KR20070067009A - Method of stabilizing metal pigments against gassing - Google Patents

Abstract

The present invention is directed to a passivating material suitable for passivating a metal surface. The passivating material comprises a polymer which comprises (a) at least one nitro group, and/or pyridine group, and/or phenolic hydroxyl group; and (b) at least one group selected from a phosphorous-containing group and/or a carboxylic acid group, wherein the at least one phosphorous-containing group is selected from a phosphate, a phosphite, or a non-nitrogen substituted phosphonate.

Description

METHOD OF STABILIZING METAL PIGMENTS AGAINST GASSING

The present invention relates to polymer compounds useful as composite corrosion inhibitors or hydrolysis inhibitors and surface improvers for metal flake pigments. The invention also relates to coating compositions containing the treated metal pigments.

The use of metal flake pigments, such as aluminum flake pigments, to obtain coatings exhibiting a metallic effect in decorative coatings is broad. Metallic effects are particularly popular with consumers in the automotive market where a "glamour finish" is required.

Automotive coatings may utilize one uniformly colored layer. Alternatively, automotive coatings may have two distinct layers, a first highly colored layer (basecoat, basecoat) and a continuously applied coating layer (clearcoat) with little or no coloring. Two-layer coatings are known in the art as "basecoats / clearcoats." Basecoat / clearcoat coatings provide high levels of gloss and color depth that can result in particularly attractive appearance. Metal flake pigments are typically incorporated into basecoat compositions.

Waterborne automotive paints have a wide range of uses in the automotive industry due to interest in the release of organic solvents during coating application and curing processes. However, waterborne paints have the disadvantage of using a medium that can corrode metal flake pigments. For example, hydrolysis of the metal pigment may occur in an aqueous paint. Incidentally, the pH of the representative waterborne acrylic coating composition can range from 8.0 to 9.0, and the representative polyurethane coating composition can typically have a pH in the range from 7.5 to 8.0. In a basic pH environment, aluminum pigments can be oxidized. Such oxidation can be in the form of corrosion that destroys the metallic coloring properties of the enantioparticles. When coating paints with oxidized metal flake pigments on a substrate, these coatings exhibit discoloration and reduced metal effects.

Incidentally, hydrolysis or oxidation of the metal surface in the water-based paint causes the release of hydrogen gas. The amount of hydrogen gas released represents the amount of oxidation (ie, corrosion) of the metal pigment. If the coating composition is stored in a closed container, hydrogen gas may be stored under pressure.

Hydrolysis of the aluminum pigment in the presence of water can be accelerated beyond the prescribed time due to continuous contact with the basic pH environment of the coating composition. Coating compositions containing metal flake pigments can sometimes be stored for at least six months before application, which can cause severe pigment corrosion. If left unchecked for such corrosion, the coating composition becomes unusable.

Industrially, considerable efforts have been made to treat or “passivate” metal pigment surfaces to inhibit corrosion of metal surfaces by water in aqueous compositions. For example, it is known to apply a chromium coating on the surface of an aluminum pigment to suppress the corrosion and hydrogen evolution mentioned above. However, chromium can be toxic, and therefore special handling and disposal procedures are required for such chromium coated metal pigment particles.

Accordingly, it is advantageous to provide a coating composition that can be used to passivate metal pigments while completely reducing or eliminating at least some of the problems associated with known passivation procedures.

Summary of the Invention

In one embodiment, the present invention relates to a polymer suitable for passivating a metal surface. Such polymers include (a) one or more nitro groups, and / or pyridine groups, and / or phenolic hydroxyl groups; And (b) a phosphorus-containing group, wherein the phosphorus-containing group is selected from phosphates, phosphites or non-nitrogen substituted phosphonates, and / or one or more groups selected from carboxylic acid groups.

The invention also provides a passivated metal pigment comprising a passivating material formed on at least one metal pigment particle and at least a portion of the at least one pigment particle. At this time, the passivating material may comprise (a) one or more nitro groups, and / or pyridine groups, and / or phenolic hydroxyl groups; And (b) a polymer comprising at least one group selected from a phosphorus-containing group, wherein the phosphorus-containing group is selected from phosphates, phosphites or non-nitrogen substituted phosphonates, and / or carboxylic acid groups. have.

In another embodiment, the present invention is directed to a coating composition comprising one or more metal pigment particles that have been at least partially treated with a dilution medium, a deposition polymer, and a passivating material. At this time, the passivating material may comprise (a) one or more nitro groups, and / or pyridine groups, and / or phenolic hydroxyl groups; And (b) a polymer comprising at least one group selected from a phosphorus-containing group, wherein the phosphorus-containing group is selected from phosphates, phosphites or non-nitrogen substituted phosphonates, and / or carboxylic acid groups. have.

Another embodiment provides a coating composition comprising an aqueous dilution medium, a deposition polymer, and one or more metal pigment particles that have been at least partially treated with a passivating material. At this time, the passivating material may include diglycidyl ether of polyhydric alcohol; Nitro group-containing compounds selected from one or more alkyl, aryl and / or alkyl aryl nitro group-containing compounds; And a reaction product of a phosphite group-containing compound comprising a phosphate group and / or a non-nitrogen substituted phosphonate group.

Also provided is a method of passivating a metal surface, including contacting the metal surface with a passivating material. At this time, the passivating material may comprise (a) one or more nitro groups, and / or pyridine groups, and / or phenolic hydroxyl groups; And (b) a polymer comprising at least one group selected from phosphorus-containing groups, wherein the phosphorus-containing group is selected from phosphates, phosphites or non-nitrogen substituted phosphonates, and / or carboxylic acid groups. .

As used herein, all numbers indicating dimensions, physical properties, process factors, amounts of ingredients, reaction conditions, etc., as used in the specification and claims are to be modified in all instances by the term "about." It must be understood. Accordingly, unless stated otherwise, all numerical values set forth in the following specification and claims are approximations that may vary depending upon the desired properties contemplated to be obtained by the present invention. While not wishing to be limited to the principles equivalent to at least the scope of the claims, each numerical value should be understood in terms of the number of reported significant numerical values and the conventional peripheral technique applied. Moreover, all ranges disclosed herein are to be understood to include the subranges encompassed by and including the beginning and ending range values. For example, the range referred to as "1 to 10" may be any and all subranges between the minimum value 1 and the maximum value 10 (including), that is, the maximum value 10 or more, starting at the minimum value 1 or more. It is to be considered to include all subranges ending in the following, for example 5.5 to 10, 3.7 to 6.4 or 1 to 7.8 and the like. As used herein, molecular weights, whether Mn or Mw, are values that can be measured from gel permeation chromatography using polystyrene as a standard. Also, as used herein, the term "polymer" includes oligomers, homopolymers and copolymers. The terms "surface modification" and "surface modified" include any and all combinations, interactions or reactions between metal surfaces and compounds or compositions according to the disclosed invention. The terms “passivate” and “passivation” refer to modifying the surface so that the surface is less prone to corrosion and / or hydrogen gas when contacted with water. All reference numbers referred to herein are to be understood as being incorporated by reference in their entirety. As used herein, the term "non-nitrogen substituted phosphonate" refers to a group of formula (I):

Where

R ₁ is any group that does not contain nitrogen.

Passivating materials useful in the present invention generally include polymers having two or more substituents. In one non-limiting embodiment, the first substituent can include one or more nitro groups, and / or one or more pyridine groups, and / or one or more phenolic hydroxy groups. The second substituent may comprise one or more phosphorus-containing groups and / or one or more carboxylic acid groups.

In a broad implementation of the invention, the passivating polymer may be a straight chain or branched polymer. Such polymers may be, for example, acrylic polymers, polyester polymers, polyurethane polymers, epoxy polymers, polyolefin polymers, polyether polymers, or may be derived from them, or copolymers containing one or more such polymers. Can be. In one embodiment, the polymer may be a hydroxyl group- or epoxy group-containing polymer, including addition polymers and condensers, or may be derived from them, or mixtures of such polymers may also be used. Such polymers have a hydroxyl equivalent weight in the range of 100 to 1000, for example 200 to 400; Or epoxy equivalents in the range from 100 to 2000, for example from 300 to 600.

Examples of hydroxyl group-containing polymers that can be used include, but are not limited to, hydroxyl group-containing condensates such as hydroxyl functional polyesters. Examples of epoxy group-containing polymers that can be used include epichlorohydrin or dichlorohydrin and aliphatic and cycloaliphatic alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol , Dipropylene glycol, tripropylene glycol, propane diol, butane diol, pentane diol, glycerol, 1,2,6-hexanetriol, pentaerythritol and 2,2-bis (4 Polyglycidyl ethers of polyhydric alcohols, such as reaction products with -hydroxycyclohexyl) propane.

Examples of hydroxyl or epoxy group-containing addition polymers that may be used include hydroxyl or epoxy functional polymers or copolymers of ethylenically unsaturated monomers. Examples of suitable monomers having hydroxyl functional groups include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate and allyl alcohol. Examples of suitable monomers having epoxy functional groups include glycidyl (meth) acrylates. The addition polymer may be a homopolymer of any of these hydroxyl or epoxy functional monomers, or one or more of these hydroxyl or epoxy functional monomers and one or more other ethylenically unsaturated monomers that are not hydroxyl or epoxy functional It may be a copolymer of. Examples of such other monomers include, but are not limited to, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, styrene, and vinyl monomers such as styrene, vinyl toluene, and vinyl acetate. It doesn't happen.

Examples of epoxy compounds that can be used include simple compounds such as ethylene oxide, propylene oxide, butylene oxide, cyclohexene oxide and the like.

Examples of epoxy compounds that can be used also include epoxy polyethers obtained by reacting epihalohydrin with polyphenols (such as epichlorohydrin or epibromohydrin) in the presence of an alkali. Suitable polyphenols include the following: 2,2-bis (4-hydroxyphenyl) propane (ie bisphenol-A), 1,1-bis (4-hydroxyphenyl) isobutane, 2,2- Bis (4-hydroxy-t-butylphenyl) propane, 4,4-dihydroxybenzophenone, 1,1-bis (4-hydroxyphenyl) ethane, bis (2-hydroxynaphthyl) methane, 1 , 5-dihydroxynaphthalene, 1,1-bis (4-hydroxy-3-allylphenyl) ethane, and hydrogenated derivatives of these compounds. For example, polyglycidyl ethers of polyphenols of various molecular weights may be produced by varying the molar ratio of epichlorohydrin to polyphenols in a known manner.

Examples of epoxy compounds that can be used include polyglycidyl ethers of resorcinol, pyrogallol, hydroquinone and pyrocatechol, as well as phenylglycidyl ethers, alpha-naphthylglycidyl ethers, beta-naphthylglycides Also included are polyglycidyl ethers of mononuclear polyhydric phenols such as dill ethers and the corresponding compounds containing alkyl substituents on the aromatic ring.

Further non-limiting examples of epoxy compounds that can be used are glycidyl ethers of aromatic alcohols such as benzylglycidyl ether and phenylglycidyl ether, or epichlorohydrin or dichlorohydrin and ethylene glycol, diethylene Glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, propane diol, butane diol, pentane diol, glycerol, 1,2,6-hexanetriol, pentaerythrite Also included are polyglycidyl ethers of polyhydric alcohols such as reaction products with aliphatic and cycloaliphatic alcohols such as lititol and 2,2-bis (4-hydroxycyclohexyl) propane.

Other non-limiting examples of epoxy compounds that can be used also include polyglycidyl esters of polycarboxylic acids, such as generally known polyglycidyl esters such as adipic acid, phthalic acid, and the like. Other epoxy compounds that can be used include monoglycidyl esters of monocarboxylic acids such as glycidyl benzoate, glycidyl naphthoate, as well as monoglycidyl esters of substituted benzoic acid and naphthoic acid.

Addition polymerized resins containing epoxy groups can also be used. Such materials typically include epoxy functional monomers such as glycidyl acrylate, glycidyl methacrylate and allyl glycidyl ether, typically with styrene, alpha-methyl styrene, alpha-ethyl styrene, vinyl toluene, t-butyl styrene, acrylamide, methacrylamide, acrylonitrile, methacrylonitrile, ethacrylonitrile, ethyl methacrylate, methyl methacrylate, isopropyl methacrylate, isobutyl methacrylate Polymerizable ethylenically unsaturated monomers and / or vinyl monomers such as latex, hydroxyethyl acrylate, hydroxyethyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, isobornyl methacrylate and the like; It can be prepared by addition polymerization together.

Alternatively, the polymer backbone may comprise acrylic, urethane, polyester, alkyd or epoxy polymers or oligomers. The polymer backbone may comprise at least two or more isocyanate groups or capped or blocked isocyanate groups on the backbone when synthesized. This is accomplished by copolymerizing monomers with isocyanate or blocked isocyanate functional groups in the polymer backbone, or by reacting one or more groups (eg, hydroxyl or amino groups) on the polymer with isocyanate or blocked isocyanate functional groups. Can be. Reacting the isocyanate or blocked isocyanate functional groups with the isocyanate-reactive functional groups of the first substituent or the second substituent may form an appropriate linking group.

Representative examples of isocyanates or blocked isocyanate functional urethane backbones include urethane polymers having terminal isocyanates or blocked isocyanate functional groups. Urethane polymers can be synthesized by known techniques such as bulk polymerization or solution polymerization from polyfunctional compounds reactive with polyisocyanates and polyisocyanates, including, for example, polyols, polyamines and amino alcohols, provided that The sum of the equivalents of isocyanate groups and potential isocyanate groups used exceeds the equivalent use of the polyfunctional compound reactive with the polyisocyanate. The polyisocyanate is, for example, isophorone diisocyanate, p-phenylene diisocyanate, biphenyl 4,4'- diisocyanate, m-xylene diisocyanate, toluene diisocyanate, 3,3'-dimethyl-4 , 4'-biphenylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 2,2,4-trimethylhexane-1,6-diisocyanate, 1,3-bis -[2- (isocyanato) propyl] benzene (also known as tetramethylxylyl diisocyanate (TMXDI)), methylene bis- (phenyl isocyanate), 1,5-naphthalene diisocyanate, bis- (ai Socianate ethyl fumarate), methylene bis- (4-cyclohexyl isocyanate) and biuret or isocyanurate of any of the above materials.

Polyfunctional compounds reactive with polyisocyanates include ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, trimethylolethane, trimethylolpropane Diols, triols or alcohols of higher functional groups such as pentaerythritol, polyester polyols, polyether polyols and the like; Polyamines such as ethylene diamine and diethylene triamine; Or amino alcohols such as diethanolamine and ethanolamine.

One of the polyisocyanates or polyfunctional compounds reactive with polyisocyanates may have two or more functional groups (including blocked functional groups). The reactants can be distributed such that the polyurethane copolymer has terminal isocyanate functionality.

Representative examples of isocyanates or blocked isocyanate functional acrylics are copolymers of ethylenically unsaturated monomers containing isocyanate or blocked isocyanate groups. Such copolymers may be prepared using conventional techniques such as free radical polymerization, cationic polymerization, or anionic polymerization, for example in a batch process or a semi-batch process. For example, this polymerization can be carried out by heating ethylenically unsaturated monomers in a bulk solution or in an organic solution in the presence of a free radical source such as an organic peroxide or azo compound and, optionally, a chain transfer agent for a batch process. Or; Alternatively, the monomer and initiator (s) can be fed into the reactor heated at a controlled rate in a semi-batch process.

In one non-limiting embodiment, the first substituent can include a nitro group (NO ₂ ). Nitro substituents can be formed by reacting nitro-containing materials on isocyanate groups on the polymer backbone. Examples of materials useful for forming substituents capable of meeting the above mentioned requirements include any nitro-containing compound having isocyanate reactive groups such as hydroxy groups, amino groups, mercapto groups or oxirane groups. Useful nitro-containing compounds include alkyl, aryl or alkylaryl substituted compounds that include isocyanate reactive groups. Exemplary non-limiting nitro-containing compounds for the present invention include 2-methyl-2-nitro propanol, 2-nitro-1-propanol, 2-nitroethanol, 4-nitroaniline, 2-nitrobenzyl Alcohols, 4-nitro phenol, 2-nitrobenzoic acid, 4-nitrobenzoic acid, 2,4-dynitrobenzoic acid and / or mixtures thereof.

In another non-limiting embodiment, the first substituent can include one or more pyridine groups and / or one or more phenolic hydroxyl groups. Examples of suitable materials for forming the pyridine group include 2,6-pyridine dimethanol, 2-pyridine propanol, 3-pyridine propanol, pyridine propionic acid, isonaikotonic acid, pycolinic acid, dipycholinic acid, nicotinic acid, dyna It includes, but is not limited to, icotinic acid, syncomeric acid, isosyncomeronic acid or mixtures thereof. Examples of suitable materials for forming phenolic hydroxyl groups include polyhydroxy phenols such as gallic acid, allyl phenol, resorcinol, catechol, phloroglucinol, pyrogallol, 1,2,4-benzene triol Or mixtures thereof, but is not limited to them.

In one non-limiting embodiment, the second substituent comprises a phosphorus-containing group such as a phosphate group, a non-nitrogen substituted phosphonate group, orthophosphoric acid, an organic ester of phosphoric acid and / or a phosphite compound. For example, the phosphate compound may be of the type described in US Pat. No. 4,565,716. Organic phosphites are rather derivatives of phosphorous acid rather than phosphoric acid used to make organic phosphates. Exemplary organic phosphates are described in US Pat. No. 4,808,231.

Examples of phosphate esters that can be used in the practice of the present invention are mono- and dibutylphosphate, mono- and dipentylphosphate, mono- and dihexylphosphate, mono- and diheptylphosphate, mono- and dioctylphosphate, mono- And mono- and di-C ₄ -C ₁₈ alkyl esters such as dinonylphosphate, mono- and dihexadecylphosphate and mono- and dioctadecylphosphate; And aryl and aralkyl esters containing 6 to 10 carbon atoms in the aromatic group such as mono- and diphenylphosphate and mono- and dibenzylphosphate.

In one non-limiting embodiment, passivating polymers useful in the present invention are those of epoxy: nitro group: phosphate of 3.8 / 0.3 / 4.8 to 3.8 / 3 / 0.8 having one or more nitro group substituents and one or more phosphoric acid groups. Epoxy polymers having an equivalent ratio. In another non-limiting embodiment, the equivalent ratio of epoxy: nitro group: phosphoric acid can be 3.8 / 0.8 / 4.2 to 3.8 / 1 / 3.2.

It has been found that contacting a metal pigment with any passivating polymer as described above reduces or inhibits hydrolysis or oxidation of the pigment to completely reduce or eliminate the generation of hydrogen gas. Moreover, treatment of metal pigments with such polymers in waterborne coating compositions does not adversely affect the moisture resistance of the anhydrous film (coating) resulting from such waterborne compositions.

Exemplary waterborne coating compositions of the invention typically comprise a film-forming composition, an aqueous dilution medium, and a metal pigment at least partially treated with the passivating polymer of the invention. The tendency of the pigment to react with the aqueous medium and the released gaseous material is suppressed or reduced by incorporating an effective amount of the passivating material of the invention.

Examples of metal pigments suitable for use in the waterborne coating compositions of the invention generally include any metal pigments known to be used in colored coating compositions. Examples of these include nickel, tin, silver, chromium, aluminum-copper alloys, aluminum-zinc alloys and aluminum- as well as metal pigments such as metal flake pigments, at least partially composed of aluminum, copper, zinc, iron and / or brass. Metal pigments consisting of other malleable metals and alloys, such as magnesium alloys, are included, but are not limited to them. Moreover, the waterborne coating compositions of the present invention may also include one or more of a wide variety of other pigments generally known for use in coating compositions, such as various color-generating pigments and / or filler pigments. Examples of such pigments include metal oxides; Metal hydroxides; Metal sulfides; Metal sulfates; Metal carbonates; Carbon black; china clay; Commonly known pigments based on phthalo blue and green, organo-red and organic dyes are included, but are not limited to them.

As described above, various procedures may be used to incorporate the passivating material comprising the passivating polymer of the present invention into a coating composition, such as, but not limited to, the waterborne coating composition of the present invention. The term "waterborne" coating composition means a coating composition in which the dilution medium is mainly an aqueous medium, ie, the aqueous coating composition has little or no organic solvent. The term "substantially free of organic solvent", when present, means that the amount of organic solvent, if present, is less than 20% by weight, such as less than 10% by weight, based on the total weight of the coating composition. Eg less than 5% by weight, for example less than 2% by weight, for example less than 1% by weight. As will be appreciated by those skilled in the art, in one non-limiting embodiment of the invention, the waterborne coating composition comprises a small amount of organic solvent to enhance or require flow or level of the applied composition. It can adversely affect one or more coating properties, such as reducing the viscosity it becomes. One method of incorporating a passivating material comprising a polymer of the invention is a method of contacting a metal pigment with a passivating material prior to incorporating the pigment into the waterborne coating composition. This can be done by adding the passivating material of the present invention to a pigment paste (eg, a commercially available pigment) or it can be added in a preceding step, for example during the actual production of the pigment. Alternatively, the passivating material may be "neat", i.e., in the formation of an aqueous coating composition, for example film forming resins, metal pigments and aqueous media such as crosslinkers, cosolvents, thickeners and fillers. It can be introduced into the waterborne coating composition of the present invention by simply introducing it as an additional component during mixing with other conventional and optional constituents. Regardless of the manner in which the passivating material of the present invention is incorporated into the waterborne coating composition of the present invention, the amount of such compounds is generally used in an amount effective to reduce or eliminate the gasification of the metal pigment in the aqueous medium. For example, the amount of passivating material can range from 5% to 200% by weight, for example from 10% to 100% by weight, from 10% to 80% by weight, based on the weight of the pigment solid. Range, 15% to 50% by weight, 16% to 25% by weight.

One exemplary substantially organic solvent free coating composition of the present invention may be a thermoplastic film composition or a thermosetting composition. As used herein, the term "thermosetting composition" means that the resin is irreversibly "set" upon curing or crosslinking, wherein the polymer chains of the polymer components are bonded together by covalent bonds. do. This property is generally associated with the crosslinking reaction of composition components that are sometimes induced, for example, by heat or radiation. Hawley, Gessner G., The Condensed Chemical Dictionary, 9th Edition., Page 856 ; Surface Coatings, vol. 2, Oil and Color Chemists' Association, Australia, TAFE Educational Books (1974). Curing or crosslinking reactions may also be carried out under ambient conditions. When cured or crosslinked, the thermosetting composition does not melt when heat is applied and is insoluble in the solvent. In contrast, “thermoplastic compositions” include polymer components that can become liquid and flow when heated by being non-covalently bound and become soluble in solvents. Saunders, KJ, Organic Polymer Chemistry, pp . 41-42, Chapman and Hall, London (1973).

Exemplary coating compositions of the present invention include a dilution medium, a dendritic binder system, a passivating material comprising a polymer of the present invention, and one or more metal pigment particles. For example, the pigment particles may be at least partially treated with the passivating material of the present invention.

The dilution medium may be a solventborne dilution medium or an aqueous (eg, aqueous) dilution medium. The term "solvent system" means that the diluent material is mainly a non-aqueous material, for example an organic solvent material.

Dendritic binder systems typically comprise (a) at least one reactive functional group-containing film forming polymer and (b) at least one crosslinking agent having functional groups reactive with the functional groups of the film forming polymer.

The deposition polymer (a) may comprise any of a variety of reactor-containing polymers well known in the surface coating art, provided that the polymer is sufficiently dispersed in the dilution medium. Suitable non-limiting examples include acrylic polymers, polyester polymers, polyurethane polymers, polyether polymers, polysiloxane polymers, polyepoxide polymers, copolymers thereof and mixtures thereof. In addition, the polymer (a) may include various reactive functional groups, for example, one or more hydroxyl groups, carboxyl groups, epoxy groups, amino groups, amado groups, carbamate groups, isocyanate groups, and functional groups selected from combinations thereof. have.

For example, suitable hydroxyl group-containing polymers may include acrylic polyols, polyester polyols, polyurethane polyols, polyether polyols, and mixtures thereof.

Suitable hydroxyl and / or carboxyl group-containing acrylic polymers can be prepared from polymerizable ethylenically unsaturated monomers, typically hydroxyalkyl esters of (meth) acrylic acid and / or (meth) acrylic acid and (meth) acrylic acid. Alkyl esters of one or more other polymerizable ethylenically unsaturated monomers such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate and 2-ethylhexyl acrylate and styrene, alpha -Copolymers with vinyl aromatic compounds such as methyl styrene and vinyl toluene.

In one embodiment of the invention, the acrylic polymer may be prepared from ethylenically unsaturated beta-hydroxy ester functional monomers as described above.

Epoxy functional groups are ethylenically unsaturated monomers polymerizable by copolymerizing oxirane group-containing monomers such as glycidyl (meth) acrylate and allyl glycidyl ether with other polymerizable ethylenically unsaturated monomers as discussed above. It can be incorporated into acrylic polymers prepared from. Methods of making such epoxy functional acrylic polymers are described in columns 3-6 of US Pat. No. 4,001,156.

Carbamate functional groups are incorporated into acrylic polymers prepared from polymerizable ethylenically unsaturated monomers, for example, by copolymerizing the aforementioned ethylenically unsaturated monomers with carbamate functional vinyl monomers, such as carbamate functional alkyl esters of methacrylic acid. You can. Useful carbamate functional alkyl esters can be prepared, for example, by reacting hydroxyalkyl carbamate with methacrylic anhydride, such as the reaction product of ammonia and ethylene carbonate or propylene carbonate. Other useful carbamate functional vinyl monomers include, for example, reaction products of hydroxyethyl methacrylate, isophorone diisocyanate and hydroxypropyl carbamate; Or reaction products of hydroxypropyl methacrylate, isophorone diisocyanate and methanol. Another carbamate functional vinyl monomer may be used, such as the reaction product of isocyanic acid (NHCO) with hydroxyethyl acrylate and hydroxyl functional acrylic or methacrylic acid monomers as described in US Pat. No. 3,479,328. It may be. In addition, the carbamate functional group can be incorporated into the acrylic polymer by reacting the hydroxyl functional acrylic polymer with a low molecular weight alkyl carbamate such as methyl carbamate. Pendant carbamate groups can also be incorporated into the acrylic polymer by a "carcarmoyl exchange reaction" where the hydroxyl functional acrylic polymer is reacted with a low molecular weight carbamate derived from an alcohol or glycol ether. In this reaction, the carbamate group is exchanged with the hydroxyl group to give the carbamate functional acrylic polymer and the original alcohol or glycol ether. The hydroxyl functional acrylic polymer may also be reacted with isocyanic acid to provide pendant carbamate groups. Similarly, the hydroxyl functional acrylic polymer may be reacted with urea to provide pendant carbamate groups.

Polymers prepared from polymerizable ethylenically unsaturated monomers are those skilled in the art in the presence of suitable solvents such as organic peroxides or azo compounds, such as benzyl peroxide or N, N-azobis (isobutyronitrile). It may be prepared using a solution polymerization technique well known to the art. Such polymerization can be carried out in an organic solution in which the monomers are dissolved by conventional techniques in the art. Alternatively, such polymers can be prepared by aqueous emulsion polymerization or dispersion polymerization techniques well known in the art. The proportion of reactants and the reaction conditions are chosen such that an acrylic polymer with the desired pendant functionality is produced.

Polyester polymers are also useful in the film forming compositions of the present invention. Useful polyester polymers typically include condensation products of polyhydric alcohols and polycarboxylic acids. Suitable polyhydric alcohols may include ethylene glycol, neopentyl glycol, trimethylol propane and pentaerythritol. Suitable polycarboxylic acids may include adipic acid, 1,4-cyclohexyl dicarboxylic acid, and hexahydrophthalic acid. In addition to the polycarboxylic acids mentioned above, functional equivalents of acids such as anhydrides or lower alkyl esters of acids such as methyl esters may be used, if present. In addition, small amounts of monocarboxylic acids such as stearic acid may also be used. The proportion of the reactants and the reaction conditions are chosen such that a polyester polymer having the desired pendant functional groups, ie carboxyl or hydroxyl functional groups, is produced.

For example, hydroxyl group-containing polyesters can be prepared by reacting anhydrides of dicarboxylic acids such as hexahydrophthalic anhydride with a diol such as neopentyl glycol in a 1: 2 molar ratio. If improved air drying is desired, suitable dry oil fatty acids may be used, examples of which include linseed oil, soybean oil, tall oil, dehydrated castor oil or tung oil.

Carbamate functional polyesters can be prepared by first forming hydroxyalkyl carbamate that can react with the polyacids and polyols used to form the polyester. Alternatively, the terminal carbamate functional group can be incorporated into the polyester by reacting the isocyanic acid with the hydroxy functional polyester. Carbamate functional groups can also be incorporated into the polyester by reacting the hydroxyl polyester with urea. Additionally, carbamate groups can be incorporated into the polyester by carbamoyl exchange reactions. Suitable methods for preparing carbamate functional group-containing polyesters are described in columns 40 through 9 of column 4 of US Pat. No. 5,593,733.

Polyurethane polymers containing terminal isocyanate groups or hydroxyl groups can also be used as polymers in the coating compositions of the invention. Polyurethane polyols or NCO-terminated polyurethanes that can be used are those prepared by reacting polyols, including polymeric polyols, with polyisocyanates. Polyureas containing terminal isocyanate groups or primary and / or secondary amine groups, which may also be used, are those prepared by reacting polyamines, including polymeric polyamines, with polyisocyanates. The hydroxyl / isocyanate or amine / isocyanate equivalent ratio is adjusted so that the desired end group is obtained and the reaction conditions are selected. Examples of suitable polyisocyanates include those described between row 26 of column 5 to row 28 of column 6 of US Pat. No. 4,046,729, which is incorporated herein by reference. Examples of suitable polyols include those described between row 52 of column 7 to row 35 of column 10 of US Pat. No. 4,046,729. Examples of suitable polyamines include those described between rows 61 to 32 of column 7 of US Pat. No. 4,046,729 and between rows 13 to 50 of column 3 of US Pat. No. 3,799,854.

Carbamate functional groups can be incorporated into polyurethane polymers by reacting polyisocyanates with polyesters having hydroxyl functional groups and containing pendant carbamate groups. Alternatively, the polyisocyanates can be reacted with polyester polyols and hydroxyalkyl carbamate or isocyanic acid as separate reactants to produce polyurethanes. Examples of suitable polyisocyanates include aromatic isocyanates such as 4,4'-diphenylmethane diisocyanate, 1,3-phenylene diisocyanate and toluene diisocyanate, and 1,4-tetramethylene diisocyanate and 1,6-hexa Aliphatic polyisocyanates such as methylene diisocyanate. Alicyclic diisocyanates such as 1,4-cyclohexyl diisocyanate and isophorone diisocyanate can also be used.

Examples of suitable polyether polyols include polyalkylene ether polyols such as those having the following formulas I or II:

(I)

(Ⅱ)

In the above formulas,

Substituent R is hydrogen or a lower alkyl group containing 1 to 5 carbon atoms, including mixed substituents,

n typically has a value ranging from 2 to 6,

m has a value ranging from 8 to 100 or more.

Examples of polyalkylene ether polyols include poly (oxytetramethylene) glycol, poly (oxytetraethylene) glycol, poly (oxy-1,2-propylene) glycol and poly (oxy-1,2- Butylene) glycols.

Polyols formed from oxyalkylation of various polyols, for example glycols such as ethylene glycol, 1,6-hexanediol, bisphenol A, or the like, or other higher polyols such as trimethylolpropane, pentaeratritol, etc. Ter polyols are also useful. Polyols with higher functional groups that can be used as indicated can be prepared, for example, by oxyalkylation of compounds such as sucrose or sorbitol. One commonly used oxyalkylation method is a process in which a polyol is reacted with an alkylene oxide, such as propylene oxide or ethylene oxide, in the presence of an acidic catalyst or a basic catalyst. Specific examples of polyethers include children. DuPont de Nemoir & Co., Inc., those sold under the trade names TETRAHANE and TEACOL by E. I. Du Pont de Nemours and Company, Inc.

As mentioned above, in certain embodiments of the present invention, the film forming composition also optionally comprises (b) a polymer and / or any of the above mentioned polymeric microparticles, which are provided for curing the film forming composition; And / or one or more crosslinkers suitable for reacting with the functional groups of the additive. Non-limiting examples of suitable crosslinkers, provided that the crosslinker (s) are suitable to be water soluble or water dispersible, as described below, include any aminoplast and polyisocyanate as is well known in the art of surface coatings. , And their polyacids, polyanhydrides, and mixtures thereof. If used, the crosslinker or mixture of crosslinkers is selected according to the functional groups associated with the polymeric microparticles, such as hydroxyl and / or carbamate functional groups. For example, when the functional group is hydroxyl, the hydrophilic crosslinker may be an aminoplast or polyisocyanate crosslinker.

Examples of aminoplast resins suitable for use as crosslinkers include those containing a methylol group or a similar alkylol group whose portion is etherified by reaction with a lower alcohol such as methanol to provide a water soluble / water dispersible aminoplast resin. do. One suitable aminoplast resin is Cymel 385, a partially methylated aminoplast resin commercially available from Cytec Industries, Inc. Examples of blocked isocyanates that are water soluble / water dispersible and suitable for use as crosslinkers are dimethylpyrazole blocked hexa commercially available as BI 7986 from Baxenden Chemicals, Ltd., Lancashire, UK. Methylene diisocyanate trimers.

Polyacid crosslinkable materials suitable for use in the present invention contain, for example, at least one acid group, sometimes at least three and sometimes at least four acid groups, which on average are generally reactive with an epoxy functional film-forming polymer per molecule. It may include things to do. The polyacid crosslinkable material may have two, three or more functional groups. Suitable polyacid crosslinkable materials that can be used include, for example, acrylic polymers, polyesters, and carboxylic acid group-containing oligomers, polymers and compounds such as polyurethanes and compounds having phosphorus-based acid groups.

Examples of suitable polyacid crosslinkers include, for example, half-esters formed from the reaction of polyols and cyclic 1,2-acid anhydrides or acid functional polyesters derived from polyols and polyacids or anhydrides. Including ester group-containing oligomers and compounds. Such semi-esters are relatively low molecular weight and very reactive with epoxy groups. Suitable ester group-containing oligomers include those described in column 26 of column 4 to row 5 of column 5 of US Pat. No. 4,764,430, which is incorporated herein by reference.

Other useful crosslinkers include acid-functional acrylic crosslinkers prepared by copolymerizing methacrylic acid and / or acrylic acid monomers with other ethylenically unsaturated copolymerizable monomers as polyacid crosslinkable materials. Alternatively, the acid-functional acrylic can be prepared by reacting the hydroxy-functional acrylic with cyclic anhydride.

According to certain embodiments of the invention, the crosslinking agent (b), which is typically water soluble / water dispersible, is from 0 to at least 10% by weight, based on the total weight of resin solids in the film forming composition as one component of the film forming composition, or It may be present in an amount ranging from at least 10% to at least 20%, or at least 20% and at least 30% by weight. According to certain embodiments of the invention, the crosslinking agent is one component of the film forming composition and is 70% by weight or less to 60% by weight or alternatively 60% by weight or less based on the total weight of the resin solids in the film forming composition. It may be present in an amount ranging from up to 50%, or up to 50% by weight or less. The crosslinker may be present in an amount in the range between any combination of the values included in the ranges mentioned.

The dendritic binder for the basecoat can be an organic solvent-based material such as those described over column 24 of column 2 to column 40 of column 4 of US Pat. In addition, waterborne coating compositions as described in US Pat. Nos. 4,403,003, 4,147,679 and 5,071,904 may also be used as binders in basecoat compositions.

The coating composition may comprise various other components generally known for use in waterborne coating compositions. Examples of such various other ingredients include: fillers; Plasticizers; Antioxidants; Powdery mildew and fungicides; Surfactants; For example, thixotropes and precipitated silicas, fumed silicas, organic-modified silicas, bentone clays, organic-modified benton clays and for example US Pat. No. 4,025,474; No. 4,055,607; No. 4,075,141; No. 4,115,472; No. 4,147,688; No. 4,180,489; No. 4,242,384; No. 4,268,547; No. 4,220,679; And various flow control agents including additives for sag resistance and / or pigment orientation, such as additives based on polymer particulates (sometimes referred to as microgels) described in US Pat. No. 4,290,932.

Examples of organic solvents and / or diluents that can be used in the organic solvent-based coating compositions of the present invention include methanol, ethanol, n-propanol, isopropanol, butanol, s-butyl alcohol, t-butyl alcohol, amyl alcohol, hexyl alcohol And alcohols such as lower alkanols containing 1 to 8 carbon atoms, including 2-ethylhexyl alcohol; Ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol dibutyl ether, propylene glycol monomethyl ether, diethylene glycol monobutyl ether, diethylene glycol dibutyl ether, Ethers and ether alcohols such as dipropylene glycol monomethyl ether and dipropylene glycol monobutyl ether; Ketones such as methyl ethyl ketone, methyl isobutyl ketone, methyl amyl ketone and methyl N-butyl ketone; Esters such as butyl acetate, 2-ethoxyethyl acetate and 2-ethylhexyl acetate; Aliphatic and cycloaliphatic hydrocarbons such as various petroleum naphtha and cyclohexane; And aromatic hydrocarbons such as toluene and xylene. The amount of organic solvent and / or diluent used in the organic solvent-based coating composition of the present invention can vary widely. However, in one non-limiting embodiment, the amount of organic solvent and / or diluent can range from about 10 to about 50 weight percent, such as 20 to 40 weight percent, based on the total weight of the organic solvent based coating composition. .

The passivating materials of the present invention can also be used in powder coating compositions comprising film-forming polymers and pigments (typically metal pigments).

The following examples illustrate the invention and should not be understood as limiting the scope of the invention. It should be understood that all percentages and amounts are by weight unless otherwise indicated.

The following examples illustrate the gasification characteristics of an exemplary coating composition incorporating a passivating material comprising a polymer of the present invention as compared to a commercially available passivating material.

Preparation of Passivating Material

Polymers for use in the passivating materials of the invention and compositions incorporating such polymers were prepared as follows:

Polymer Synthesis Example 1 (PE1)

The passivating polymer of the present invention was prepared from the following components as described below.

The first three components were charged to the reactor, heated to a temperature of 100 ° C. under nitrogen, and held at that temperature for about 1 hour. The reaction mixture was cooled to 30 ° C. and then component 4 was added. The reaction temperature was then raised to 100 ° C. and then the mixture was held at that temperature for approximately 2 hours. The product thus formed was then diluted with components 5, 6 and 7 with stirring. The product was cooled to room temperature. The reaction product had a solids content of about 32% and a pH of 5.7.

Polymer Synthesis Example 2 (PE2)

The polymer was prepared as same as that of Example 1 but with 2-nitrophenol replaced by 4-nitrobenzoic acid on an equivalent basis.

Polymer Synthesis Example 3 (PE3)

The polymer was prepared as same as the polymer of Example 2 but by replacing half (1/2) of 4-nitrobenzoic acid with isonicotinic acid on an equivalent basis.

Polymer Synthesis Example 4 (PE4)

The polymer was prepared as same as that of Example 2 but with 4-nitrobenzoic acid replacing isonicotinic acid on an equivalent basis.

Polymer Synthesis Example 5 (PE5)

The polymer was prepared by replacing all EPON 828 with only 4-nitrobenzoic acid, which was the same as the polymer of Example 2. Phosphoric acid was not used at all.

Polymer Synthesis Example 6 (PE6)

The polymer was prepared as same as the polymer of Example 2 by replacing 42% by weight phosphoric acid with trimellitic anhydride on an equivalent basis.

Polymer Synthesis Example 7 (PE7)

A polymer was prepared by replacing 50 equivalents of 4-nitrobenzoic acid as the polymer of Example 2 with the reaction product of phthalic anhydride and hydroxyethylethylene urea (prepared by reacting these two components at 120 ° C.). .

Polymer Synthesis Example 8 (PE8)

The polymer was prepared as same as that of Example 2 but with 4-nitrobenzoic acid replacing isostearic acid on an equivalent basis.

Polymer Synthesis Example 9 (PE9)

The polymer was prepared by replacing EPON 828 with EPON 872 (epoxy equivalent 645) on the equivalent basis, but with the polymer of Example 8.

Polymer Synthesis Example 10 (PE10)

Polyurethane acrylate was prepared from the following components as described below:

The first four components were stirred in the flask with HDI added over 1 hour at a temperature between 70 ° C. and 80 ° C. The addition funnel was then washed with 39 g of butyl acrylate and then the temperature of the reaction mixture was maintained at 70 ° C. for an additional 2 hours until all isocyanates reacted. The remaining butyl acrylate was then added to prepare an 80% solution with Gardner-Holdt viscovity of X.

A pre-emulsion was prepared from the following components:

The pre-emulsion was passed once through the M110 MICROFLUIDIZER RTM emulsifier at 7000 psi to prepare a microdispersion. The microdispersion was stirred at 22 ° C. under nitrogen in a round bottom flask, and then the ingredients listed in Table 4 were added.

When the components of Table 4 were added, the reaction temperature naturally rose to 56 ° C. after approximately 15 minutes. The final product had the following characteristics:

Total solids content of about 42% by weight;

PH of about 8.3; And

Brookfield viscosity of about 14 cps (50 rpm, spindle # 1).

Polymer Example 11 (PE11)

This example describes a method for producing an acrylic polyester polymer. Acrylic polymers were prepared from the following components as described below.

Polyester (P): Polyester was prepared in a four-neck round bottom flask equipped with a thermometer, a mechanical stirrer, anhydrous nitrogen sparger and a heating mantle. Polyesters were prepared from the components listed in Table 5 below.

The first six components were stirred at 230 ° C. in the flask. The distillate was collected in a Dean Stark trap and then the mixture was kept at that temperature until the acid value dropped below 5. The product was then cooled to a temperature below 80 ° C. and then diluted with butyl acrylate.

Polyester / acrylic latex manufacturer

The following components were stirred together to prepare a pre-emulsion:

The pre-emulsifier was once passed through a MICROFLUIDIZER RTM M110T at 8000 psi and then transferred to a four-necked round bottom flask under a nitrogen atmosphere equipped with an overhead stirrer, condenser and thermometer. 150.0 g of deionized water used to wash the MICROFLUIDIZER RTM was added to the flask. 4.0 g of 70% t-butyl hydroperoxide) added to 4.0 g of isoascorbic acid and 0.02 g of ferrous ammonium sulfide dissolved in 120.0 g of water and then dissolved in 115.0 g of water over 30 minutes Was added to initiate the polymerization. When the temperature was reduced to 28 ° C., 36 g of 33.33% aqueous dimethylethanolamine were added followed by 2.0 g of PROXEL GXL (biocide commercially available from ICI Americas, Inc.) in 8.0 g of water. It was. The latex thus formed had a pH of 7.9, a nonvolatile content of 42.0%, and a Brookfield viscosity of 17 cps (spindle # 1, 50 rpm).

Polymer Example 12 (PE12)

This example describes a method for producing an acrylic dispersion. Acrylic dispersions were prepared from the components listed in Table 7 as described below.

Fill # 1 was added to a reactor equipped with a thermocouple, stirrer and reflux condenser. The reactor contents were heated to a temperature of 80 ° C. Feeds A and B (step I) were then added to the reactor over 3 hours and the reaction mixture was stirred at a temperature of 80 ° C. for 30 minutes. Feeds C and D (step II) were then added over 30 minutes and then stirred at 80 ° C. for 30 minutes. At this time, feeds E and F (Step III) were added over 30 minutes, stirred for 1 hour and then cooled to ambient temperature. Feed G was then added over 5 minutes and then stirred for at least 10 minutes.

Polymer Example 13 (PE13)

This example describes the preparation of a polymer having the following components:

The reactor was charged with the first seven components and then heated to 80 ° C. under nitrogen until the mixture was homogeneous. After cooling to 55 ° C., premixed components 8 and 9 were added over 30 minutes. The mixture was exothermic to 90 ° C. or less. The mixture was then maintained at that temperature until the isocyanate equivalent weight was about 1370. Then premixed components 10, 11 and 12 were added. The product was stirred for an additional 30 minutes and then cooled to room temperature. The final product had a total nonvolatile component content of 24% and a viscosity of less than 100 centipoise (cp).

Preparation of Aqueous Composition

Base Coat Example BC1-10

An aqueous silver based metallic basecoat composition was prepared containing the passivating agents of Examples 1-10. For each basecoat composition (Example BC1-10 below), aluminum pigment slurry, Premix A1-10, respectively, it was prepared from the following ingredients primarily as described below. The amounts listed below are parts by weight (g). The premix A1-10 components were mixed with gentle stirring and then stirred for 30 minutes until the mixture was well dispersed. Premix A1 used commercially available passivating material (LUBRIZOL 2062, available from Lubrizol Company).

Basecoat compositions (Examples BC1 to BC10) were prepared from the following components as described below. Amounts listed below are parts by weight unless otherwise indicated. Basecoat composition BC1 was used as a control and contained commercially available passivating material.

The components listed above were mixed with stirring to prepare the respective aqueous basecoat compositions of Examples BC1 to BC10. The pH of each composition was adjusted to 8.4-8.6 with an appropriate amount of 50% aqueous solution of DMEA. After 16 hours of equilibration at ambient conditions, the pH of each basecoat was adjusted to 8.4-8.6 with an appropriate amount of 50% aqueous solution of DMEA. Deionized water was then used to reduce the viscosity of each composition to a spray viscosity of 24 to 26 seconds (Ford # 4 cup). Subsequently, a gasification test was performed on the sample as described below.

Gasing Evaluation

Each of the aqueous basecoat compositions of Examples BC1 to BC10 was evaluated to determine the amount of gas released from the aluminum flake-containing waterborne coating. The test method was used to measure the effect of aluminum flake passivating agents (ie, gasification inhibitors) on stopping or inhibiting the reaction between hydrogen gas and heat generating aluminum pigment surfaces and water. Such test methods include loading aluminum flake-containing waterborne paint into a gasification laboratory and measuring the amount of gas released in ml of gas released per 200 g of basecoat composition over 7 days.

After the pH and viscosity are finally adjusted as described above, 200 g of each basecoat composition is placed in a separate 250 ml Erlenmeyer flask and greased with a hose connector (Tygon tubing). It was capped with a greased glass adapter. A taper clip was attached to the flask and adapter connection. A lead weight was placed around each filled Elenmeyer flask and then each of them was placed in a preset 40 ° C. thermostat. The temperature was then equilibrated in a thermostat for 4 hours.

While equilibrating the composition, the ring stand and burette were assembled into a Naalgene tub located after the thermostat. The ring stand was placed in a watertight bucket filled with water. The burette clamp was attached to the ring stand. For each basecoat, 250 ml burettes were filled with water and then turned upside down in a water filled vat. The flipped burette was positioned so that the top of the flipped burette lies below the top of the water surface in the bucket. The burette was clamped in place using a burette clamp.

After the equilibration period elapsed, the Tygon tubing was inserted into the inverted burette and then attached to the end of the hose adapter on the flask inside the thermostat. The initial water level (ml) in the burette was then recorded. The difference between the initial water level in the test apparatus and the final water level after 7 days was recorded as the amount of gas released from the basecoat. As will be appreciated by those skilled in the art, gasification results may differ from one run to another due to subtle differences in experimental conditions. Therefore, it should be understood that the gasification results in Table 11 have a tolerance of about ± 5 ml.

The results shown in Table 11 below are compared to the passivating agents (Example BC1) in which an aqueous metallic basecoat composition (ie, compositions of Examples BC2 to BC14) containing the aluminum passivating agent of the present invention is commercially available. To illustrate similar or improved aluminum flake passivation.

Basecoat Examples BC11 to BC13

Examples BC11 to BC13 below describe a process for the preparation of an aqueous silver based metallic basecoat composition. For each of the basecoat compositions, aluminum pigment slurries, and premix A11-13 of Examples BC11 to BC13, respectively, were prepared from the following components, as described below, primarily. The amounts listed below are parts by weight (g). The premix A11-13 components were mixed with stirring and then stirred for 30 minutes until the mixture was well dispersed. Premix A11 used a commercially available passivating material (LUBRIZOL 2062, available from Lubrizol Company).

Aqueous basecoat composition

Each aqueous basecoat composition of Examples BC11-BC13 was then prepared from the following components as described below. Amounts listed below are parts by weight (g) unless otherwise indicated.

The components listed above were mixed with stirring to prepare the respective aqueous basecoat compositions of Examples BC11-13. The pH of each composition was adjusted to 8.4-8.6 with an appropriate amount of 50% aqueous solution of DMEA. Deionized water was then used to reduce the viscosity of each aqueous basecoat composition to 33-37 seconds spray viscosity (DIN # 4 cup).

Gasification evaluation

Each of the aqueous basecoat compositions of Examples BC11 to BC13 was evaluated according to the gasification assay described above for Examples BC1 to BC10.

The results shown in Table 14 below show a control passive containing a passivating material in which an aqueous metallic basecoat composition containing the aluminum passivating agent of the present invention (ie, the compositions of Examples BC12 to BC13) is commercially available. It is illustrated that it provides a similar or improved aluminum flake passivation compared to the tingting agent (ie, the composition of Example BC11).

Examples BC14 to BC17

Examples BC14 to BC17 below describe the preparation of aqueous silver based metallic basecoat compositions each containing the passivating agents of Examples A14 to A17 in Table 15 below. For each of the basecoat compositions, aluminum pigment slurries, and premix A14-17 of Examples BC14 to BC17, respectively, were prepared from the following components, as described first below. The amounts listed below are parts by weight (g). The premix A14-17 components were mixed with stirring and then stirred for 30 minutes until the mixture was well dispersed.

As shown in Table 15 below, premixes 14, 16 and 17 contained known passivating materials, while premix 15 contained the passivating materials of the present invention. The premixes in Table 15 below all contain 15% by weight of the passivating agent of the present invention based on the weight% of the aluminum pigment.

Aqueous basecoat composition

Aqueous basecoat compositions (Examples BC14-BC17) were prepared as described in Table 16 below using Premix A11-A14. The amounts listed below are parts by weight (g) containing 15% by weight of passivating agent, based on the amount of aluminum pigment, unless otherwise indicated.

The components listed above were mixed with stirring to prepare the respective aqueous basecoat compositions of Examples BC14 to BC17. The pH of each composition was adjusted to 8.4-8.6 with an appropriate amount of 50% aqueous solution of DMEA. After 16 hours of equilibration at ambient conditions, the pH of each basecoat was adjusted to 8.4-8.6 with an appropriate amount of 50% aqueous solution of DMEA. Deionized water was then used to reduce the viscosity of each composition to a spray viscosity of 24 to 26 seconds (Ford # 4 cup). Subsequently, a gasification test was performed on the sample as described below.

Gasification evaluation

Each of the aqueous basecoat compositions of Examples BC14 to BC17 was evaluated according to a test method that measures the amount of gas released from an aluminum flake-containing waterborne coating. This test method was used to measure the effect of aluminum flake passivating agents (ie, gasification inhibitors) on stopping or inhibiting the reaction between hydrogen gas and heat generating aluminum pigment surface and water. These test methods include loading aluminum flake-containing water-based paints into a gasification laboratory and measuring the amount of gas released per 250 g of paint over 7 days (ml).

After the pH and viscosity were finally adjusted as described above, 250 g of each basecoat was placed in a gasification vessel and then placed in a 40 ° C. water bath. After each sample was placed in the bath as quickly as possible the possible gas evolution was reduced. The results are described in Table 17 below.

As can be seen from the results shown in Table 17 above, the passivating material of the present invention provided improved gasification properties over other known passivating materials.

Example 2

This example illustrates the effect of the passivating material of the present invention on the appearance properties of the coated article.

Coating compositions B15 and B18-20 were evaluated for various appearance properties as described in Table 18 below. B18, B19 and B20 are identical to B14, B16 and B17, respectively, except they contain 20 wt% passivating agent instead of 15 wt% passivating agent.

Those skilled in the art will appreciate that changes may be made without departing from the scope of the disclosure. Accordingly, it is to be understood that the specific embodiments described in detail herein are illustrative only and are not intended to limit the scope of the present invention, which belongs to the appended claims and any and all equivalents thereof.

Claims (34)

(a) one or more nitro groups, and / or pyridine groups, and / or phenolic hydroxyl groups; And (b) at least one group selected from phosphorus-containing groups and / or carboxylic acid groups, wherein the at least one phosphorus-containing group is selected from phosphates, phosphites or non-nitrogen substituted phosphonates A passivating material suitable for passivating a metal surface, comprising a polymer comprising a polymer. The method of claim 1, A passivating material wherein said polymer is selected from or derived from acrylic polymers, polyester polymers, polyurethane polymers, epoxy polymers, polyolefin polymers, polyether polymers, copolymers thereof or mixtures thereof. The method of claim 1, Passivating material wherein said polymer comprises or is derived from an epoxy polymer. The method of claim 1, Passivating material wherein the polymer is derived from the reaction product of a reactant comprising a glycidyl ether of an aromatic alcohol. The method of claim 1, Passivating material wherein the polymer is derived from the reaction product of a reactant comprising polyglycidyl ether of a polyhydric alcohol. The method of claim 1, Passivating material wherein the polymer comprises or is derived from an acrylic polymer having glycidyl functionality. The method of claim 1, Passivating material wherein the phosphorus-containing group is selected from one or more phosphate groups and / or non-nitrogen substituted phosphonate groups. The method of claim 1, Passivating material wherein the phosphorus-containing group is derived from one or more phosphoric acids, and / or alkyl, aryl and / or alkyl aryl phosphonic acids, or mixtures thereof. The method of claim 8, Passivating material wherein the phosphorus-containing group comprises one or more acid and / or ester functional groups. The method of claim 9, Passivating material wherein the acid functionality is partially or completely neutralized. The method of claim 1, Passivating material wherein said nitro group is derived from one or more alkyl, aryl and / or alkyl aryl nitro group-containing compounds. The method of claim 1, Passivating material wherein said nitro group is derived from an aromatic nitro group-containing compound selected from 2-nitrobenzoic acid, 4-nitrobenzoic acid, 2,4-dynitrobenzoic acid and mixtures thereof. The method of claim 1, Passivating material wherein said nitro group is derived from 4-nitrobenzoic acid. The method of claim 1, The polymer is an aromatic epoxy group-containing compound; Aromatic nitro compounds; And a reaction product of a reactant comprising a phosphorus-containing compound. The method of claim 1, The polymer is a diglycidyl ether of a polyvalent aromatic alcohol; Nitro compounds selected from the group consisting of 2-nitrobenzoic acid, 4-nitrobenzoic acid, 2,4-dynitrobenzoic acid and mixtures thereof; And a reaction product of a phosphorus-containing compound selected from the group consisting of phosphoric acid, alkyl, aryl and / or alkyl aryl phosphonic acids, and mixtures thereof. The method of claim 14, A passivating material in which the polymer has an equivalent ratio of epoxy: nitro group: phosphoric acid of 3.8 / 0.3 / 4.8 to 3.8 / 3 / 0.8. The method of claim 14, A passivating material in which the polymer has an equivalent ratio of epoxy: nitro group: phosphoric acid of 3.8 / 0.8 / 4.2 to 3.8 / 1 / 3.2. One or more metal pigment particles; And Passivating material comprising the polymer of claim 1, formed on at least a portion of at least one pigment particle. Passivated metal pigments comprising. The method of claim 18, Pigment in the form of metal flakes. The method of claim 18, Pigments comprising oxides or alloys wherein the metal pigment particles contain at least one of aluminum, copper, zinc, brass, nickel, tin, silver, chromium, iron and at least one of the foregoing. The method of claim 18, Pigment, wherein said pigment particles are in the form of aluminum flakes. The method of claim 18, Wherein said at least one pigment particle comprises a mixture of aluminum pigment particles and iron oxide pigment particles. (a) dilution medium; (b) film-forming polymers; And (c) at least one metal pigment particle at least partially treated with a passivating material comprising the polymer of claim 1 Coating composition comprising a. The method of claim 23, wherein The dilution medium is an aqueous dilution medium. The method of claim 23, wherein The dilution medium is a non-aqueous dilution medium. The method of claim 23, wherein Wherein said at least one metal pigment particle comprises aluminum in flake form. The method of claim 23, wherein Wherein said at least one pigment particle comprises a mixture of aluminum pigment particles and iron oxide pigment particles. (a) an aqueous dilution medium; (b) film forming polymers; And (c) diglycidyl ethers of polyhydric alcohols; Nitro group-containing compounds selected from one or more alkyl, aryl and / or alkyl aryl nitro group-containing compounds; And at least partially treated with a passivating material comprising a polymer comprising a reaction product of a phosphite group-containing compound comprising a phosphate group and / or a non-nitrogen substituted phosphonate group. Coating composition comprising a. The method of claim 28, Wherein said at least one pigment particle is in the form of a metal flake. The method of claim 28, Wherein said at least one metal pigment particle comprises an oxide or alloy containing at least one of aluminum, copper, zinc, brass, nickel, tin, silver, chromium, iron and at least one of the foregoing. The method of claim 28, Wherein said pigment particles are in the form of aluminum flakes. The method of claim 28, Wherein said at least one pigment particle comprises a mixture of aluminum pigment particles and iron oxide pigment particles. A method of passivating a metal surface, comprising contacting the metal surface with a passivating material comprising the polymer of claim 1. The method of claim 33, The metal surface comprises a pigment in the form of aluminum flakes.