 1 ,800 ± 500 mPa-s @ 23°C, commercially available from Covestro as DESMODUR N-3790;

[0079] Light stabilizer A - a hindered amine UV stabilizer, commercially available from Ciba Specialty Chemicals as TINUVIN 1130;

[0080] Light stabilizer B - a hindered amine light stabilizer ("HALS"), commercially available from Ciba Specialty Chemicals as TINUVIN 292;

[0081] Organoclay - a modified bentonite organoclay commercially available as BENTONE SD-2 ;

[0082] Polyaspartate A - an aspartic ester functional amine

commercially available from Covestro as DESMOPHEN NH 1420;

[0083] Polyaspartate B - an aspartic ester functional amine

commercially available from Covestro as DESMOPHEN NH 1520;

[0084] Polyaspartate C - an aspartic ester functional amine

commercially available from Covestro as DESMOPHEN NH 1521 ;

[0085] Polyaspartate D - an aspartic ester functional amine

commercially available from Covestro as DESMOPHEN NH 2850 XP;

[0086] Polyaspartate E - a polyaspartic acid ester{an aspartic ester functional amine} having an amine value of 202 mg KOH/g, viscosity @ 25°C of 1 100-2200 mPa^»s, commercially available from Covestro as DESMOPHEN NH XP-2701 ;

[0087] Surface additive - a polyether-modified polysiloxane compound, commercially available from BYK Chemie as BYK-307; [0088] Silane - a γ-isocyanatopropyltriethoxysilane commercially available from Momentive Performance Materials Inc.as SILQUEST A- 1310;

[0089] Solvent - n-butyl acetate;

[0090] Titanium dioxide A - commercially available from Kronos, Inc. as KRONOS 2310; and

[0091] Titanium dioxide B - commercially available from DuPont as Ti- Pure R-706.

Table I

Component/Sample A B C D E F

Acrylic polyol

Solvent

Polyaspartate A 9.71 10.65 6.87 9.13 8.52 9.4

Polyaspartate B 10.65

Polyaspartate C 10.79 7.64 9.46 10.45

Polyaspartate D 9.13

Surface additive 0.74 0.79 0.72 1.05 0.72 0.73

Fluoropolymer 3.23

Methyl n-amyl ketone 27.71 23.46 25.49 24.68 26.77 27.76

Dispersion stabilizer 0.17 0.19 0.7 0.7 0.7 0.17

Anti-corrosion pigment 4.5 4.78 4.4 4.44 4.39 4.43

Titanium dioxide A 15.39 16.23 15.06 15.09 15.02 15.14

Titanium dioxide B

Microcrystalline silica

Talc 15.8 16.77 15.46 15.59 15.43 15.55

Barium sulfate

Silane 0.93 0.45 0.91 0.7 0.91 0.91

Organoclay

Isocyanate A 14.25 16.03 13.71

Light stabilizer A 0.66 0.7 0.66 0.66

Light stabilizer B 0.33 0.35 0.33 0.33

Catalyst

Antioxidant 0.16 0.18 0.16 0.17

Isocyanate B

Isocyanate C 14.32

Isocyanate D 8.44

Isocyanate E

Isocyanate F 17.78 9.81

Isocyanate G 3.82

Formulation Results

PVC 26.48 25.31 26.33 25.15 26.79 26.62

NCO:OH 1.1 1.15 1 .11 1.1 1.1 1.1

Weight Solids 70.54 75.83 70.61 73 70.54 70.54

Mix Ratio (vol.) 5.31 :1 1 .61 :1 2.92:1 3.68:1 5.56:1 5.40:1

P/B 1.06 1 1.06 1 1.06 1 .06

%NCO 0.22

Volume Solids 54.6 61.33 55.24 58.4 54.65 54.68

Wt Gal 10.58 10.96 10.5 10.59 10.58 10.56

VOC 3.12 2.65 3.09 2.86 3.12 3.1 1 Table I continued

Component/Sample G H I J K L

Acrylic polyol 34.09

Solvent 9.6

Polyaspartate A 8.5 9.55 10.39 8.22 9.55

Polyaspartate B 10.39

Polyaspartate C 9.45 10.61 9.13 10.61

Polyaspartate D

Surface additive 0.72 0.73 0.77 0.73 0.73 0.19

Fluoropolymer

Methyl n-amyl ketone 26.5 27.74 23.47 27.89 27.74 9.8

Dispersion stabilizer 0.7 0.18 0.74 0.17 0.18 1.62

Anti-corrosion pigment 4.4 4.43 4.67 4.21 4.43 5.54

Titanium dioxide A 15.06 15.13 15.86 15.8 15.13

Titanium dioxide B 7.68

Microcrystalline silica 15.54 16.33 15.1 15.54 3.86

Talc 15.46

Barium sulfate 17.37

Silane 0.91 0.91 0.44 0.91 0.91

Organoclay 0.77

Isocyanate A 14.02 15.64 14.02

Light stabilizer A 0.66 0.66 0.74 0.66 0.66

Light stabilizer B 0.33 0.33 0.37 0.33 0.33

Catalyst 1.34

Antioxidant 0.16 0.17 0.18 0.17 0.17

Isocyanate B 8.13

Isocyanate C

Isocyanate D 7.93

Isocyanate E 16.69

Isocyanate F 9.22

Isocyanate G

Formulation Results

PVC 26.34 27.03 25.84 27 27.03 27.77

NCO:OH 1.1 1 1.1 1.15 1.1 1.1 1.1

Weight Solids 70.61 70.54 75.83 70.54 70.54 64.64

Mix Ratio (vol.) 4.03:1 5.48:1 1.67:1 4.42:1 5.48:1 9.25:1

P/B 1.06 1.06 1 1.06 1.06 1.24

%NCO 0.15

Volume Solids 55.18 54.99 61.76 54.83 54.99 48.03

Wt/Gal 10.49 10.49 10.84 10.52 10.49 11.32

VOC 3.08 3.09 2.62 3.1 3.09 3.47 BMS152014

-23-

[0092] The following pretreatments were used with each of the coating compositions: an iron-based pretreatment, in which iron phosphate

(BONDERITE 1000) was sprayed on to steel panels and sealed with a chrome-containing sealer (PARCOLENE 60).; a zinc phosphate chrome-free pretreatment (ACT Test Panels), in which steel panels were sprayed with zinc phosphate (BONDERITE 952) and sealed with a chromium and phosphate free sealer (PARCOLENE 99X); a zirconium-based pretreatment; and a zinc phosphate chrome pretreatment (ACT Test Panels), in which steel panels were sprayed with zinc phosphate (BONDERITE 952) and sealed with a chrome containing sealer (PARCOLENE 60).

[0093] A single layer (~3 mils) of each of the coating compositions as detailed in Table I was applied to the pretreated panels. None of the panels was subjected to oven baking or other heating to cure the coating. The applied coating compositions cured at ambient (room) temperature for one week before the creepage (maximum and mean) of the panels was measured according to ASTM D-1654 (Salt spray (fog)). The results are reported in Table II.

[0094] As can be appreciated by reference to the salt spray (fog) results in Table II, the polyaspartic ester based coating compositions demonstrated better performance over zirconium-based pretreatment when applied to metal surfaces. The polyaspartic ester based coating compositions also showed better performance over a pretreatment with a chrome-free sealer. For comparison purposes, Formulation L was included which was a standard two- component, solvent-based polyurethane (made with an acrylic polyol) that showed poor performance over zirconium-based pretreatment. BMS152014

-24-

Table II

[0095] The use of polyaspartic ester based coating compositions eliminates the need for a primer layer, primer oven, and topcoat oven while maintaining corrosion resistance over zirconium-based pretreatments.

Various workers in the art have attempted to use two-component, solvent- based polyurethanes over zirconium-based pretreatment for the elimination of the primer but have been unable to show equal salt spray (fog) results to iron- based pretreatment. Referring again to Table II, the salt spray (fog) results showed better performance of polyaspartic coatings over zirconium-based pretreatment than over iron-based pretreatment.

[0096] This is illustrated in FIGS. 2A, 2B and 2C which depict a

comparison of three pretreatments after salt spray (fog) testing for 500 hours according to ASTM- D-1654: iron phosphate (FIG. 2A), ZIRCOBOND BMS152014

-25-

(zirconium based, FIG. 2B) and NPLF (zirconium based, FIG. 2C). These results also indicate that all zirconium based pretreatments are not the same.

[0097] An attempt was made to establish a correlation between corrosion resistance and adhesion. The formulations are provided in Table III.

Crosshatch adhesion testing was conducted according to ASTM D3359-09 using an adhesion scale ranging from 0-5, with 0 being the worst, and 5 being the best. Corrosion resistance was measured by salt spray (fog) according to ASTM D-1654 with any creepage greater than 3 mm being considered a failure for this analysis.

[0098] The following pretreatments were used with each of the coating compositions: Pretreatment 1 - an iron-based pretreatment, in which iron phosphate (BONDERITE 1000) was sprayed on steel panels and sealed with a chrome containing sealer (PARCOLENE 60); Pretreatment 2 - a zinc phosphate chrome pretreatment, in which steel panels were sprayed with zinc phosphate (BONDERITE 952) and sealed with a chrome containing sealer (PARCOLENE 60) and Pretreatment 3 - a zinc phosphate chrome-free pretreatment, in which steel panels were sprayed with zinc phosphate

(BONDERITE 952) and sealed with a chromium and phosphate free sealer (PARCOLENE 99X).

[0099] A single layer (~3 mils) of each of the coating compositions as detailed in Table III was applied to the pretreated panels. None of the panels was subjected to oven baking or other heating to cure the coating. The applied coating compositions cured at ambient (room) temperature for one week before creepage and adhesion were measured.

[0100] The results of this testing are provided in Table IV. As can be appreciated by reference to Table IV, good initial adhesion provides no indication of good corrosion resistance as measured by salt spray (fog). The B S152014

-26- corrosion resistance and adhesion properties appear to be independent of each other.

Table III

Component/Sample P Q R S T U

Polyaspartate A 45.28 31.42 37.59 35.12

Polyaspartate C 64.58 44.59 53.35 49.85

Polyaspartate D

Polyaspartate E 80.18 100.49

Surface additive 9.27 7.87 7.89 7.82 7.87 7.85

Methyl n-amyl ketone 56.47 41.93 46.03 46.37 43.30 50.56

Dispersion stabilizer 2.09 1.79 1.79 1 .78 1.79 1.78

Anti-corrosion 46.78 pigment 54.27 46.86 47.03 46.62 46.88

Titanium dioxide A 185.59 160.23 160.81 159.40 160.31 159.95

Talc 190.60 164.56 165.16 163.71 164.64 _j 164.28

Polyaspartate A 73.82 50.97 60.99 56.99

Polyaspartate C 67.74 46.79 55.98 52.31

Polyaspartate E 80.18 100.49

Iron Oxide Pigment 9.75 8.40 8.43 8.36 8.40 8.38

Methyl n-amyl ketone 9.66 7.17 7.88 7.93 7.41 8.65

Silane 11.42 9.87 9.90 9.82 9.87 9.85

Isocyanate A 175.95 155.92

Methyl n-amyl ketone 273.99 203.47 223.39 225.03 210.14 245.37

Isocyanate D 85.81

Isocyanate F 99.78

Isocyanate H 217.01 222.01

Isocyanate I 19.29 18.73

Isocyanate J 179.84

Formulation

Results

PVC 26.40 26.31 26.61 26.21 26.39 26.51

NCO:OH 1.11 1.1 1 1.11 1.1 1 1 .1 1 1.11

Weight Solids 70.61 70.61 70.61 70.61 70.61 70.61

Mix Ratio (vol.) 0.98:1 0.77:1 0.93:1 0.87:1 0.72:1 0.91 :1

P/B 1.06 1.06 1.06 1.06 1 .06 1 .06

Volume Solids 54.62 54.94 54.54 54.87 54.81 54.44

Wt/Gal 10.60 10.62 10.66 10.57 10.63 10.60

VOC 3.12 3.12 3.13 3.1 1 3.12 3.12 Table IV

[0101] This specification has been written with reference to various non-limiting and non-exhaustive embodiments. However, it will be recognized by persons having ordinary skill in the art that various substitutions, modifications, or combinations of any of the disclosed embodiments (or portions thereof) may be made within the scope of this specification. Thus, it is contemplated and understood that this

specification supports additional embodiments not expressly set forth herein. Such embodiments may be obtained, for example, by combining, modifying, or reorganizing any of the disclosed steps, components, elements, features, aspects, characteristics, limitations, and the like, of the various non-limiting embodiments described in this specification. In this manner, Applicant(s) reserve the right to amend the claims during prosecution to add features as variously described in this specification, and such amendments comply with the requirements of 35 U.S.C.

§1 12(a), and 35 U.S.C. §132(a).

[0102] Various aspects of the subject matter described herein are set out in the following numbered clauses:

[0103] 1 . A method of coating a surface of a substrate comprising: pretreating the substrate with a pretreatment composition; curing the pretreatment composition; applying over the cured pretreatment composition a coating composition comprising an aliphatic polyisocyanate and an isocyanate reactive compound comprising at least one polyaspartic acid ester; and curing the coating composition, wherein the coated substrate has a mean corrosion creepage as measured by ASTM D 1654 of less than 3 mm.

[0104] 2. The method according to clause 1 , wherein the substrate comprises a one member selected from the group consisting of metals, plastics, ceramics, glass, and natural materials. [0105] 3. The method according to one of clauses 1 and 2, wherein the the step of pretreating comprises dipping the substrate into the

pretreatment composition.

[0106] 4. The method according to one of clauses 1 and 2, wherein the step of pretreating comprises spraying the pretreatment composition onto the substrate.

[0107] 5. The method according to one of clauses 1 to 4, wherein the pretreatment composition comprises one or more selected from the group consisting of iron phosphate, zinc phosphate, zirconium, titanium, vanadium and hafnium.

[0108] 6. The method according to any one of clauses 1 to 5, wherein the pretreatment composition contains zirconium.

[0109] 7. The method according to any one of clauses 1 to 6, wherein the coating composition cures at ambient temperature.

[0110] 8. The method according to any one of clauses 1 to 7, wherein the coating composition comprises a single layer.

[0111] 9. The method according to any one of clauses 1 to 8, wherein the substrate comprises a metal.

[0112] 0. The method according to any one of clauses 1 to 9, wherein the substrate comprises one or more metals selected from the group consisting of stainless steel, cold rolled steel, hot rolled steel,

electrogalvanized steel, hot-dipped galvanized steel, galvanealed steel, steel plated with zinc alloy, aluminum alloy, aluminum plated steel, aluminum alloy plated steel, and magnesium or an alloy thereof.

[0113] 1 1. The method according to any one of clauses 1 to 10, wherein the substrate comprises agricultural and construction equipment selected from the group consisting of heavy trucks, road paving and earth- moving machinery, tractors, bulldozers, cranes, sprayers, combines, disc harrows, tine harrows, chain harrows, chain disk harrows balers, graders, cotton-ginning machinery, locomotives, commercial shovels, lawn mowers and commercial landscaping equipment.

[0114] 12. The method according to any one of clauses 1 to 1 1 , wherein the substrate is selected from the group consisting of automotive bodies, automotive parts, refrigerators, washers dryers, ranges, dishwashers, furnaces, air conditioning units small metal parts, nuts, bolts, screws, pins, nails, clips, and buttons.

[0115] 13. The method according to any one of clauses 1 to 12, wherein the coating composition comprises a paint.

[0116] 14. The method according to any one of clauses 1 to 13, wherein the coating composition is applied by one or more selected from the group consisting of spraying, dipping, flow coating, rolling, brushing and pouring.

[0117] 15. The method according to any one of clauses 1 to 14, wherein the aliphatic polyisocyanate is selected from the group consisting of hexamethylene diisocyanate (HDI), pentamethylene diisocyanate (PDI), 2,2,4- and/or 2,4,4-trimethyl-1 ,6-hexamethylene diisocyanate,

dodecamethylene diisocyanate, 1 ,4-diisocyanatocyclohexane, 1- isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (IPDI), 2,4'- and/or 4,4'-diisocyanato-dicyclohexyl methane, 2,4- and/or 4,4'- diisocyanato-diphenyl methane and mixtures of these isomers.

[0118] 16. The method according to any one of clauses 1 to 15, wherein the coated substrate has a mean corrosion creepage as measured by ASTM- D-1654 of less than 1 mm.

[0119] 17. The method according to any one of clauses 1 to 16, wherein the method is conducted in a production line process comprising two or more vessels.

[0120] 18. A composite comprising a substrate comprising at least one member selected from the group consisting of metals, plastics, ceramics, glass, and natural materials; a layer of pretreatment composition comprising at least one of iron phosphate, zinc phosphate, zirconium, titanium, vanadium and hafnium; and a layer of coating composition comprising an aliphatic polyisocyanate and an isocyanate reactive compound comprising at least a polyaspartic acid ester, wherein the composite exhibits a mean corrosion creepage as measured by ASTM D 1654 of not greater than 3 mm.

[0121] 19. The composite according to clause 18, wherein the substrate comprises a metal.

[0122] 20. The composite according to clause 9, wherein the substrate comprises one or more metals selected from the group consisting of stainless steel, cold rolled steel, hot rolled steel,

[0123] 21. The composite according to clause 20, wherein the substrate comprises agricultural and construction equipment selected from the group consisting of heavy trucks, road paving and earth-moving machinery, tractors, bulldozers, cranes, sprayers, combines, disc harrows, tine harrows, chain harrows, chain disk harrows balers, graders, cotton- ginning machinery, locomotives, commercial shovels, lawn mowers and commercial landscaping equipment.

[0124] 22. The composite according to clause 21 , wherein the substrate is selected from the group consisting of automotive bodies, automotive parts, refrigerators, washers dryers, ranges, dishwashers, furnaces, air conditioning units small metal parts, nuts, bolts, screws, pins, nails, clips, and buttons.

[0125] 23. The composite according to any one of clauses 18 to 22, wherein the coating composition comprises a single layer.

[0126] 24. The composite according to any one of clauses 18 to 23, wherein the coating composition comprises a paint. [0127] 25. The composite according to any one of clauses 18 to 24, wherein the pretreatment composition contains zirconium.

[0128] 26. A composite comprising; a substrate comprising a metal; a layer of pretreatment composition comprising at least one of iron phosphate, zinc phosphate, zirconium, titanium, vanadium and hafnium; and a single layer of a coating composition comprising an aliphatic polyisocyanate and an isocyanate reactive compound comprising at least a polyaspartic acid ester, wherein the composite has a mean corrosion creepage as measured by ASTM D-1654 of less than 3 mm.

[0129] 27. A composite comprising; a substrate comprising a metal; a layer of pretreatment composition comprising at least one of iron phosphate, zinc phosphate, zirconium, titanium, vanadium and hafnium; and a single layer of a coating composition comprising an aliphatic polyisocyanate and an isocyanate reactive compound comprising at least a polyaspartic acid ester, wherein the composite has a mean corrosion creepage as measured by ASTM D-1654 of less than 1 mm.

Claims

WHAT IS CLAIMED IS:

1 . A method of coating a surface of a substrate comprising:

pretreating the substrate with a pretreatment composition;

curing the pretreatment composition;

applying over the cured pretreatment composition a coating composition comprising an aliphatic polyisocyanate and an isocyanate reactive compound comprising at least one polyaspartic acid ester; and curing the coating composition,

wherein the coated substrate has a mean corrosion creepage as measured by ASTM D 1654 is not greater than 3 mm.

2. The method according to Claim 1 , wherein the pretreatment composition comprises one or more selected from the group consisting of iron phosphate, zinc phosphate, zirconium, titanium, vanadium and hafnium.

3. The method according to one of Claims 1 and 2, wherein the step of pretreating comprises dipping the substrate into the pretreatment composition.

4. The method according to one of Claims 1 and 2, wherein the step of pretreating comprises spraying the pretreatment composition onto the substrate.

5. The method according to one of Claims 1 to 4, wherein the pretreatment composition contains zirconium.

6. The method according to any one of Claims 1 to 5, wherein the coating composition cures at ambient temperature.

7. The method according to any one of Claims 1 to 6, wherein the coating composition comprises a single layer.

8. The method according to any one of Claims 1 to 7, wherein the substrate comprises one or more metals selected from the group consisting of stainless steel, cold rolled steel, hot rolled steel,

9. The method according to any one of Claims 1 to 8, wherein the substrate comprises agricultural and construction equipment selected from the group consisting of heavy trucks, road paving and earth-moving machinery, tractors, bulldozers, cranes, sprayers, combines, disc harrows, tine harrows, chain harrows, chain disk harrows balers, graders, cotton- ginning machinery, locomotives, commercial shovels, lawn mowers and commercial landscaping equipment.

10. The method according to any one of Claims 1 to 9, wherein the coating composition comprises a paint.

11. The method according to any one of Claims 1 to 10, wherein the coated substrate has a mean corrosion creepage as measured by ASTM D-1654 of less than 1 mm.

12. The method according to one of Claims 1 to 1 , wherein the method is conducted in a production line process comprising two or more vessels.

A composite comprising a substrate comprising at least one member selected from the group consisting of metals, plastics, ceramics, glass, and natural materials;

a layer of pretreatment composition comprising at least one of iron

phosphate, zinc phosphate, zirconium, titanium, vanadium and hafnium; and

a layer of coating composition comprising an aliphatic polyisocyanate and an isocyanate reactive compound comprising at least a polyaspartic acid ester,

wherein the composite exhibits a mean corrosion creepage as measured by ASTM D 1654 of not greater than 3 mm.

14. The composite according to Claim 13, wherein the substrate comprises one or more metals selected from the group consisting of stainless steel, cold rolled steel, hot rolled steel, electrogalvanized steel, hot-dipped galvanized steel, galvanealed steel, steel plated with zinc alloy, aluminum alloy, aluminum plated steel, aluminum alloy plated steel, and magnesium or an alloy thereof.

15. The composite according to Claim 3, wherein the substrate comprises one member selected from the group consisting of heavy trucks, road paving and earth-moving machinery, tractors, bulldozers, cranes, sprayers, combines, disc harrows, tine harrows, chain harrows, chain disk harrows balers, graders, cotton-ginning machinery, locomotives, commercial shovels, lawn mowers, commercial landscaping equipment, automotive bodies, automotive parts, refrigerators, washers dryers, ranges, dishwashers, furnaces, air conditioning units small metal parts, nuts, bolts, screws, pins, nails, clips, and buttons.

16. The composite according to any one of Claims 13 to 15, wherein the coating composition comprises a single layer.

17. The composite according to any one of Claims 3 to 16, wherein the coating composition comprises a paint.

18. A composite comprising;

a substrate comprising a metal;

a layer of pretreatment composition comprising at least one of iron

phosphate, zinc phosphate, zirconium, titanium, vanadium and hafnium; and

a single layer of a coating composition comprising an aliphatic

polyisocyanate and an isocyanate reactive compound comprising at least a polyaspartic acid ester,

wherein the composite has a mean corrosion creepage as measured by

ASTM D-1654 of less than 1 mm.