Coating composition

Abstract

A coating composition comprising: a. A polyesterimide (PEI) polymer having an acid number > = 10 mg KOH / g; and b. A cross-linking agent that can be used to cross-link the acid functionality on the polyesterimide polymer; wherein the coating composition is substantially free of bisphenol A (BPA), bisphenol F (BPF), bisphenol A diglycidyl ether (BADGE), and bisphenol F diglycidyl ether (BFDGE).

Description

[0001] This application is a divisional application of the Chinese patent application with application number 201880006773.7. Technical Field

[0002] The present invention relates to a coating composition comprising a polyesterimide resin. Specifically, the present invention relates to a coating composition comprising a polyesterimide resin for application to metal substrates, particularly metal substrates used in the packaging industry, such as food and / or beverage containers or aerosol cans. Such coatings may include liquid or powder coatings, such as thermosetting powder coatings. The present invention also extends to metal substrates coated at least in part with such a coating composition, and packaging articles, such as cans, pipes, etc., having such a coating on at least a portion thereof. Background of the Invention

[0003] The surface of container such as food and / or beverage container, the container of personal care product or aerosol container needs to be coated for various reasons.The outer surface of such container is often coated in a decorative manner, and can allow printing thereon to tell the user about the information of container contents.The inner surface of such container is usually coated to protect container from content infringement wherein, and these contents can be chemically corrosive in some cases.The coating on the container also should protect content from container infringement.From the material as the product of container corrosion or from the change of the content of coating itself should be minimum.Therefore, the coating composition that is used to coat the inner surface of container should be designed, so that it can stand contact with these corrosive chemicals and make the material from the metal of container or coating to the release in container contents minimized.

[0004] A wide variety of coatings have been used to coat containers. With respect to food and / or beverage containers, the coating compositions need to have certain properties such as being able to be applied at high speeds, having excellent adhesion to the substrate, being safe for food contact and having properties when cured that are suitable for their end use.

[0005] Containers (e.g., aerosol cans) for storing aerosols, such as personal health care aerosols, or aerosols for industrial use, are typically formed from tubes, such as aluminum tubes. One such tube type is the monobloc sprayer, so called because it is formed from a single piece (a small disc called a "slug") of aluminum. Such aluminum tubes can also be formed into bottle shapes, so-called "monobloc bottles," and used, for example, for beer and other beverages. Coating compositions known in the art and used to coat such cans, particularly the interior thereof, include polyamideimides, which are manufactured in N-methylpyrrolidone. However, N-methylpyrrolidone has recently been reclassified as toxic to reproduction and development (toxic to the reproductive system) and has also been listed as having specific tissue toxicity to the respiratory tract, making its use undesirable.

[0006] In addition, many coating compositions currently used for food and / or beverage or aerosol applications contain epoxy resins. Such epoxy resins are typically formed from polyglycidyl ethers of bisphenol A (BPA). BPA is considered harmful to human health and therefore it is desirable to eliminate it from coatings. Derivatives of BPA, such as diglycidyl ethers of bisphenol A (BADGE), epoxy novolac resins and polyols prepared from BPA and bisphenol F (BPF) are also considered problematic.

[0007] It is an object of aspects of the present invention to provide a solution to one or more of the above-mentioned or other problems. Summary of the Invention

[0008] According to a first aspect of the present invention, there is provided a coating composition comprising:

[0009] a. A polyester imide (PEI) polymer having an acid value ≥10 mg KOH / g; and

[0010] b. a crosslinking agent which can be used to crosslink the acid functionality on the polyesterimide polymer;

[0011] The coating composition is substantially free of bisphenol A (BPA), bisphenol F (BPF), bisphenol A diglycidyl ether (BADGE), and bisphenol F diglycidyl ether (BFDGE).

[0012] Typically, PEI polymers contain polyester linkages and imides in the polymer backbone.

[0013] Suitably, the PEI polymer is formed by the part containing imide.The part containing imide can also include acid group and / or alcohol group.The part containing imide can include at least 2 acid groups, at least 2 alcohol groups or at least 1 acid group and at least 1 alcohol group.

[0014] The imide-containing moiety may comprise a cyclic imide group.

[0015] The imide-containing moiety can be formed as the reaction product between a primary amine or an isocyanate and a cyclic anhydride. For example, typical components in such a reaction can include a difunctional isocyanate such as methylene diphenyl diisocyanate, and an anhydride such as trimellitic anhydride.

[0016] An example of such a reaction is shown in Scheme 1 below.

[0017]

[0018] As can be seen from the above reaction scheme, the imide-containing moiety formed can be a diacid-substituted imide, which can then be reacted with a diol (eg, ethylene glycol) in a polyesterification reaction to thereby form an imide-containing polyester (polyesterimide).

[0019] An alternative example of forming an imide containing moiety is shown below in Scheme 2. Scheme 2 shows the reaction of trimellitic anhydride with bis(4-isocyanatocyclohexyl)methane to form the imide diacid.

[0020]

[0021] In another example, Scheme 3 below shows a reaction that results in the formation of an imide-containing moiety that is monoacid, monohydroxy-substituted. In this example, a primary amine, monoethanolamine, which has additional hydroxyl functionality, reacts with trimellitic anhydride to produce a cyclic imide with hydroxyl and acid functionality. The monoimide product shown in Scheme 3 can then be reacted with other diols, polyols, and diacids in a polyesterification reaction to form an imide-containing polyester (polyesterimide).

[0022] Alternatively or additionally, the reaction product of Scheme 3 may self-condense in a polyesterification reaction.

[0023]

[0024] Examples of suitable amines that can be used include diamines such as ethylenediamine; 1,3-propanediamine; tetramethylenediamine; 1,6-hexanediamine; trimethylhexane-1,6-diamine; isophoronediamine diaminodiphenylmethane (methylenedianiline); diaminodiphenyl ether; diaminodiphenyl sulfone; methylene-4'-cyclohexyldiamine; benzoguanamine; o-xylylenediamine; m-xylylenediamine; p-xylylenediamine; 1,2-cyclohexanediamine; 1,4-cyclohexanediamine; the amines may also include hydroxylamines such as monoethanolamine; monopropanolamine; or aminocarboxylic acids such as glycine; aminopropionic acid or aminobenzoic acid; and combinations thereof.

[0025] Examples of suitable isocyanates include, for example, hexamethylene diisocyanate; tetramethylene diisocyanate; isophorone diisocyanate; methylene-4,4'-bis(cyclohexyl isocyanate) or bis-(4-isocyanatocyclohexyl)methane; methylene diphenyl diisocyanate or bis-(4-isocyanatophenyl)methane; tetramethyl-m-xylylene diisocyanate; m-xylylene diisocyanate; p-xylylene diisocyanate; cyclohexane diisocyanate; naphthalene diisocyanate; trimethylhexamethylene diisocyanate; and combinations thereof.

[0026] Examples of suitable cyclic anhydrides include trimellitic anhydride; pyromellitic dianhydride; maleic anhydride; 3,3',4,4'-benzophenonetetracarboxylic dianhydride; tetrahydrophthalic anhydride; 1,4,5-naphthalenetricarboxylic anhydride; 1,4,5,8-naphthalenetetracarboxylic dianhydride; trimellitic anhydride; and combinations thereof.

[0027] The imide-containing moiety may typically be formed in the absence of a diol or polyol (i.e., less than 1 wt% diol or polyol, suitably less than 0.5 wt%, more suitably less than 0.1 wt%, for example less than 0.05 wt% or less than 0.01 wt%). The imide-containing moiety may be formed in the absence of a diol or polyol.

[0028] The imide-containing moiety can be formed in the presence of a diol or a polyol.

[0029] The polyesterimide polymer is suitably formed by reacting an imide-containing moiety with a diol, polyol (or other predominantly hydroxyl-functional branching monomer), a dicarboxylic acid, a diester or a component containing one acid group (or ester) and one alcohol group, whereby a polyester is formed, as the case may be (depending on the functionality of the imide).

[0030] As used herein, "polyol" and similar terms refer to compounds having two or more hydroxyl groups, for example, 2, 3 or 4 hydroxyl groups. The hydroxyl groups of the polyol may be linked by a bridging group selected from the group consisting of an alkylene group, an alkenylene group, an alkynylene group, or an arylene group. Suitable polyols are organic polyols.

[0031] As used herein, "diol" and similar terms refer to a compound having two hydroxyl groups. The hydroxyl groups of the diol may be connected by a bridging group selected from the group consisting of an alkylene group, an alkenylene group, an alkynylene group, or an arylene group. Suitable diols are organic polyols.

[0032] Examples of suitable diols include, but are not limited to, the following: ethylene glycol; 1,2-propylene glycol; 1,3-propylene glycol; 1,2-butanediol; 1,3-butanediol; 1,4-butanediol; 2,3-butanediol; 2-methyl-1,3-propanediol; 2,2'-dimethyl-1,3-propanediol; 1,5-pentanediol; 3-methyl-1,5-pentanediol; 1,6-hexanediol; diethylene glycol; triethylene glycol; dipropylene glycol; tripropylene glycol; 2,2,4-trimethylpentane-1,3-diol; 1,4-cyclohexanedimethanol; tricyclodecane dimethanol; 2,2,4,4-tetramethylcyclobutane-1,3-diol; isosorbide; 1,4-cyclohexanediol; 1,1'-isopropylidene-bis-(4-cyclohexanol); and combinations thereof.

[0033] Examples of suitable polyols (or other primarily hydroxyl-functional branching monomers) include, but are not limited to, the following: tris(hydroxyethyl)isocyanurate; trimethylolpropane; trimethylolethane; 1,2,6-hexanetriol; pentaerythritol; erythritol; ditrimethylolpropane; dipentaerythritol; N,N,N',N'-tetrakis(hydroxyethyl)adipic acid diamide; N,N,N',N'-tetrakis(hydroxypropyl)adipic acid diamide; tris(hydroxyethyl)amine; hexahydro-1,3,5-tris(hydroxyethyl)-s-triazine; N,N,N',N'-tetrakis-(hydroxyethyl)ethylenediamine; diethanolamine; or combinations thereof.

[0034] As used herein, "diacid" and like terms refer to a compound having two carboxylic acid groups, and include diacids (wherein the acid groups are esterified) or esters of anhydrides.The diacid is suitably an organic polyacid.

[0035] Suitably, the carboxylic acid groups of the diacid may be linked via a bridging group selected from: an alkylene group; an alkenylene group; an alkynylene group; or an arylene group.

[0036] Examples of suitable diacids include, but are not limited to, the following: isophthalic acid; terephthalic acid; 1,4-cyclohexanedicarboxylic acid; succinic acid; adipic acid; azelaic acid; sebacic acid; fumaric acid; 2,6-naphthalene dicarboxylic acid; phthalic acid. The diacids may also be used in the form of diester materials, for example, dimethyl ester derivatives such as dimethyl isophthalate; dimethyl terephthalate; dimethyl 1,4-cyclohexanedicarboxylate; dimethyl 2,6-naphthalene dicarboxylate; dimethyl fumarate; dimethyl phthalate; dimethyl succinate; dimethyl glutarate; dimethyl adipate; or combinations thereof.

[0037] As used herein, unless otherwise indicated, the term "alkane" or "alkyl" refers to a saturated hydrocarbon group that is a linear, branched, cyclic or polycyclic moiety or a combination thereof and contains 1 to 20 carbon atoms, suitably 1 to 10 carbon atoms, more suitably 1 to 8 carbon atoms, still more suitably 1 to 6 carbon atoms, still more suitably 1 to 4 carbon atoms. These groups may be optionally substituted with chloro, bromo, iodo, cyano, nitro, OR 19 、OC(O)R 20 、C(O)R 21 、C(O)OR 22 NR 23 R 24 、C(O)NR 25 R 26 SR 27 、C(O)SR 27 、C(S)NR 25 R 26 , aryl or Het, wherein R 19 to R 27 Each independently represents hydrogen, aryl or alkyl, and / or is interrupted by oxygen or sulphur atom, or is interrupted by silanyl or dialkylsiloxane.The example of such group can be independently selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 2-methylbutyl, pentyl, isopentyl, hexyl, cyclohexyl, 3-methylpentyl, octyl etc.As used in this article, term " alkylidene " relates to divalent radical alkyl defined above.For example, alkyl such as methyl (it will be expressed as-CH ) becomes methylene-CH when being expressed as alkylidene -CH .Other alkylidene should be understood accordingly.

[0038] As used herein, the term "alkenyl" refers to a hydrocarbon group having double bonds, suitably up to 4 double bonds, which is a linear, branched, cyclic or polycyclic moiety or a combination thereof, and contains 2 to 18 carbon atoms, suitably 2 to 10 carbon atoms, more suitably 2 to 8 carbon atoms, still more suitably 2 to 6 carbon atoms, still more suitably 2 to 4 carbon atoms. These groups may optionally be substituted with hydroxy, chloro, bromo, iodo, cyano, nitro, OR 19 、OC(O)R 20 、C(O)R 21 、C(O)OR 22 NR 23 R 24 、C(O)NR 25 R 26 SR 27 、C(O)SR 27 、C(S)NR 25 R 26, or aryl substituted, wherein R 19 to R 27 Each independently represents hydrogen, aryl or alkyl, and / or is interrupted by oxygen or sulfur atoms, or by silane or dialkylsiloxane groups. Examples of such groups can be independently selected from alkenyl groups, including vinyl, allyl, isopropenyl, pentenyl, hexenyl, heptenyl, cyclopropenyl, cyclobutenyl, cyclopentenyl, cyclohexenyl, 1-propenyl, 2-butenyl, 2-methyl-2-butenyl, isoprenyl, farnesyl, geranyl, geranylgeranyl, etc. As used herein, the term "alkenylene" refers to a divalent group alkenyl as defined above. For example, when represented as alkenylene, an alkenyl group such as vinyl (which is represented as -CH=CH2) becomes vinylene -CH=CH-. Other alkenylene groups should be understood accordingly.

[0039] As used herein, the term "alkynyl" refers to a hydrocarbon group having triple bonds, suitably up to 4 triple bonds, which is a linear, branched, cyclic or polycyclic moiety or a combination thereof and has 2 to 18 carbon atoms, suitably 2 to 10 carbon atoms, more suitably 2 to 8 carbon atoms, still more suitably 2 to 6 carbon atoms, still more suitably 2 to 4 carbon atoms. These groups may optionally be substituted with hydroxy, chloro, bromo, iodo, cyano, nitro, OR 19 、OC(O)R 20 、C(O)R 21 、C(O)OR 22 NR 23 R 24 、C(O)NR 25 R 26 SR 27 、C(O)SR 27 、C(S)NR 25 R 26 , or aryl substituted, wherein R 19 to R 27 Each independently represents hydrogen, aryl or lower alkyl, and / or is interrupted by oxygen or sulfur atoms, or by silane or dialkylsiloxane groups. Examples of such groups can be independently selected from alkynyl groups, including ethynyl, propynyl, propargyl, butynyl, pentynyl, hexynyl, etc. As used herein, the term "alkynylene" refers to the divalent group alkynyl as defined above. For example, when represented as alkynylene, an alkynyl group such as ethynyl (which would be represented as -C≡CH) becomes ethynylene-C≡C-. Other alkynylene groups should be understood accordingly.

[0040] As used herein, the term "aryl" refers to an organic radical derived from an aromatic hydrocarbon by removing one hydrogen and comprising any monocyclic, bicyclic or polycyclic carbocyclic ring with up to 7 members in each ring, wherein at least one ring is aromatic. These groups may be optionally substituted with hydroxy, chloro, bromo, iodo, cyano, nitro, OR 19 、OC(O)R 20 、C(O)R 21 、C(O)OR 22 NR 23 R 24 、C(O)NR 25 R 26 SR 27 、C(O)SR 27 、C(S)NR 25 R 26 , or aryl substituted, wherein R 19 to R 27 Each independently represents hydrogen, aryl or lower alkyl, and / or is interrupted by oxygen or sulfur atoms, or by silane or dialkylsilyl groups. Examples of such groups may be independently selected from phenyl, p-tolyl, 4-methoxyphenyl, 4-(tert-butyloxy)phenyl, 3-methyl-4-methoxyphenyl, 4-fluorophenyl, 4-chlorophenyl, 3-nitrophenyl, 3-aminophenyl, 3-acetylaminophenyl, 4-acetylaminophenyl, 2-methyl-3-acetylaminophenyl, 2-methyl-3-aminophenyl, 3-methyl-4-aminophenyl, 2-amino-3-methylphenyl, 2,4-dimethyl-3-aminophenyl, 4-hydroxyphenyl, 3-methyl-4-hydroxyphenyl, 1-naphthyl, 2-naphthyl, 3-amino-1-naphthyl, 2-methyl-3-amino-1-naphthyl, 6-amino-2-naphthyl, 4,6-dimethoxy-2-naphthyl, tetrahydronaphthyl, indanyl, biphenyl, phenanthrenyl, anthracenyl or acenaphthenyl, etc. As used herein, the term "arylene" relates to a divalent radical aryl as defined above. For example, an aryl group such as phenyl (which would be represented as -Ph) when represented as an arylene group becomes phenylene-Ph-. Other arylene groups should be construed accordingly.

[0041] For the avoidance of doubt, references to alkyl, alkenyl, alkynyl, aryl or aralkyl in composite groups herein should be construed accordingly, for example references to alkyl in aminoalkyl or alkane in alkoxy should be construed as references to the aforementioned alkane or alkyl groups.

[0042] As used herein, unless expressly provided otherwise, all numbers such as those expressing values, ranges, amounts or percentages may be read as if prefixed by the word "about", even if the term does not explicitly appear. Likewise, any numerical range recited herein is intended to include all subranges therein. The singular encompasses the plural, and vice versa. For example, while reference is made herein to, for example, "a" polyesterimide polymer, "a" cross-linking agent, "an" imide, "the" residue of "an", etc., the term "polymer" as used herein refers to both oligomers and homopolymers and copolymers, and the prefix "poly / multi" refers to two or more. Including, for example and similar terms all mean including, for example, but not limited to.

[0043] The formation of the polyesterimide polymer (polyesterification) can be carried out in the presence of a catalyst. Suitable catalysts include: tetra-n-butyl titanate; tetraisopropyl titanate; tetraethylhexyl titanate; zinc acetate; dibutyltin oxide; butylstannoic acid; or a combination thereof.

[0044] Polyesterimide polymers can be formed as follows: In a first-stage reaction (imide preparation reaction), a cyclic anhydride component reacts with an amine or isocyanate component at a suitable temperature to produce a cyclic imide having reactive functionality. This reaction may be carried out in the presence of a promoter / catalyst. However, in some cases, catalysis may not be required. In a second-stage reaction (polyesterification reaction), other components, such as diols, polyols, and diacids or ester derivatives (depending on the functionality of the imide), may be added to the product of the first-stage reaction along with a suitable catalyst (if necessary).

[0045] The amount of diols and polyols present in the polyesterification reaction can be sufficient to provide excess hydroxyl functionality during the formation process, which can initially provide the dominant hydroxyl functionality in the polyesterimide polymer. The polyesterification reaction is suitably carried out at a temperature sufficient to allow removal of water or alcohol (particularly methanol) by-products as the polymer forms. The progress of the polyesterification reaction can be monitored by suitable methods, including: the amount of distillate released, the acid number of the polymer (measured in units of mg KOH / g) or the viscosity of the polymer (melt viscosity or solution viscosity). The polyesterimide polymer can have terminal functional groups, including hydroxyl, acid or ester groups, which are derived from monoalcohols.

[0046] Polyesterimide polymers can be formed by a first reaction of a cyclic anhydride component with an amine or isocyanate component in the presence of some or all of the diol component at a suitable temperature to produce a cyclic imide having reactive functionality. An accelerator and / or catalyst may be added to this first-stage reaction. However, in some cases, catalysis may not be necessary.

[0047] In the second stage, the other components of the polyesterimide, including any remaining diols, polyols and diacid or ester derivatives, can be added along with a suitable catalyst. The amount of diol and polyol added can be sufficient to provide excess hydroxyl functionality, which provides the dominant hydroxyl functionality in the polyesterimide polymer.

[0048] Suitably, the second stage reaction is carried out at a temperature sufficient to allow removal of water or alcohol (particularly methanol) by-products as the polymer is formed. The progress of the second stage reaction can be monitored by suitable methods, including the amount of distillate released, the acid number and / or hydroxyl number (measured in mg KOH / g units) of the polymer, or the polymer viscosity (melt viscosity or solution viscosity). The polyesterimide polymer has terminal functional groups, including hydroxyl, acid or ester groups, which are derived from monoalcohols.

[0049] Polyesterimide polymers can be formed by a first reaction (polyesterification) of diols, polyols and diacids or ester derivatives, which can be carried out in the presence of a promoter and / or catalyst. However, in some cases, a catalyst may not be required. In the second stage reaction, a cyclic anhydride component and an amine component (or possible isocyanate component) are added, and the subsequent reaction is carried out at a suitable temperature to produce a cyclic imide with reactive functionality, which further reacts with the polyester oligomer formed in the first stage reaction (polyesterification). Suitable catalysts and / or reaction promoters can be added as needed, but in some cases, a catalyst may not be required.

[0050] The amount of diols and polyols present in the polyesterification reaction can be sufficient to provide an excess of hydroxyl functionality, which can provide the dominant hydroxyl functionality in the polymer. The polyesterification reaction is suitably carried out at a temperature sufficient to allow the removal of water or alcohol (particularly methanol) by-products as the polymer is formed. The progress of the polyesterification reaction in stage 1 and the imide formation and reaction in stage 2 can be monitored by suitable methods, including: the amount of distillate released, the acid number of the polymer (measured in mgKOH / gm units) or the polymer viscosity (melt viscosity or solution viscosity). The polyesterimide polymer can have terminal functional groups, including hydroxyl, acid or ester groups, which are derived from monoalcohols.

[0051] The polyesterimide polymer has an acid value of ≥ 10 mg KOH / g. The polyesterimide polymer can be formed by contacting a polyesterimide (e.g., formed as described above) with an acidifying component. The acidifying component can be selected from an acid, a diacid, a polyanhydride thereof, or a mixture thereof. Examples of suitable acidifying components include, but are not limited to, the following: isophthalic acid; terephthalic acid; 1,4-cyclohexanedicarboxylic acid; succinic acid; adipic acid; azelaic acid; sebacic acid; fumaric acid; 2,6-naphthalene dicarboxylic acid; phthalic acid; trimellitic anhydride, succinic anhydride; maleic anhydride; tetrahydrophthalic anhydride, or a combination thereof.

[0052] The polyesterimide polymer may comprise at least 1 wt % of imide, based on the total weight of the components, suitably contained in its backbone. The polyesterimide polymer may comprise at least 2 wt %, suitably at least 3 wt % of imide, based on the total weight of the components, suitably contained in its backbone.

[0053] The polyesterimide polymer may contain less than 50 wt%, suitably less than 30 wt%, of imide, based on the total weight of the components, suitably contained in its backbone. The polyesterimide polymer may contain less than 25 wt%, suitably less than 20 wt%, of imide, based on the total weight of the components, suitably contained in its backbone.

[0054] The polyesterimide polymer may contain 2-20 wt%, such as 4-18 wt%, of imide, based on the total weight of the components, suitably contained in its backbone.

[0055] When referring to the percentage of imide present in a polyesterimide polymer based on the total weight of the components, it means the following: The polyesterimide polymer comprises imide units consisting of the chemical structural unit [-N(C=O)2-], the atomic weight of which is 70 gmol -1 To obtain some quantification of the weight of a polymer component that could theoretically form an imide, a calculation can be used to determine the weight percent of imide based on the weight of the component. This calculation is shown below:

[0056] [mol of imide used (mol of imide-forming component, e.g., cyclic anhydride) x 70 x 100] / [total weight of polymer components]

[0057] The proportion of imides formed in the polyesterimide polymers of the present invention can also be characterized by referring to the molar ratio of the components. Specifically, we can refer to the ratio of the moles of imide-forming groups to the moles of ester-forming groups (moles of carboxylic acid or their equivalents, such as the amount of methyl ester). This can therefore be calculated as the % imide equivalent weight according to the following calculation:

[0058] [mol of imide-forming groups (or cyclic anhydrides) x 100] / [(mol of imide-forming groups) + (mol of ester-forming groups)]

[0059] The polyesterimide polymer may have a percentage imide equivalent value of at least 5%, suitably at least 10%, for example at least 15%.

[0060] The polyesterimide polymer may have a percentage imide equivalent value of less than 60%, suitably less than 50%, for example less than 45%.

[0061] The polyesterimide polymer may have an imide equivalent weight percentage of 5-50%, suitably 13-45%, for example 18-41%.

[0062] The polyesterimide polymer may have any suitable acid value (or acid number (AN)). The polyesterimide polymer may have an acid number of 10-150 mg KOH / g, suitably 15-100 mg KOH / g, for example 18-75 mg KOH / g, or 20-50 mg KOH / g or 22-40 mg KOH / g.

[0063] The polyesterimide polymer has an acid value of at least 10 mg KOH / g. The polyesterimide polymer may have an acid value of at least 15 mg KOH / g, for example at least 18 mg KOH / g, or at least 20 or 22 mg KOH / g. The polyesterimide polymer may have an acid value of up to 150 mg KOH / g, suitably up to 120 mg KOH / g, for example up to 100 mg KOH / g, or up to 90 or 80 mg KOH / g. The polyesterimide polymer may have an acid value of 15-150 mg KOH / g, for example 18-120 mg KOH / g, or 20-120 mg KOH / g, or 22-120 mg KOH / g. The acid value of the polyesterimide polymer may be 10-100 mg KOH / g, suitably 15-100 mg KOH / g, for example 18-100 mg KOH / g, or 20-100 mg KOH / g or 22-100 mg KOH / g. The acid value of the polyesterimide polymer may be 10-90 mg KOH / g, suitably 15-90 mg KOH / g, for example 18-90 mg KOH / g, or 20-90 mg KOH / g or 22-90 mg KOH / g.

[0064] Suitably, the acid number is expressed on a solids basis.

[0065] The acid value is determined by titration with 0.1N methanolic potassium hydroxide solution. A polymer sample (0.1-3 g, depending on the acid value) is accurately weighed (on a balance with a weighing accuracy of milligrams) into an Erlenmeyer flask and then dissolved in 25 ml of a solvent mixture containing dichloromethane and ethanol (3 / 1 w / w) and a few drops of a 0.1% solution of bromothymol blue indicator; gentle heating and appropriate stirring are used. The solution is then cooled to room temperature (20-30°C) and titrated with potassium hydroxide solution. The resulting acid value is expressed in mg KOH / g units and is calculated using the following equation:

[0066] Acid value = (titer KOH solution (ml) X molar concentration of KOH solution X 56.1) / solid sample weight (g)

[0067] The polyesterimide polymer may have any suitable hydroxyl value (OHV).The polyesterimide polymer may have a hydroxyl value of 10-300 mg KOH / g, or 50-200 mg KOH / g, or 100-180 mg KOH / g.

[0068] Suitably, the hydroxyl value (OHV) is expressed on a solids basis.

[0069] The total hydroxyl value (OHV) can be measured by any suitable method. Methods for measuring OHV will be well known to those skilled in the art. Suitably, the hydroxyl value is the number of mg of KOH equivalent to the hydroxyl groups in 1 g of material. In an exemplary method, suitably, a sample (typically 0.1-3 g) is accurately weighed into an Erlenmeyer flask and dissolved in 20 ml of tetrahydrofuran using gentle heating and appropriate stirring. 10 ml of a 0.1 M solution of 4-(dimethylamino)pyridine in tetrahydrofuran (catalyst solution) and 5 ml of a 9 vol% solution of acetic anhydride in tetrahydrofuran (i.e., 90 ml of acetic anhydride in 910 ml of tetrahydrofuran; acetylation solution) are then added to the mixture. After 5 minutes, 10 ml of an 80 vol% solution of tetrahydrofuran (i.e., 4 parts by volume of tetrahydrofuran to 1 part of distilled water; hydrolysis solution) is added. After 15 minutes, 10 ml of tetrahydrofuran is added, and the solution is titrated with 0.5 M ethanolic potassium hydroxide (KOH). A blank sample was also run in which the solid polyester sample was omitted. The resulting hydroxyl value is expressed in mg KOH / g units and is calculated using the following equation:

[0070] Hydroxyl value = (V2–V1) x KOH solution molar concentration (M) x 56.1

[0071] Solid sample weight (g)

[0072] Where V1 is the titer of the KOH solution of the polyester sample (ml) and V2 is the titer of the KOH solution of the blank sample (ml). All values ​​of total hydroxyl value (OHV) reported here are measured in this way.

[0073] The polyesterimide polymer may have any suitable number average molecular weight (Mn).The Mn of the polyesterimide polymer may be 500-200,000 Daltons (Da=g / mol), suitably 1,000-100,000 Da, such as 2,000-75,000 Da, or even 2,500-50,000 Da.

[0074] The Mn of the polyesterimide polymer can be at least 500Da, suitably at least 1000Da, for example at least 2000Da, or even 2500Da. The Mn of the polyesterimide polymer can be as high as 200,000Da, suitably as high as 100,000Da, for example as high as 75,000Da, or even as high as 50,000Da. The Mn of the polyesterimide polymer can be 500-200,000Da, suitably 1000-200,000Da, for example 2000-200,000Da, or even 2500-200,000Da. The Mn of the polyesterimide polymer can be 500-100,000Da, suitably 1000-100,000Da, for example 2000-100,000Da, or even 2500-100,000Da. The polyesterimide polymer may have an Mn of 500-75,000 Da, suitably 1,000-75,000 Da, for example 2,000-75,000 Da, or even 2,500-75,000 Da.The polyesterimide polymer may have an Mn of 500-50,000 Da, suitably 1,000-50,000 Da, for example 2,000-50,000 Da, or even 2,500-50,000 Da.

[0075] The number average molecular weight can be measured by any suitable method. The techniques for measuring number average molecular weight will be well known to those skilled in the art. Suitably, Mn can be determined by gel permeation chromatography using polystyrene standards according to ASTM D 6579-11 ("Standard Practice for Molecular Weight Averages and Molecular Weight Distribution of Hydrocarbon, Rosin and Terpene Resins by Size Exclusion Chromatography". UV detector; 254 nm, solvent: unstabilized THF, retention time marker: toluene, sample concentration: 2 mg / ml).

[0076] The polyesterimide polymer may have any suitable weight average molecular weight (Mw). The Mw of the polyesterimide polymer may be 500-200,000 Daltons (Da=g / mol), suitably 1,000-100,000 Da, such as 2,000-75,000 Da, or 2,500-50,000 Da, or 4,000-40,000.

[0077] The Mw of the polyesterimide polymer may be at least 500 Da, suitably at least 1000 Da, for example at least 2000 Da, or at least 2500 Da or at least 4000 Da. The Mw of the polyesterimide polymer may be as high as 200,000 Da, suitably as high as 100,000 Da, for example as high as 75,000 Da, or as high as 50,000 Da or as high as 40,000 Da. The Mw of the polyesterimide polymer may be 500-200,000 Da, suitably 1,000-200,000 Da, for example 2,000-200,000 Da, or 2,500-200,000 Da or 4,000-200,000 Da. The Mw of the polyesterimide polymer may be 500-100,000 Da, suitably 1,000-100,000 Da, for example 2,000-100,000 Da, or 2,500-100,000 Da or 4,000-100,000 Da. The Mw of the polyesterimide polymer may be 500-75,000 Da, suitably 1,000-75,000 Da, for example 2,000-75,000 Da, or 2,500-75,000 Da or 4,000-75,000 Da. The Mw of the polyesterimide polymer may be 500-50,000 Da, suitably 1,000-50,000 Da, for example 2,000-50,000 Da, or 2,500-50,000 Da or 4,000-50,000 Da.

[0078] Those skilled in the art will understand that techniques for measuring number average molecular weight can also be used to measure weight average molecular weight.

[0079] The polyesterimide polymer according to any aspect of the present invention may be in solid form at room temperature and pressure.

[0080] The polyesterimide polymer may have any suitable glass transition temperature (Tg).The polyesterimide polymer may have a Tg of 20-150°C, suitably 25-100°C, for example 30-80°C or 40-70°C.

[0081] The polyesterimide polymer may have a Tg of at least 20°C, suitably at least 25°C, such as at least 30°C, or even at least 40°C. The polyesterimide polymer may have a Tg of up to 150°C, suitably up to 100°C, such as up to 80°C, or even up to 70°C. The polyesterimide polymer may have a Tg of 20-150°C, suitably 25-150°C, such as 30-150°C, or even 40-150°C. The polyesterimide polymer may have a Tg of 20-100°C, suitably 25-100°C, such as 30-100°C, or even 40-100°C. The polyesterimide polymer may have a Tg of 20-80°C, suitably 25-80°C, such as 30-80°C, or even 40-80°C. The polyesterimide polymer may have a Tg of 20-70°C, suitably 25-70°C, for example 30-70°C, or even 40-70°C.

[0082] The Tg of polyesterimide polymer can be measured by any suitable method. The method of measuring Tg will be well known to those skilled in the art. Suitably, Tg is measured according to ASTM D6604-00 (2013) ("Standard Practice for Glass Transition Temperatures of Hydrocarbon Resins by Differential Scanning Calorimetry". Heat flux differential scanning calorimeter (DSC), sample pan: aluminum, reference: blank, calibration: indium and mercury, sample weight: 10 mg, heating rate: 20 ° C / min).

[0083] Suitably, the polyesterimide polymer may have a Tg of 40-70°C.

[0084] The polyesterimide polymer may have any suitable viscosity at 180° C. The polyesterimide polymer may have a viscosity at 180° C. of 2-500 poise, suitably 10-500 poise, for example 50-500 poise, or 80-500 poise, or 80-450 poise.

[0085] Melt viscosity is measured using a cone-plate viscometer using a heated plate with a cone that can be selected together with an appropriate rotational speed to measure viscosity within the desired range. In this work, the cone-plate viscometer used was a Brookfield CAP2000+ machine, which is capable of measuring viscosity at temperatures between 100 and 250°C. The selected measurement temperature was kept constant throughout the measurement time, and the details of the temperature used are recorded in each example. The cone used was a No. 6 spindle, and the rotational speed was selected to ensure that the measurement range fell well within the total measurement range.

[0086] The coating composition can be a powder composition or a liquid composition. When the composition is a liquid composition, the composition can include a solvent and / or a carrier. The powder can be present in the liquid carrier in the form of a dispersion or slurry.

[0087] The coating composition may comprise a single solvent / carrier or a mixture of solvents / carriers. The solvent / carrier may comprise water, an organic solvent / carrier, a mixture of water and an organic solvent / carrier, or a mixture of organic solvents / carriers.

[0088] The organic solvent / carrier is suitably sufficiently volatile to evaporate substantially completely from the coating composition during the curing process.By way of non-limiting example, the curing process may be heating at 130-300°C for 1-15 minutes.

[0089] Suitable organic solvents / carriers include, but are not limited to, the following: aliphatic hydrocarbons such as mineral spirits and high flash point naphtha; aromatic hydrocarbons such as benzene; toluene; xylene; solvent naphtha 100, 150, 200; those available from Exxon-Mobil Chemical Company under the SOLVESSO trademark; alcohols such as ethanol; n-propanol; isopropanol; methoxypropanol; and n-butanol; ketones such as acetone; cyclohexanone; methyl isobutyl ketone; methyl ethyl ketone; esters such as ethyl acetate; butyl acetate; n-hexyl acetate; dibasic esters; butoxylates; glycols such as butanediol; glycol ethers such as 1-methoxypropanol; ethylene glycol monomethyl ether; ethylene glycol monobutyl ether; benzyl alcohol mixed with xylene; benzyl acetate; ethyl lactate; n-butyl pyrrolidone, and combinations thereof. The solvent / carrier, when present, may suitably be used in the coating composition in an amount of about 10-90 wt%, such as about 20-80 wt%, or even about 30-70 wt%, based on the total solids weight of the coating composition.

[0090] The coating composition may be a thermosetting powder coating composition.

[0091] The coating composition of the present invention comprises a crosslinking agent. The crosslinking agent can be any suitable crosslinking agent that is used to crosslink the acid functionality on the polyesterimide polymer.

[0092] Suitable cross-linking agents are well known to those skilled in the art. Suitable cross-linking agents include, but are not limited to, the following: phenolic resins (or phenolic resins); aminoplast resins (or triazine formaldehyde resins); amino resins; epoxy resins; epoxy-mimic resins, such as those based on bisphenol and other bisphenol A (BPA) substitutes; isocyanate resins, isocyanurate resins, such as triglycidyl isocyanurate; hydroxy (alkyl) amide resins, such as β-hydroxy (alkyl) amide resins; hydroxy (alkyl) urea resins; carbodiimide resins; oxazolines; polyamines; polyamides and combinations thereof.

[0093] The crosslinking agent may be selected from hydroxy(alkyl)amide resins, such as β-hydroxy(alkyl)amide resins; hydroxy(alkyl)urea resins; carbodiimide resins, such as polycarbodiimide resins; oxazoline; isocyanurate resins, such as triglycidyl isocyanurate; epoxy resins such as those based on bisphenol and other bisphenol A (BPA) substitutes; or combinations thereof. Suitably, the crosslinking agent may be selected from hydroxy(alkyl)amide resins, such as β-hydroxy(alkyl)amide resins and / or hydroxy(alkyl)urea resins and / or carbodiimide resins. Suitably, the crosslinking agent may be selected from hydroxy(alkyl)amide resins, such as β-hydroxy(alkyl)amide resins and / or hydroxy(alkyl)urea resins.

[0094] Suitably, the cross-linking agent comprises a hydroxyalkylamide material and / or a hydroxyalkylurea material and / or a carbodiimide resin. Suitably, the cross-linking agent comprises a hydroxyalkylamide material and / or a hydroxyalkylurea material.

[0095] The cross-linking agent may comprise a phenolic resin. Non-limiting examples of phenolic resins are those formed by the reaction of phenols with formaldehyde. Non-limiting examples of phenols that can be used to form phenolic resins are phenol, butylphenol, xylenol and cresol. The general preparation of phenolic resins is described in "The Chemistry and Application of Phenolic Resins or Phenoplasts", Volume V, Part I, edited by Dr Oldring; John Wiley and Sons / Cita Technology Limited, London, 1997. Suitably, the phenolic resin is of the resol type. By "resol type" we mean a resin formed in the presence of an alkaline (base) catalyst and optionally an excess of formaldehyde. Suitable examples of commercially available phenolic resins include, but are not limited to PR 285, VPR 1785, PR 517 and BR 612 and in the trade name For example, the resin sold under BAKELITE 6582LB.

[0096] The crosslinking agent may comprise an isocyanate resin. Suitable isocyanates include, but are not limited to, polyfunctional isocyanates. Suitable examples of polyfunctional polyisocyanates include, but are not limited to, the following: aliphatic diisocyanates such as hexamethylene diisocyanate and isophorone diisocyanate; and aromatic diisocyanates such as toluene diisocyanate and 4,4'-diphenylmethane diisocyanate. The polyisocyanate may be blocked or unblocked. Other examples of suitable polyisocyanates include, but are not limited to, the following: isocyanurate trimers; allophanates; uretdiones of diisocyanates; polycarbodiimides, and combinations thereof. Suitable examples of commercially available polyisocyanates include, but are not limited to, DESMODUR VP LS2078 / 2 and DESMODUR N 3390, which are sold by Bayer Corporation, and TOLONATE HDT 90, which is sold by Rhodia Inc.

[0097] Suitable amino resins include melamine formaldehyde type materials of the hexa(methoxymethyl)melamine (HMMM) type such as KOMELOL 90GE (available from Melamin), MAPRENAL MF 900 (available from Ineos Melamines) or RESIMENE 745 or RESIMENE 747 (available from Ineos Melamines) or CYMEL 303 or CYMELMM 100 (available from Cytec). Other melamine formaldehyde type materials such as butylated methylol melamine type resins such as CYMEL 1156 or CYMEL 1158 (commercially available from Cytec) or mixed ether type methyl melamine resins such as CYMEL 1116, CYMEL 1130, CYMEL 1133 or CYMEL 1168 (commercially available from Cytec), particularly suitable amino resins would include partially methylolated or partially methylated melamine type resins such as CYMEL 370, CYMEL 325 or CYMEL 327 (commercially available from Cytec).

[0098] Other types of suitable amino resins include benzoguanamine, formaldehyde type materials such as CYMEL 1123 (available from Cytec), Itamin BG 143 (available from Galstaff Multiresine) or Uramex BF 892 (available from DSM). Further examples of suitable amino resins include glycoluril based materials such as CYMEL 1170 and CYMEL 1172 (available from Cytec).

[0099] Suitable hydroxy-functional silicone resins include DOW CORNING 255 or DOW CORNING 217 (commercially available from Dow Corning).

[0100] The cross-linking agent may be an acid-reactive cross-linking agent, which is a cross-linking agent that can be used to cross-link polymers by reacting with acid functional groups on the polymer, which are suitably located between carboxyl functional groups on the polymer.

[0101] The crosslinking agent may be selected from hydroxy (alkyl) amide resins, such as β-hydroxy (alkyl) amide resins; hydroxy (alkyl) urea resins; carbodiimide resins; oxazoline; glyoxal; isocyanurate resins, such as triglycidyl isocyanurate; epoxy resins, such as those based on bisphenol and other bisphenol A (BPA) substitutes; or combinations thereof. Suitably, the crosslinking agent may be selected from hydroxy (alkyl) amide resins, such as β-hydroxy (alkyl) amide resins; hydroxy (alkyl) urea resins; or combinations thereof.

[0102] The crosslinking agent may contain nitrogen. The crosslinking agent may be in the form of an amine or amide material. The crosslinking agent may be a hydroxyl-functional crosslinking agent. The crosslinking agent may comprise a hydroxyl-substituted amine or amide material.

[0103] The crosslinking agent may comprise a hydroxyalkylamide crosslinking agent. Suitably, the crosslinking agent comprises a β-hydroxyalkylamide crosslinking agent. Suitably, when the coating composition is a thermosetting powder coating composition, the crosslinking agent comprises a solid crosslinking agent, such as a β-hydroxyalkylamide crosslinking agent.

[0104] The hydroxyalkylamide crosslinking agent may comprise a terminal chemical group represented by Formula I.

[0105]

[0106] where R 1 represents an electron-withdrawing group, such as (=O);

[0107] and Y 1 and Y 2 Each independently represents a C1-C3 alkylene group.

[0108] The terminal chemical group of Formula I may be attached to another chemical structure (not shown). Additionally or alternatively, the chemical group of Formula I may be pendant from a support substrate such as, for example, a silica support substrate.

[0109] The hydroxyalkylamide crosslinking agent may comprise multiple terminal chemical groups of Formula I. For example, the hydroxyalkylamide crosslinking agent may comprise 2, 3, or 4 terminal chemical groups of Formula I.

[0110] The hydroxyalkylamide crosslinker may comprise a moiety according to Formula II:

[0111]

[0112] wherein R 1 and R 2 Each independently represents an electron withdrawing group such as (=O); Y of formula II 1 , Y 2 , Y 3 and Y 4 each independently represents a C1-C3 alkylene group; and X is a C2-C6 alkylene group.

[0113] Suitably, each R of formula II 1 and R 2 represents a (=O) group.

[0114] Suitably, each of Y1, Y2, Y3 and Y4 in relation to formula II represents an ethylene group.

[0115] Suitably, X represents butylene.

[0116] Thus, hydroxyalkylamide crosslinkers include materials of formula III:

[0117]

[0118] The coating composition of the present invention may include commercially available hydroxyalkylamide crosslinkers such as PRIMID XL-552 (available from EMS Chemie); PRIMID QM-1260 (available from EMS Chemie); PRIMID SF-4510 (available from EMS Chemie) and N,N,N',N'-tetrakis(2-hydroxypropyl)adipamide.

[0119] The cross-linking agent may be in the form of a urea material.The cross-linking agent may comprise a hydroxy-substituted urea material.

[0120] Suitably, the cross-linking agent may comprise a hydroxy-functional alkyl polyurea material.

[0121] The cross-linking agent may comprise a terminal chemical group represented by Formula IV.

[0122]

[0123] where Y 5 and Y 6 Each independently represents hydrogen, an alkyl group or a hydroxy-functional alkyl group having 2 or more carbon atoms, and Y 5 and Y 6 At least one is a hydroxy-functional alkyl group having 2 or more carbon atoms.

[0124] Y 5and Y 6 The group may not include an ether linkage.

[0125] The terminal chemical group of formula IV may be attached to other chemical structures (not shown). Additionally or alternatively, the chemical group of formula IV may be suspended from a support substrate, such as a silica support substrate.

[0126] The crosslinking agent may comprise a plurality of terminal chemical groups of Formula IV. For example, the crosslinking agent may comprise 2-6 terminal chemical groups of Formula IV, such as 2, 3 or 4 terminal chemical groups of Formula IV.

[0127] The crosslinker material may comprise a moiety according to Formula V:

[0128]

[0129] wherein R1 of Formula V comprises the residue of an isocyanurate, a biuret, an allophanate, a glycoluril, a benzoguanamine, a polyetheramine, and / or a polymeric moiety with an Mn of 500 or greater; each R1 of Formula V is independently hydrogen, an alkyl group, or a hydroxy-functional alkyl group having 2 or more carbon atoms, and at least one R1 of Formula V is a hydroxy-functional alkyl group having 2 or more carbon atoms; and n is 2-6.

[0130] Suitably, the R1 group referred to in formula V may not include an ether linkage.

[0131] The cross-linking agent may comprise a moiety according to formula VI:

[0132]

[0133] Wherein R2 of formula VI comprises substituted or unsubstituted C1-C 36 an alkyl group, an aryl group, or the residue of an isocyanurate, a biuret, an allophanate, a glycoluril, a benzoguanamine, a polyetheramine, and / or a polymeric moiety with an Mn of 500 or greater; each R1 of Formula VI is independently hydrogen, an alkyl group having 1 or more carbon atoms, or a hydroxy-functional alkyl group having 2 or more carbon atoms, and at least one R1 of Formula VI is a hydroxy-functional alkyl group having 2 or more carbon atoms; and n is 2-6.

[0134] Suitably, when referring to Formula VI, R2 is substituted or unsubstituted C1-C 36 When alkyl, the acid functional polyester material contains COOH functionality which reacts with the polyurea to form ester linkages.

[0135] Suitably, the R1 group in relation to formula VI may not include an ether linkage.

[0136] It will be understood that when R2 of Formula VI is a substituted or unsubstituted alkyl group, there may be two R2 groups of Formula VI attached to the N, and the two R2 groups of Formula VI may be the same or different. For example, if the hydroxyl-functional alkyl polyurea is formed by reacting dimethyl carbonate with dibutylamine and diisopropanolamine, there will be two R2 groups of Formula VI, each of which is C4.

[0137] Relate to R and R of formula VI and can comprise following residue: isocyanurate, biuret, allophanate, glycoluril, benzoguanamine, polyetheramine and / or Mn is 500 or larger polymer part.Isocyanurate will be understood to mean the compound with three isocyanate groups, is usually in ring form, and is sometimes referred to as trimer.This can comprise the compound with one or more isocyanurate moieties.Isocyanurate can be purchased from Covestro and Vencore XChemical. Suitable commercially available isocyanurates include those sold under the DESMODUR trademark, such as DESMODURN 3300A, DESMODUR N3800, DESMODUR N3790, DESMODUR N3400, DESMODUR N3600, DESMODURN 3900 and DESMODUR RC (available from Covestro), those sold under the VESTANANT trademark, such as VESTANATT 1890 / 100 (available from Evonik) and those sold under the EASAQUA trademark, such as EASAQUA WT 2102, EASAQUA X D401, EASAQUA M501, EASAQUA X D803, EASAQUA M502 and EASAQUA X L600 (available from Vencore X Chemical). Unsaturated isocyanate monomers include, but are not limited to, 2-acryloyloxyethyl isocyanate (AOI), 2-methacryloyloxyethyl isocyanate (MOI), α,α-dimethyl-m-isopropenylbenzyl isocyanate (TMI), and a 1:1 adduct of 2-hydroxyethyl acrylate (HEA) and IPDI. A particularly suitable hydroxyl-functional alkyl polyurea formed from isocyanurate is shown in Formula VII:

[0138]

[0139] wherein R1 with respect to formula VII is as described above; and each R3 independently comprises an alkyl group, an aryl group, an alkylaryl group, an arylalkyl group, an alicyclic group and / or a polyetheralkyl group.

[0140] A particularly suitable hydroxyl-functional alkyl polyurea formed from diisocyanurate is shown below in Formula VIII:

[0141]

[0142] wherein R1 and R3 with respect to formula VIII are as described above.

[0143] Biuret is understood to mean a compound formed by the condensation of two urea molecules and is sometimes referred to as carbamoyl urea. Biuret is commercially available from Vencore X Chemical and Covestro as, for example, DESMODUR N-75, DESMODUR N-100 and DESMODUR N-3200, HDB75B, HDB75M, HDB75MX, HDB-LV. A particularly suitable hydroxy-functional alkyl polyurea formed from biuret is shown in the following formula IX:

[0144]

[0145] wherein R1 with respect to Formula IX is as described above; each R5 independently comprises an alkyl group, an aryl group, an alkylaryl group, an arylalkyl group, an alicyclic group and / or a polyetheralkyl group; and R6 comprises H or an alkyl group.

[0146] Uretdiones are dimers of diisocyanates, examples of which include DESMODUR N-3400 polyisocyanate, a trimer, and a uretdione mixture of HDI:

[0147]

[0148] wherein each R5 independently comprises an alkyl group, an aryl group, an alkylaryl group, an arylalkyl group, an alicyclic group, and / or a polyether alkyl group.

[0149] Allophanate will be understood to refer to compounds made from carbamate and isocyanate. A method for making allophanate is described in Surface Coating, Vol. 1, Raw material and their usage, Landon New York, Chapman and Hall, p. 106. The reaction is generally represented by Scheme 1 below:

[0150]

[0151] wherein R5 and R6 with respect to Scheme 1 are each as described above; and R7 independently comprises the residue of a primary alcohol.

[0152] Glycoluril will be understood to mean a compound consisting of two cyclic urea groups joined along the same double carbon chain, suitable examples of which include the following:

[0153]

[0154] Glycoluril is widely commercially available, for example, from Sigma-Aldrich. Benzoguanamine is also known as 6-phenyl-1,3,5-triazine-2,4-diamine and is commercially available from The Chemical Company, Jamestown, RI.

[0155] Polyetheramines will be understood to mean compounds having one or more amine groups attached to a polyether backbone, such as those characterized by propylene oxide, ethylene oxide, or mixed propylene oxide and ethylene oxide repeating units in their respective structures, such as one of the Jeffamine series of products. Examples of such polyetheramines include aminated propoxylated pentaerythritol, such as JEFFAMINE XTJ-616, and those of formula (X) to (VI).

[0156] According to formula (IV), the polyetheramine may include:

[0157]

[0158] Wherein y=0-39, x+z=1-68.

[0159] Suitable amine-containing compounds represented by Formula X include, but are not limited to, amine-terminated polyethylene glycols such as those commercially available from Huntsman Corporation in its JEFFAMINE ED series, e.g., JEFFAMINE HK-511, JEFFAMINE ED-600, JEFFAMINE ED-900, and JEFFAMINE ED-2003, and amine-terminated polypropylene glycols such as in its JEFFAMINE D series, e.g., JEFFAMINE D-230, JEFFAMINE D-400, JEFFAMINE D-2000, and JEFFAMINE D-4000.

[0160] According to Formula XI, the polyetheramine may include:

[0161]

[0162] wherein each p is independently 2 or 3.

[0163] Suitable amine-containing compounds represented by formula XI include, but are not limited to, diamines based on amine-terminated polyethylene glycols, such as the JEFFAMINE EDR series from Huntsman Corporation, eg, JEFFAMINE EDR-148 and JEFFAMINE EDR-176.

[0164] According to Formula XII, the polyetheramine may include:

[0165]

[0166] Wherein R8 is H or C2H5, m=0 or 1, a+b+c=5-85.

[0167] Suitable amine-containing compounds of formula (VI) include, but are not limited to, amine-terminated trimethylolpropane propoxylate or glycerol, such as Huntsman Corporation's JEFFAMINE T series, such as JEFFAMINE T-403, JEFFAMINE T-3000, and JEFFAMINE T-5000.

[0168] Particularly suitable are diamines and triamines, for example 4,7,10-trioxa-1,13-tridecanediamine, JEFFAMINE D400, JEFFAMINE D4000, JEFFAMINE D2000, JEFFAMINE T403.

[0169] As used herein in the context of R or R2 of Formula V-IX, "polymer moiety" refers to any polymer or oligomer that has been attached to 2-6 hydroxyl-functional alkyl polyurea groups. The polymer may, for example, be a polyester polyurethane, a polyether polyurethane, or a polyamide polyurethane. The moiety may itself contain functionality, such as acid functionality, hydroxy functionality and / or amine functionality. The Mn of the polymer moiety (which may be an oligomer as described above) is 500 or greater, such as 1000 or greater, 2500 or greater, 4000 or greater, or 5000 or greater. As used herein, Mn refers to the number average molecular weight and represents the theoretical value as measured by gel permeation chromatography using a Waters 2695 separation module, a Waters 410 differential refractometer (RI detector) and polystyrene standards. The Mn values ​​reported in accordance with the present invention are determined using this method. Tetrahydrofuran (THF) is used as the molecular weight at 1 ml min -1 The eluent was at a flow rate of 1.5 ng / min, and two PL Gel mixed C columns were used for separation.

[0170] In all cases, R and R2 in relation to formula V-IX may be substituted or unsubstituted. As mentioned above, R2 in relation to formula V-IX may also contain substituted or unsubstituted C1-C 36 Alkyl and / or aryl groups. For example, the alkyl group may have 2 to 10 carbon atoms, for example 6 carbon atoms. The alkyl group may be derived from an isocyanate such as a diisocyanate. Suitable examples include isophorone diisocyanate and hexamethylene isocyanate. The aryl group may be derived from an isocyanate containing an aromatic ring, suitable examples of which include methylene diphenyl diisocyanate, toluene diisocyanate, and tetramethylxylylene diisocyanate.

[0171] Certain hydroxyl-functional alkyl polyureas of the present invention and / or used according to the present invention can be made by reacting an isocyanate-containing compound with an amino alcohol. Any isocyanate-containing compound having at least two isocyanate groups can be used, such as any of those described above. It will be understood that the "R" or "R2" group referring to Formulas V-IX will reflect the selected isocyanate-containing compound, if used.

[0172] Similarly, any amino alcohol having 2 or more carbon atoms may be used, and the "R" group in relation to Formulas V-IX will reflect the amino alcohol selected. The amino alcohol may have 1, 2, or more hydroxyl functional groups. One or more amino alcohols may be used, which will result in different R groups in relation to Formulas V-IX being present on the polyurea. R in relation to Formulas V-IX may also be hydrogen or an alkyl group. Suitable amino alcohols include monoethanolamine, diethanolamine, and diisopropanolamine.

[0173] Hydroxyl functional alkyl polyureas can be prepared by reacting an amino alcohol with an isocyanate-containing compound in an organic polar solvent such as an alcohol or water. The equivalent ratio of amine to isocyanate can be 2-1:1-2, for example 1:1.

[0174] Hydroxy-functional alkyl polyureas can also be prepared by an alternative method. For example, amino alcohols can be reacted with carbonates to form hydroxyalkyl carbamates, and the hydroxyalkyl carbamates can be further reacted with amines to form hydroxy-functional alkyl polyureas.

[0175] The number average molecular weight (Mn) of the hydroxy-functional alkyl polyurea (even when the polyurea is in monomeric or prepolymer form, but not when R or R2 as referred to in Formulas V-IX is a polymeric moiety) can be 100 or greater, such as 350 or greater or 1000 or greater, and / or can be 6000 or less, such as 3000 or less, or 2000 or less. When R or R2 as referred to in Formulas V-IX is a polymeric moiety, the Mn of the hydroxy-functional alkyl polyurea can be 500 or greater, such as 1000 or greater, 5000 or greater, or 10,000 or greater.

[0176] The present inventors have surprisingly and advantageously discovered that hydroxyalkyl urea functional materials generally cure at lower temperatures than, for example, hydroxyalkyl amide materials, such as beta-hydroxyalkyl amide materials.

[0177] The crosslinking agent may be in the form of a carbodiimide resin. The crosslinking agent may comprise a polycarbodiimide. Suitably, the crosslinking agent may comprise a polycarbodiimide having the following structural units (XIII) or (XIV), including mixtures thereof:

[0178]

[0179] wherein e is an integer from 2 to 20; f and g are each at least 1, and f+g is an integer up to 20; and E is a group selected from the following:

[0180]

[0181] Wherein R of the structural unit (XIII) or (XIV) 2 Containing a cyclic group and R related to (XV) and (XVI) 3 is a straight chain hydrocarbon group containing at least 4 carbon atoms, and R 4 is hydrogen or an alkyl group.

[0182] Polycarbodiimides can be prepared by reacting polyisocyanates containing organic groups in the presence of suitable catalysts to form polycarbodiimides having terminal NCO functionality, wherein the active hydrogen-containing compound is added before, during or after the formation of the polycarbodiimide.

[0183] The polyisocyanate may be aliphatic, including cycloaliphatic, or aromatic, or a mixture of the two. Aliphatic polyisocyanates, including cycloaliphatic ones, and alkylaryl polyisocyanates are particularly suitable. The polyisocyanate may contain 2 to 4, for example 2, isocyanate groups per molecule. Examples of suitable higher polyisocyanates are 1,2,4-benzene triisocyanate and polymethylene polyphenyl isocyanate. Examples of suitable aromatic diisocyanates are 4,4′-diphenylmethane diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, and toluene diisocyanate. Examples of suitable aliphatic diisocyanates are linear aliphatic diisocyanates such as 1,4-tetramethylene diisocyanate and 1,6-hexamethylene diisocyanate and alkylaryl polyisocyanates such as m-tetramethylxylene diisocyanate. Cycloaliphatic diisocyanates may also be used. Examples include 1,4-cyclohexyl diisocyanate, isophorone diisocyanate, α,α-xylylene diisocyanate, and 4,4-methylene-bis(cyclohexyl isocyanate). Substituted polyisocyanates containing organic groups may also be used, where the substituents are nitro, chloro, alkoxy, and other groups that are non-reactive with hydroxyl groups or active hydrogen, provided that the substituents are not positioned to render the isocyanate groups non-reactive.

[0184] Active hydrogen-containing compounds used to prepare polycarbodiimides are suitable chain extenders or spacers that link polyisocyanates together to form NCO-adducts or link NCO-functional polycarbodiimides together. Any suitable organic compound containing active hydrogen can be used. The term "active hydrogen atom" refers to a hydrogen that exhibits activity according to the Zerewitinoff test due to its position in the molecule. Thus, active hydrogen includes hydrogen atoms attached to oxygen or nitrogen, and therefore useful compounds will include those having at least two of these groups (in any combination):

[0185] -OH, and -NH2

[0186] The moiety attached to each group may be aliphatic, including alicyclic, aromatic, or mixed types, with aliphatics being particularly suitable.

[0187] The active hydrogen-containing material may contain 2 to 4, particularly suitably 2, active hydrogens per molecule.

[0188] Examples of such compounds include amines, including polyamines, amino alcohols, thiol-terminated derivatives, and alcohols, including polyhydroxy materials (polyols), which are particularly suitable due to their ease in reacting with polyisocyanates. Polyols also typically do not exhibit side reactions, resulting in higher carbamate product yields and no by-products, and the products are hydrolytically stable. Similarly, there are a wide variety of available materials for polyols, which can be selected to produce a wide range of desired properties. In addition, polyols have a desirable reaction rate with polyisocyanates. Both saturated and unsaturated active hydrogen-containing compounds can be used, but saturated materials are particularly suitable due to their excellent coating properties.

[0189] Polyhydroxy materials or polyols can be low or high molecular weight materials and typically have an average hydroxyl number of 2000 or less, such as 2000 to 10, as measured by ASTM designation E-222-67, Method B. The term "polyol" is intended to include materials having an average of 2 or more hydroxyl groups per molecule.

[0190] Polyols include low molecular weight diols, triols and higher molecular weight polyols, low molecular weight amide-containing polyols and higher polymer polyols such as polyester polyols, polyether polyols, polycarbonate polyols and hydroxyl-containing (meth)acrylic polymers. The polymers typically have a hydroxyl number of 10-180. Similarly, the polymers typically have a number average molecular weight of 96-10,000 Da.

[0191] Low molecular weight diols, triols, and higher alcohols useful in the present invention are known in the art. They have a hydroxyl number of 200 or higher, typically 200-2000. Such materials include aliphatic polyols, particularly alkylene polyols containing 4-18 carbon atoms. Examples include 1,4-butanediol and 1,6-hexanediol. Also useful are polyols containing ether linkages, such as diethylene glycol and tetraethylene glycol.

[0192] To form polycarbodiimides, polyisocyanates with or without active hydrogen-containing compounds may be condensed with elimination of carbon dioxide to form polycarbodiimides, i.e., polyisocyanates containing [N=C=N] n Polymers of units wherein n in relation to [N=C=N] is 2-20, for example 2-10.

[0193] The condensation reaction is usually carried out by heating a solution of a polyisocyanate in the presence of a suitable catalyst. Examples of catalysts include 1-ethyl-3-phospholine, 1-ethyl-3-methyl-3-phospholine-1-oxide, 1-ethyl-3-methyl-3-phospholine-1-sulfide, 1-ethyl-3-methyl-phosphine, 1-ethyl-3-methyl-phosphine-1-oxide, 3-methyl-1-phenyl-3-phospholine-1-oxide and bicyclic terpene alkyl or alkyl aryl phosphine oxide or camphene phenyl phosphine oxide.

[0194] The specific amount of catalyst used will depend largely on the reactivity of the catalyst itself and the polyisocyanate to be used. Concentrations of 0.05 to 5 parts catalyst per 100 parts adduct are generally suitable.

[0195] The resulting polycarbodiimide has terminal NCO groups which can then react with active hydrogen-containing hydrophilic compounds.

[0196] The hydrophilic compound may be a polyether alcohol or polyether amine or a mixture thereof having a polyether backbone, typically based on ethylene oxide or mixed ethylene oxide and propylene, and having a number average molecular weight greater than 500, such as at least 1000. Typical alcohols and amines have the following structural formula:

[0197] (XVII)R-(-O-CH2-CH2-) a -(-O-CH2-CH(CH3)-) b -DN(R 1 )-H

[0198] or

[0199] (XVIII)R-(-O-CH2-CH2-) a-(-O-CH2-CH(CH3)-) b -D-OH

[0200] wherein R in relation to formula (XVII) and (XVIII) is C1-C4 alkyl; a in relation to formula (XVII) and (XVIII) is 5-50 and b in relation to formula (XVII) and (XVIII) is 0-35, and when b in relation to formula (XVII) and (XVIII) is present, the a:b molar ratio in relation to formula (XVII) and (XVIII) is at least 1:1; R in relation to formula (XVIII) is 1 is hydrogen or a hydrocarbon group, and D in relation to formulae (XVII) and (XVIII) is a divalent linking group or a chemical bond.

[0201] The reaction of the polyether alcohol or amine with the NCO-containing carbodiimide can be carried out in a stoichiometric ratio of equivalents of amine to NCO equivalents or a slight excess of alcohol or amine and at a temperature of typically 80-110° C. until the IR spectrum of the reaction mixture indicates essentially no remaining NCO functionality.

[0202] Depending on when an active hydrogen chain extender or spacer is used in the reaction, the polycarbodiimide has a structure such that each carbodiimide unit or polycarbodiimide unit is linked to a unit selected from carbamate, thiourethane urea, thiourea and a hydrophilic unit is present at one or the terminal positions of the polycarbodiimide via a carbamate or urea linkage.

[0203] Typically, the polycarbodiimide has a weight average molecular weight of 2600-12000, such as 3000-10000, and an imide equivalent weight (number average molecular weight / number of carbodiimide groups) of at least 600, such as 600-2000.

[0204] When the active hydrogen chain extender is added before or during the formation of the polycarbodiimide, i.e., used to chain extend the polyisocyanate to form an NCO-adduct, and when the polyisocyanate and the active hydrogen-containing compound are difunctional, the polycarbodiimide can be represented by the following structural formula:

[0205]

[0206] wherein e in formula (XIX) is an integer from 2 to 20, for example, from 2 to 10; and E in formula (XIX) is selected from the following groups:

[0207]

[0208] Wherein R of formula (XIX) 2 is a cyclic group such as an alicyclic group or an alkaryl group, which may contain 6 to 20 carbon atoms, such as those of the following structure:

[0209]

[0210] R of formula (XX) and (XXI) 3 is a straight chain hydrocarbon group, which optionally includes heteroatoms and contains at least 4 carbon atoms, such as a polyethylene group having a number average molecular weight of 96-10,000. 4 is hydrogen or a hydrocarbon group such as an alkyl group containing 1 to 4 carbon atoms. In formula (XIX), Y is a group of the following structure:

[0211] (XXII)R-(-O-CH2-CH2-) a -(-O-CH2-CH(CH3)-) b -DN(R 1 )-C(O)-NH-

[0212] or

[0213] (XXIII)R-(-O-CH2-CH2-) a -(-O-CH2-CH(CH3)-) b -DOC(O)-NH-

[0214] wherein R in relation to formula (XXII) and (XXIII) is C1-C4 alkyl; a in relation to formula (XXII) and (XXIII) is 5-50 and b in relation to formula (XXII) and (XXIII) is 0-35, and when b in relation to formula (XXII) and (XXIII) is present, the a:b molar ratio in relation to formula (XXII) and (XXIII) is at least 1:1; R in relation to formula (XXII) 1 is hydrogen or a hydrocarbon group and D in relation to formulae (XXII) and (XXIII) is a divalent linking group or a chemical bond.

[0215] When the active hydrogen chain extender is added after polycarbodiimide formation, ie, to chain extend the NCO-functional polycarbodiimide, when the NCO-functional polycarbodiimide and the active hydrogen-containing compound are difunctional, the polycarbodiimide can be represented by the following structural formula.

[0216]

[0217] wherein f and g with respect to formula (XXIV) are each at least 1, and f+g with respect to formula (XXIV) is an integer up to 20, for example up to 10; and E with respect to formula (XXIV) is a group selected from the following:

[0218]

[0219] Wherein R of formula (XXIV), (XXV) and (XXVI) 2 , R 3 , R 4 and Y have the meanings described above for (XIX).

[0220] An organic solvent may optionally be present in the synthesis of the polycarbodiimide. Polar water-miscible solvents such as N-methylpyrrolidone may be used in an amount of about 5 to 25 weight percent based on the weight of the reaction mixture.

[0221] The coating composition may comprise any suitable weight ratio of polyesterimide (a):crosslinker (b). The coating composition may have a weight ratio of (a):(b) of 50:1 to 1:10, suitably 50:1 to 1:1, such as 30:1 to 10:1, or even 25:1 to 15:1.

[0222] The powder coating composition of the present invention can have any suitable average particle size. The average particle size of the coating composition can be 10-1000 microns (μm), suitably 10-500 μm, for example 10-250 μm, or even 10-100 μm. Particles with these sizes can be produced by any suitable method. Suitable methods will be well known to those skilled in the art. Examples of suitable methods include, but are not limited to, cold grinding and screening methods.

[0223] The average particle size is the D50 value, which is the median value, dividing the distribution with half above this size and half below this size. This value is volume-based and is sometimes called Dv50.

[0224] The coating composition of the present invention may comprise any suitable amount of polyesterimide polymer (a). The coating composition may comprise 10-99.9 wt %, suitably 25-99 wt %, such as 50-99 wt % or even 60-99 wt % of polyesterimide polymer (a), based on the total solid weight of the coating composition.

[0225] The coating composition of the present invention may contain any suitable amount of crosslinking agent (b). The coating composition may contain 1-20 wt%, suitably 1.5-15 wt%, such as 2-10 wt%, or even 2.5-7.5 wt% of crosslinking agent (b), based on the total solid weight of the coating composition.

[0226] The coating composition may comprise at least 1 wt %, suitably at least 1.5 wt %, such as at least 2 wt %, or even at least 2.5 wt % of a crosslinker (b), based on the total solid weight of the coating composition. The coating composition may comprise up to 20 wt %, suitably up to 15 wt %, such as up to 10 wt %, or even up to 7.5 wt % of a crosslinker (b), based on the total solid weight of the coating composition. The coating composition may comprise 1-20 wt %, suitably 1.5-20 wt %, such as 2-20 wt %, or even 2.5-20 wt % of a crosslinker (b), based on the total solid weight of the coating composition. The coating composition may comprise 1-15 wt %, suitably 1.5-15 wt %, such as 2-15 wt %, or even 2.5-15 wt % of a crosslinker (b), based on the total solid weight of the coating composition. The coating composition may comprise 1-10 wt %, suitably 1.5-10 wt %, such as 2-10 wt %, or even 2.5-10 wt % of the crosslinker (b), based on the total solid weight of the coating composition. The coating composition may comprise 1-7.5 wt %, suitably 1.5-7.5 wt %, such as 2-7.5 wt %, or even 2.5-7.5 wt % of the crosslinker (b), based on the total solid weight of the coating composition.

[0227] The composition of the present invention may include a titanate material. The titanate material may include an organic titanate material, such as a titanate substituted with (e.g., 1, 2, 3, or 4) organic groups. In this context, each organic group may include a substituted or unsubstituted, linear, cyclic, or branched C1-C 12 Alkyl, alkenyl or aryl.

[0228] The titanate material may comprise a titanate substituted with (eg, 1, 2, 3, or 4) organic groups, each independently selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, pentyl, hexyl, cyclohexyl.

[0229] The titanate material may be selected from tetra-n-butyl titanate; tetraisopropyl titanate; tetraethylhexyl titanate; zinc acetate; dibutyltin oxide; butylstannoic acid; or a combination thereof.

[0230] The titanate material is present in the coating composition in an amount of at least 0.1 wt % (based on the dry weight of the coating ingredients), alternatively at least 0.5 wt %, alternatively at least 1 wt %.

[0231] The titanate material may be present in the coating composition in an amount less than 25 wt % (based on the dry weight of the coating ingredients), more suitably less than 15 wt % or less than 10 wt % or less than 5 wt %.

[0232] The titanate material may be present in the coating composition in an amount of 0.1 to 10 wt% (based on the dry weight of the coating ingredients) and more suitably 0.5 to 6 wt% or 1 to 5 wt%.

[0233] Where the coating composition of the present invention is a solid material such as a powder coating composition, the titanate material may be added to a polyesterimide material having an acid value ≥ 10 in a solvent and then the resulting composition is dried, thereby capturing the titanate material in the solid coating composition.

[0234] The coating composition of the present invention may further comprise a pigment and / or a filler. The coating composition may comprise a single pigment or filler or a mixture of pigments and / or fillers. Suitable pigments include, but are not limited to, the following: titanium dioxide; ultramarine blue; phthalocyanines such as phthalocyanine blue and phthalocyanine green; anthraquinone; quinacridone; thioindigo; carbon black; graphite fibrils; iron oxides such as black iron oxide; chromium oxide green; iron yellow; quinacridone red; or combinations thereof. Suitable fillers include, but are not limited to, the following: barium sulfate; silica such as precipitated silica, fumed silica, and clay; or combinations thereof.

[0235] Suitably, the coating composition may comprise titanium dioxide, barium sulfate or a combination thereof. Suitably, the coating composition may comprise titanium dioxide and barium sulfate.

[0236] Pigments and / or fillers, when present, may be used in the coating composition in any suitable amount. Pigments and / or fillers, when present, may be used in the coating composition in an amount of 0-50 wt%, suitably 0-40 wt%, such as 0-30 wt%, or even 0-25 wt%, based on the total solids weight of the coating composition.

[0237] The coating composition may further comprise a curing catalyst. The coating composition may comprise any curing agent suitable for catalyzing the reaction between the acid-functional polyester material and the crosslinking agent, such as a hydroxyalkylamide crosslinking agent. Suitable curing catalysts are well known to those skilled in the art. Examples of suitable curing catalysts include, but are not limited to, the following: organotin compounds, such as tin (II) salts of carboxylic acids, such as tin (II) acetate, tin (II) octoate, tin (II) ethylhexanoate, and tin (II) laurate, tin (IV) compounds such as dibutyltin oxide, dibutyltin dichloride, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin maleate, and dioctyltin diacetate; tertiary amines such as diazabicyclo [2.2.2] octane and 1,5-diazabicyclo [4.3.0] non-5-ene; and combinations thereof.

[0238] The coating compositions of the present invention may optionally include additional additives or combinations of additives. The coating compositions may optionally include any suitable additive or combination of additives. Suitable additives are well known to those skilled in the art. Examples of suitable additives include, but are not limited to, the following: lubricants; diluents; plasticizers; surfactants; stabilizers; flow control agents; thixotropic agents; and combinations thereof.

[0239] Suitable lubricants are well known to those skilled in the art. Suitable examples of lubricants include, but are not limited to, the following: carnauba wax and polyethylene type lubricants. When present, the lubricant may be present in the coating composition in an amount of at least 0.01 wt %, based on the total solids weight of the coating composition.

[0240] Surfactants can optionally be added to the coating composition to aid flow and wetting of the substrate. Suitable surfactants are well known to those skilled in the art. Those skilled in the art will appreciate that when the coating composition is used in food and / or beverage container applications, the surfactant, when present, is selected to be compatible with such applications. Suitable surfactants include, but are not limited to, the following: alkyl sulfates (e.g., sodium lauryl sulfate); ether sulfates; phosphate esters; sulfonate esters; and their various alkali, ammonium, and amine salts; fatty alcohol ethoxylates; alkylphenol ethoxylates (e.g., nonylphenol polyethers); salts and / or combinations thereof. When present, the surfactant can be used in the coating composition in an amount of 0.01-10 wt %, based on the total solids weight of the coating composition.

[0241] Suitable flow control agents are well known to those skilled in the art. Suitable flow control agents include, but are not limited to, the following: acrylate polymers, such as polylauryl acrylate, polybutyl acrylate, poly(2-ethylhexyl) acrylate, poly(ethyl-2-ethylhexyl) acrylate, polylauryl methacrylate, and polyisodecyl methacrylate; fluorinated polymers, such as esters of polyethylene glycol or polypropylene glycol and fluorinated fatty acids, such as polyethylene glycol having a molecular weight exceeding 2500 Da and esters of perfluorooctanoic acid; polysiloxanes, such as polysiloxanes having a molecular weight exceeding 1000 Da, such as poly(dimethylsiloxane) and poly(methylphenylsiloxane); and combinations thereof. When present, the flow control agent may be used in the coating composition in an amount of 0.01-10 wt %, suitably 0.1-5 wt %, such as 0.5-4 wt % or even 1-3 wt %, based on the total solid weight of the coating composition.

[0242] Those skilled in the art will appreciate that flow control agents, when present, must be suitable for use with the powder composition.

[0243] The coating composition according to the present invention is substantially free of bisphenol A (BPA) and its derivatives. The coating composition may be substantially free of, or completely free of, bisphenol A (BPA) and its derivatives. Derivatives of bisphenol A include, for example, bisphenol A diglycidyl ether (BADGE). The coating composition according to the present invention is also substantially free of bisphenol F (BBF) and its derivatives. The coating composition may be substantially free of, or completely free of, bisphenol F (BPF) and its derivatives. Derivatives of bisphenol F include, for example, bisphenol F diglycidyl ether (BPFG). These compounds or their derivatives may not be intentionally added to the composition but may be present in trace amounts due to unavoidable contamination from the environment. By "substantially free," we mean that the coating composition contains less than 1000 parts per million (ppm) of any of the above compounds or their derivatives. By "substantially free," we mean that the coating composition contains less than 100 ppm of any of the above compounds or their derivatives. By "completely free," we mean that the coating composition contains less than 20 parts per billion (ppb) of any of the above compounds or their derivatives.

[0244] The coating compositions of the present invention may be substantially free of or completely free of dialkyltin compounds, including oxides or other derivatives thereof. Examples of dialkyltin compounds include, but are not limited to, the following: dibutyltin dilaurate (DBTDL); dioctyltin dilaurate; dimethyltin oxide; diethyltin oxide; dipropyltin oxide; dibutyltin oxide (DBTO); dioctyltin oxide (DOTO), or combinations thereof. By "substantially free," we mean that the coating composition contains less than 1000 parts per million (ppm) of any of the above compounds or their derivatives. By "substantially free," we mean that the coating composition contains less than 100 ppm of any of the above compounds or their derivatives. By "completely free," we mean that the coating composition contains less than 20 parts per billion (ppb) of any compound or its derivative.

[0245] The coating compositions of the present invention may be substantially free, essentially free, or completely free of bromine. By "substantially free," we mean that the coating composition contains less than 1000 parts per million (ppm) of bromine. By "substantially free," we mean that the coating composition contains less than 100 ppm of bromine. By "completely free," we mean that the coating composition contains less than 20 parts per billion (ppb) of bromine.

[0246] The coating compositions of the present invention may be substantially free, essentially free, or completely free of solvent. By "substantially free," we mean that the coating composition contains less than 1000 parts per million (ppm) of solvent. By "substantially free," we mean that the coating composition contains less than 100 ppm of solvent. By "completely free," we mean that the coating composition contains less than 20 parts per billion (ppb) of solvent.

[0247] The coating composition of the present invention can be prepared by any suitable method. For example, the coating composition can be prepared by first dry-mixing the acid-functional polyester material, cross-linking agent (if present), pigment and / or filler, curing agent and additives in a mixer. The mixer can be run for any suitable time. Suitably, the mixer can be run for a sufficient time to obtain a uniform dry blend of the materials added thereto. The uniform dry blend can then be melt-mixed in an extruder, such as a twin-screw co-rotating extruder, which operates in the temperature range of 80-140° C., suitably 100-125° C. The extrudate of the coating composition can be cooled and typically ground to the above-mentioned average particle size.

[0248] The coating compositions of the present invention are curable coating compositions. As used herein, "curable coating composition" and like terms refer to a coating composition that is initially in a powdered state and ultimately in a state in which the coating composition has been converted into a substantially continuous, agglomerated state.

[0249] The coating composition of the present invention may be cured by any suitable method. The coating composition may be cured by thermal curing or by chemical curing, suitably by thermal curing. The coating composition, when thermally cured, may be cured at any suitable temperature. The coating composition, when thermally cured, may be cured at a temperature of 50-350°C, suitably 100-320°C, for example 150-300°C or even 200-300°C or 230-280°C, for example 250-280°C or 260-280°C. Advantageously, it has been found that curing at higher temperatures, for example at least 240, 250, 260 or 270°C, results in further improved properties.

[0250] The coating compositions according to the present invention can be applied to any suitable substrate. Examples of suitable substrates include, but are not limited to, food and / or beverage cans or components used to make such cans. Examples of cans include, but are not limited to, two-piece cans, three-piece cans, and the like. The coating compositions of the present invention can also be applied to containers for aerosol applications, such as, but not limited to, deodorant and hair spray containers. Containers for aerosol applications can be single-piece aerosol cans and / or tubes, such as aluminum single-piece aerosol cans and / or tubes.

[0251] According to another aspect of the present invention, there is provided a method for preparing an acid-functional polyesterimide polymer having an acid value ≥10 mg KOH / g; the method comprising the steps of:

[0252] a. forming a polyester imide polymer;

[0253] b. optionally contacting the polyesterimide polymer with a blocking agent such as a monoacid functionalized blocking agent;

[0254] c. contacting the polyesterimide polymer with an acidifying component which may be selected from a diacid or polyacid, or an ester or anhydride thereof;

[0255] d. Optionally contacting the polyesterimide with a titanate material and an optional support.

[0256] A blocking agent may be used to react with the hydroxyl group. The blocking agent may comprise p-tert-butylbenzoic acid.

[0257] The titanate material is as defined above, and may be in a carrier such as a solvent.

[0258] According to another aspect of the present invention, there is provided a metal substrate having at least a portion thereof coated with a coating, wherein the coating is derived from a coating composition comprising:

[0259] a. A polyester imide (PEI) polymer having an acid value ≥10 mg KOH / g; and

[0260] b. a crosslinking agent which can be used to crosslink the acid functionality on the polyesterimide polymer;

[0261] The coating composition is substantially free of bisphenol A (BPA), bisphenol F (BPF), bisphenol A diglycidyl ether (BADGE) and bisphenol F diglycidyl ether (BFDGE).

[0262] According to another aspect of the present invention, there is provided a food and / or beverage container, at least a portion of which is coated with a coating, wherein the coating is derived from a coating composition comprising:

[0263] a. A polyester imide (PEI) polymer having an acid value ≥10 mg KOH / g; and

[0264] b. a crosslinking agent which can be used to crosslink the acid functionality on the polyesterimide polymer;

[0265] The coating composition is substantially free of bisphenol A (BPA), bisphenol F (BPF), bisphenol A diglycidyl ether (BADGE) and bisphenol F diglycidyl ether (BFDGE).

[0266] According to another aspect of the present invention, there is provided a monolithic aerosol can and / or tube, at least a portion of which is coated with a coating, wherein the coating is derived from a coating composition comprising:

[0267] a. A polyester imide (PEI) polymer having an acid value ≥10 mg KOH / g; and

[0268] b. a crosslinking agent which can be used to crosslink the acid functionality on the polyesterimide polymer;

[0269] The coating composition is substantially free of bisphenol A (BPA), bisphenol F (BPF), bisphenol A diglycidyl ether (BADGE) and bisphenol F diglycidyl ether (BFDGE).

[0270] According to another aspect of the present invention, there is provided a food and / or beverage packaging container containing food or beverage, wherein the packaging container is coated with a coating on at least a portion thereof, wherein the coating is derived from a coating composition comprising:

[0271] a. A polyester imide (PEI) polymer having an acid value ≥10 mg KOH / g; and

[0272] b. a crosslinking agent which can be used to crosslink the acid functionality on the polyesterimide polymer;

[0273] The coating composition is substantially free of bisphenol A (BPA), bisphenol F (BPF), bisphenol A diglycidyl ether (BADGE) and bisphenol F diglycidyl ether (BFDGE).

[0274] According to another aspect of the present invention, there is provided a monolithic aerosol can and / or tube comprising a cosmetic formulation, wherein the can and / or tube is coated on at least a portion thereof with a coating, wherein the coating is derived from a coating composition comprising:

[0275] a. A polyester imide (PEI) polymer having an acid value ≥10 mg KOH / g; and

[0276] b. a crosslinking agent which can be used to crosslink the acid functionality on the polyesterimide polymer;

[0277] The coating composition is substantially free of bisphenol A (BPA), bisphenol F (BPF), bisphenol A diglycidyl ether (BADGE) and bisphenol F diglycidyl ether (BFDGE).

[0278] The substrate may be formed from any suitable material. Suitable materials will be known to those skilled in the art. Suitable examples include, but are not limited to, the following: steel; tinplate; tinplate pretreated with a protective material such as chromium, titanium, titanate, or aluminum; tin-free steel (TFS); galvanized steel such as electroplated steel; aluminum; aluminum alloys; and combinations thereof.

[0279] The coating compositions of the present invention can be applied to a substrate by any suitable method. Methods for applying the coating compositions to a substrate are well known to those skilled in the art. Suitable application methods include, but are not limited to, spraying; roller coating; dipping; brushing; electrocoating; and electrostatic spraying, such as supercorona discharge.

[0280] Suitably, the powder coating composition according to the present invention may be applied to a substrate by supercorona discharge.

[0281] When the substrate is conductive, the powder coating composition is typically applied electrostatically. Electrostatic spraying typically involves extracting the powder coating composition from a fluidized bed and driving it through a corona field. The particles of the coating composition become charged as they pass through the corona field and are attracted to and deposited on a grounded conductive substrate. As the charged particles begin to accumulate, the substrate becomes insulating, thereby limiting further particle deposition. This insulation phenomenon typically limits the film formation of the deposited coating composition to a maximum of 250-300 μm (micrometers), and in some cases 75-150 μm.

[0282] The coating composition according to the present invention may be applied to a substrate to any suitable dry film thickness. The coating composition according to the first aspect of the present invention may be applied to a substrate to a dry film thickness of 0.1 μm (micrometer) to 300 μm, suitably 3 μm to 250 μm, for example 5 μm to 150 μm, or even 5 μm to 75 μm or 5 μm to 50 μm or 5 μm to 40 μm, or 10 μm to 30 μm, 13 μm to 23 μm or 15 μm to 21 μm.

[0283] The coating composition of the present invention can be applied to a substrate as a single layer or as part of a multi-layer system. The coating composition of the present invention can be applied to a substrate as a single layer. The coating composition of the present invention can be applied to a substrate as the first coating layer of a multi-coat system. Suitably, the coating composition of the present invention can be applied to a substrate as a primer or undercoat. The second, third, fourth, etc. coating layers can comprise any suitable paint, such as those containing, for example, epoxy resins; polyester resins; polyurethane resins; polysiloxane resins; hydrocarbon resins, or combinations thereof. The coating composition of the present invention can be applied on top of another paint layer as part of a multi-layer system. For example, the coating composition of the present invention can be applied on top of a primer. The coating composition of the present invention can form an intermediate layer or a topcoat. The coating composition of the present invention can be applied to a substrate one or more times. Any or all of the layers can be substantially free, essentially free, or completely free of BPA, BPF, and their derivatives.

[0284] All features contained therein may be combined with any of the above aspects, and in any combination.

[0285] For a better understanding of the invention and to show how its embodiments can be implemented, reference is now made to the following experimental data by way of example. Example

[0286] Intermediate polyesterimide polymer A

[0287] An intermediate polyesterimide polymer having predominantly hydroxy functionality was prepared from the following ingredients and according to the following procedure:

[0288] A total of 12.77 kg of ethylene glycol, 8.87 kg of 4,4'-methylenebis(phenyl isocyanate), and 13.63 kg of trimellitic anhydride were added to a suitable reaction vessel equipped with an agitator, a temperature probe, a glycol recovery unit (a packed column and a distillation head connected to a water-cooled condenser), and a nitrogen sparge. The reaction vessel contents were carefully heated to 150°C and then held at 150-155°C for 4 hours while removing 1 kg of distillate.

[0289] The reaction vessel contents were then maintained at 150-155°C and 16.30 kg of tris(2-hydroxyethyl)isocyanurate, 15.22 kg of terephthalic acid, and 6.62 kg of isophthalic acid were added to the reaction mixture. The reaction vessel contents were heated to 235°C and continuous water distillation was initiated at 169°C. The reaction vessel contents were maintained at 232-238°C, with water removed as distillate, until the acid number of the reaction mixture reached 7.0 mgKOH / gm. The melt viscosity at 180°C was 66.9 poise.

[0290] The contents of the reaction vessel were then cooled to 200°C, poured out, cooled to room temperature and pulverized into pieces. The reaction product had an acid number of 6.3 mg KOH / gm, a melt viscosity of 71 poise at 180°C and a weight average molecular weight of 4637 measured relative to polystyrene standards.

[0291] A series of polyesterimide polymers according to the present invention were prepared according to the following formulations and procedures. All amounts are given in parts by weight (pbw).

[0292] Polymer B

[0293] Polyesterimide polymer B was prepared from the following ingredients and according to the following procedure:

[0294] A total of 1000 g of Polymer A and 40 g of trimellitic anhydride were added to a suitable reaction vessel equipped with an agitator, a temperature probe, a glycol recovery unit (a packed column and a distillation head connected to a water-cooled condenser), and a nitrogen sparge. The reaction vessel contents were heated to 150° C. to melt the contents, and then heated to 185° C. The reaction vessel contents were maintained at 182-188° C., and a small amount of water was removed as distillate until the reaction mixture had an acid value of 39.7 mg KOH / gm.

[0295] The contents of the reaction vessel were cooled to 170° C., then poured out, cooled to room temperature and pulverized into pieces. The reaction product had an acid number of 34.5 mg KOH / gm, a melt viscosity of 266 poise at 180° C., a Tg of 60.7° C., and a weight average molecular weight of 5207 measured relative to polystyrene standards.

[0296] Polymer C

[0297] Polyesterimide polymer C was prepared from the following ingredients and according to the following procedure: A total of 1000 g of polymer A and 100 g of p-tert-butylbenzoic acid were added to a suitable reaction vessel equipped with an agitator, a temperature probe, a glycol recovery unit (a packed column and a distillation head connected to a water-cooled condenser), and a nitrogen sparge. The reaction vessel contents were heated to 160° C. to melt the contents, and then heated to 240° C. with continuous removal of water as distillate. The reaction vessel contents were maintained at 240-245° C. with water removed as distillate until the reaction mixture had an acid value of 13.7 mg KOH / gm.

[0298] The reaction vessel contents were cooled to 180° C. and 60.0 g of trimellitic anhydride was added to the reaction mixture. The reaction vessel contents were maintained at 178-182° C. and a small amount of water was removed as distillate until the reaction mixture had an acid number of 49.7 mg KOH / gm and a melt viscosity of 244 poise at 180° C.

[0299] The contents of the reaction vessel were then cooled to 170° C., poured out, cooled to room temperature and pulverized into pieces. The reaction product had an acid number of 39.2 mg KOH / gm, a melt viscosity of 360 poise at 180° C., a Tg of 66° C., and a weight average molecular weight of 10,376 measured relative to polystyrene standards.

[0300] Polymer D

[0301] Polyesterimide polymers were prepared from the following ingredients and according to the following procedure:

[0302] A total of 1000 g of Polymer A and 100.0 g of p-tert-butylbenzoic acid were added to a suitable reaction vessel equipped with an agitator, a temperature probe, a glycol recovery unit (a packed column and a distillation head connected to a water-cooled condenser), and a nitrogen sparge. The reaction vessel contents were heated to 160° C. to melt the contents, then heated to 210° C. with continuous removal of water as distillate. The reaction vessel contents were maintained at 208-212° C. with water removed as distillate until the reaction mixture had an acid value of 16.0 mg KOH / gm.

[0303] The contents of the reaction vessel were cooled to 200° C. and 70.0 g of adipic acid was added to the reaction mixture. The contents of the reaction vessel were maintained at 198-202° C. and vacuum was used as needed to facilitate distillation to remove water as distillate. The reaction was continued until the acid number of the reaction mixture was 33.3 mg KOH / gm and the melt viscosity at 180° C. was 84 poise.

[0304] The contents of the reaction vessel were then cooled to 180° C., poured out, cooled to room temperature and pulverized into pieces. The reaction product had an acid number of 32.1 mg KOH / gm, a melt viscosity of 92 poise at 180° C., a Tg of 51.3° C., and a weight average molecular weight of 8351 measured relative to polystyrene standards.

[0305] Polymer E

[0306] Polyesterimide polymer F was prepared from the following ingredients and according to the following procedure:

[0307] A total of 1000 g of Polymer A and 60.0 g of p-tert-butylbenzoic acid were added to a suitable reaction vessel equipped with an agitator, a temperature probe, a glycol recovery unit (a packed column and a distillation head connected to a water-cooled condenser), and a nitrogen sparge. The contents of the reaction vessel were heated to 160° C. to melt the contents, then heated to 210° C. with continuous removal of water as distillate. The contents of the reaction vessel were maintained at 208-212° C. with water removed as distillate until the reaction mixture had an acid value of 12.0 mg KOH / gm.

[0308] The contents of the reaction vessel were cooled to 200° C. and 95.0 g of adipic acid was added to the reaction mixture. The contents of the reaction vessel were maintained at 208-212° C. and vacuum was used as needed to facilitate distillation to remove water as distillate. The reaction was continued until the acid number of the reaction mixture was 32.8 mg KOH / gm and the melt viscosity at 180° C. was 408 poise.

[0309] The contents of the reaction vessel were then cooled to 200° C., poured out, cooled to room temperature and pulverized into pieces. The reaction product had an acid number of 33.0 mg KOH / gm, a melt viscosity of 393 poise at 180° C., a Tg of 53.7° C., and a weight average molecular weight of 31,255 measured relative to polystyrene standards.

[0310] Polymer F

[0311] Polyesterimide polymer G having acid and hydroxy functionality was prepared from the following ingredients and according to the following procedure:

[0312] A total of 165.5 g of 4,4'-methylenebis(phenyl isocyanate), 200.75 g of trimellitic anhydride, 270 g of 2-methyl-1,3-propanediol (MP diol), 106.5 g of trimethylolpropane, 224 g of terephthalic acid, and 127.5 g of isophthalic acid were added to a suitable reaction vessel equipped with an agitator, a temperature probe, a glycol recovery unit (a packed column and a distillation head connected to a water-cooled condenser), and a nitrogen sparge. The contents of the reaction vessel were carefully heated to 240°C, and continuous water distillation was initiated at 180°C. The contents of the reaction vessel were maintained at 240-245°C, removing water as distillate until the acid number of the reaction mixture reached 8.7 mgKOH / gm. A vacuum was then applied to remove the remaining water while maintaining the contents of the reaction vessel at 240-245°C. Vacuum was applied until the reaction mixture had an acid value of 3.8 mg KOH / gm and a melt viscosity of 254 poise at 180°C.

[0313] The contents of the reaction vessel were maintained at 240°C and 60 g of adipic acid was added to the reaction mixture. The contents of the reaction vessel were then maintained at 238-242°C until the acid number of the reaction mixture was 27.3 mg KOH / gm.

[0314] The contents of the reaction vessel were cooled to 230°C, then poured out, cooled to room temperature and broken into pieces. The acid value of the reaction product was 25.2 mg KOH / gm and the Tg was 54.6°C.

[0315] Polymer G

[0316] An acidified polyesterimide polymer was prepared from the following ingredients as follows: A total of 1000 g of Polymer A (RP-45-6747) (prepared as described above) and 100.0 g of p-tert-butylbenzoic acid were added to a suitable reaction vessel equipped with an agitator, a temperature probe, a glycol recovery unit (a packed column and a distillation head connected to a water-cooled condenser), and a nitrogen sparge. The contents of the reaction vessel were heated to approximately 160° C. to melt the contents, and then heated to 210° C. with continuous removal of water as distillate. The contents of the reaction vessel were maintained at 208-212° C. with water removed as distillate until the reaction mixture had an acid value of 16.0 mg KOH / gm.

[0317] The contents of the reaction vessel were cooled to 200° C. and 70.0 g of adipic acid was added to the reaction mixture. The contents of the reaction vessel were maintained at 198-202° C. and vacuum was used to facilitate distillation as needed to remove water as distillate. The reaction was continued until the acid number of the reaction mixture was 39.4 mg KOH / gm and the melt viscosity at 180° C. was 122.5 poise.

[0318] The contents of the reaction vessel were cooled to 180°C and a mixture of 4.0 g of tetra-n-butyl titanate and 4.0 g of methoxypropanol was added (they were premixed before addition).

[0319] The contents of the reaction vessel were stirred at 180°C for 45 minutes, then poured, cooled to room temperature and pulverized into pieces. The acid value of the reaction product was 39.4 mg KOH / gm and the melt viscosity at 180°C was 94.5 poise.

[0320] Polymer H

[0321] An acidified polyesterimide polymer was prepared from the following ingredients as follows: A total of 1000 g of Polymer A (RP-45-6747) (prepared as described above) and 100 g of p-tert-butylbenzoic acid were added to a suitable reaction vessel equipped with an agitator, a temperature probe, a glycol recovery unit (a packed column and a distillation head connected to a water-cooled condenser), and a nitrogen sparge. The contents of the reaction vessel were heated to approximately 160° C. to melt the contents, and then heated to 240° C. with continuous removal of water as distillate. The contents of the reaction vessel were maintained at 240-245° C. with water removed as distillate until the reaction mixture had an acid value of 14.7 mg KOH / gm.

[0322] The contents of the reaction vessel were cooled to 180° C. and 60.0 g of trimellitic anhydride was added to the reaction mixture. The contents of the reaction vessel were maintained at 178-182° C. and a small amount of water was removed as distillate until the reaction mixture had an acid number of 47.9 mg KOH / gm and a melt viscosity of 180.2 poise at 180° C.

[0323] The contents of the reaction vessel were cooled to 170°C and a mixture of tetra-n-butyl titanate 20.0 g and methoxypropanol 20.0 g was added (they were premixed before addition).

[0324] The contents of the reaction vessel were then poured out, cooled to room temperature and broken into pieces. The acid number of the reaction product was 46.6 mg KOH / gm and the melt viscosity at 180°C was 163.5 poise.

[0325] Coating Composition Examples 1-7

[0326] Inventive coating compositions 1-7 and comparative coating composition 1 were prepared according to the formulations listed in Table 1. All amounts are given in parts by weight (pbw).

[0327]

[0328] Test Method

[0329] Test Panel Preparation: Coating samples were applied to aluminum panel monolithic cans. 1-2 g of each of coating compositions 1-7 was applied to the aluminum panel by electrostatic spraying using a Corona high-voltage applicator gun. The panel was then cured in a convection oven for 4 minutes at the temperatures shown in Tables 3 and 4. Test Can Preparation: Selected samples of coating compositions 2, 3, 6, and comparative coating compositions 1-4 were applied to aluminum cans by electrostatic spraying using a Corona high-voltage applicator gun. Each can contained 0.6-1.2 g. The cans were then cured in a convection oven for 4 minutes at the temperatures shown in Tables 5-8.

[0330] The coated panels were tested for coating thickness, direct and reverse impact testing, cross-hook adhesion, cross-cut adhesion, blushing, discoloration, scratch resistance, cracking after folding, and adhesion after folding after exposure to boiling water and solvents. The coated cans were tested for coating thickness, glaze rating after impact testing (also known as a drop weight test), cross-hook adhesion, cross-cut adhesion, blushing, discoloration, scratch resistance, cracking after folding, and adhesion after folding after exposure to boiling water and after exposure to deodorant, styling mousse, shaving foam, or hair spray according to the following procedures.

[0331] Coating Thickness: Coating thickness was measured non-destructively using an ISOSCOPEMP 30 coating thickness gauge on an aluminum substrate. Uncoated aluminum panels and cans were used for calibration after being flattened. Coating thickness of coated cans was measured on both the sidewalls and bottom of the can. Measured thickness is reported in micrometers and represents the average of 10 measurements or the lowest and highest values.

[0332] Impact Test: Impact testing was performed according to ASTM D 2794. The panels were placed with the coated side facing up (direct) and facing down (reverse) on a metal fixture. A 1 kg weight was dropped from a height of 60 cm to create an indentation. The bottom part of the coating can was cut at a height of 20 mm and then placed face down on a Teflon-coated fixture. A 1 kg weight was dropped from a height of 1 meter to create an indentation. The integrity of the coating was measured using a WACO Enamel Rater Instrument and a 1% saline solution containing 0.1% dioctyl sodium sulfosuccinate and reported in milliamperes (mA).

[0333] MEK Wipe Test: A cotton ball soaked in methyl ethyl ketone (MEK) is rubbed 100 times. The coated panel or tank part is then tested for scratch resistance, discoloration, post-fold cracking, and post-fold adhesion. The test method is described in

[233] -

[238] . After 100 reciprocal rubs, the color of the cotton ball is checked.

[0334] Boiling Water Test: The coated parts of the panels and cans were immersed in boiling demineralized water at 100°C for 15 minutes and then removed and dried. They were then tested for cross-cut adhesion, cut edge adhesion, haze, discoloration, scratch resistance, post-fold cracking, and post-fold adhesion.

[0335] Cross-cut adhesion is measured according to DIN ISO 2409. Briefly, a grid line is created in the film using a grid comb, which is then covered with adhesive tape (grade TESA 4104 transparent). Within 60 seconds of application, the tape is quickly removed. The grid area is then inspected for removal of the coating from the substrate. Adhesion is scored according to the following scale:

[0336] 0: The cut edge is completely smooth; no grid squares are detached.

[0337] 1: Small pieces of coating detached at intersections; less than 5% of the area is affected.

[0338] 2: Some coating flakes are detached along the edges and / or at the cut intersections. The affected area is 5-15% of the grid.

[0339] 3: The coating peels off along the edges and on some of the grid squares. The affected area is 15-35% of the grid.

[0340] 4: The coating peels off in large strips along the cut edges, and some squares are detached entirely. The affected area is 35-65% of the grid.

[0341] 5: Total peeling and mottling that cannot be classified under 4.

[0342] Cut edge adhesion was measured by the following method. Coated parts of panels and cans were cut along the length of the panels and cans using scissors. Cut edge adhesion was evaluated based on the degree of peeling from the substrate using a scale of 1-5, with 5 being the best.

[0343] Haze is measured by the following method. Tested panels and coated parts of cans are compared to untested control samples. Haze is evaluated using a scale of 1-5, with 5 being the best.

[0344] Discoloration was measured by the following method. Tested panels and coated parts of the can were compared to untested control samples. Discoloration was evaluated using a scale of 1-5, with 5 being the best.

[0345] Scratch resistance is measured by the following method. A sharp-edged plastic device is moved along the surface of the panel and can at a 45° angle. Scratch resistance is evaluated based on the degree of peeling from the substrate and using a scale of 1-5, with 5 being the best.

[0346] Folding cracking is measured by the following method. The coated parts of the panel and can are folded 180 degrees. The folded area is then visually inspected. Cracking is evaluated using a scale of 1-5, with 5 being the best.

[0347] Adhesion after folding was measured by the following method. The coated parts of the panel and can were folded 180°. The folded area was scratched by hand. Adhesion was evaluated using a scale of 1-5, with 5 being the best.

[0348] The packaging properties were measured by the following method. The coated cans were cut into strips and placed in a can serving as a test container. After the can was sealed with a valve, the initially filled contents were transferred. The cans were stored at 55°C for 1 week plus 4 weeks at 45°C. After storage, the cans were opened and the coated strips were immediately tested for cut edge adhesion, haze, discoloration, scratch resistance, cracking after folding, scratch resistance after folding, and blistering. The test methods are described in

[233] –

[238] .

[0349] Blistering was measured by the following method: The coated strips were compared to an untested control sample.

[0350] Foaming was rated using a scale of 1-5, with 5 being the best.

[0351]

[0352]

[0353]

[0354] Attention must be paid to all papers and documents that were filed concurrently with or prior to the application related to this application and that are publicly available to the public as of this application, and the contents of all such papers and documents are incorporated herein by reference.

[0355] All features disclosed in this application document (including any accompanying claims and abstract), and / or all steps of any disclosed method, may be combined in any combination, except combinations in which at least some of such features and / or steps are mutually exclusive.

[0356] Each feature disclosed in this application document (including any accompanying claims and abstract) may be replaced by alternative features serving the same, equivalent, or similar purpose, unless expressly stated otherwise. Therefore, unless expressly stated otherwise, each feature disclosed is only an example of a generic series of equivalent or similar features.

[0357] The invention is not limited to the details of the foregoing embodiments. The invention extends to any novel feature or any novel combination of features disclosed in this application document (including any accompanying claims and abstract), or to any novel step or any novel combination of steps of any disclosed method.

Claims

1. A food and / or beverage container, at least a portion of which is coated with a coating, wherein the coating is derived from a coating composition comprising: a. A polyester imide (PEI) polymer having an acid value ≥10 mg KOH / g; and b. a crosslinking agent which can be used to crosslink the acid functionality on the polyesterimide polymer; wherein the cross-linking agent comprises a hydroxyalkylamide material and / or a hydroxyalkylurea material and / or a carbodiimide resin; wherein the weight ratio of the polyesterimide (a) to the crosslinker (b) of the coating composition is 50:1 to 1:10; wherein the coating composition comprises a pigment and / or filler in an amount of 0-30 wt %, based on the total solid weight of the coating composition; and The coating composition is substantially free of bisphenol A (BPA), bisphenol F (BPF), bisphenol A diglycidyl ether (BADGE), and bisphenol F diglycidyl ether (BFDGE).

2. A monolithic aerosol can and / or tube, at least a portion of which is coated with a coating, wherein the coating is derived from a coating composition comprising: a. A polyester imide (PEI) polymer having an acid value ≥10 mg KOH / g; and b. a crosslinking agent which can be used to crosslink the acid functionality on the polyesterimide polymer; wherein the cross-linking agent comprises a hydroxyalkylamide material and / or a hydroxyalkylurea material and / or a carbodiimide resin; wherein the weight ratio of the polyesterimide (a) to the crosslinker (b) of the coating composition is 50:1 to 1:10; wherein the coating composition comprises a pigment and / or filler in an amount of 0-30 wt %, based on the total solid weight of the coating composition; and The coating composition is substantially free of bisphenol A (BPA), bisphenol F (BPF), bisphenol A diglycidyl ether (BADGE), and bisphenol F diglycidyl ether (BFDGE).

3. A food and / or beverage container according to claim 1 or a one-piece aerosol can and / or tube according to claim 2, wherein the polyesterimide PEI polymer is formed from an imide-containing moiety.

4. The food and / or beverage container or the one-piece aerosol can and / or tube according to claim 3, wherein the imide-containing moiety comprises a cyclic imide group.

5. A food and / or beverage container or a one-piece aerosol can and / or tube according to any preceding claim, wherein the polyesterimide polymer has a Tg of 40-70°C.

6. A food and / or beverage container or a one-piece aerosol can and / or tube according to any preceding claim, wherein the coating composition is a thermosetting powder coating composition.

7. A food and / or beverage container or a one-piece aerosol can and / or tube according to any preceding claim, wherein the composition comprises a titanate material.

8. A food and / or beverage container or a monolithic aerosol can and / or tube according to claim 7, wherein the titanate material comprises a titanate substituted with organic groups, each of the organic groups being independently selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, pentyl, hexyl, cyclohexyl.

9. A food and / or beverage container or a monolithic aerosol can and / or tube according to claim 7 or 8, wherein the titanate material is present in the coating composition in an amount of 0.1 to 10 wt%, based on the dry weight of the coating ingredients.

10. A method for preparing an acid-functional polyesterimide polymer having an acid value ≥ 10 mg KOH / g; the method comprising the steps of: a. forming a polyester imide polymer; b. contacting the polyesterimide polymer with a blocking agent such as a monoacid functional blocking agent; c. contacting the polyesterimide polymer with an acidifying component which may be selected from a diacid or polyacid or an ester or anhydride thereof; d. Optionally contacting the polyesterimide with a titanate material and an optional support.

11. The method according to claim 10, wherein the blocking agent is adapted to react with hydroxyl groups.

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