Polymer having unsaturated cycloaliphatic functionality and coating compositions formed therefrom

TECHNICAL FIELD [0001] This invention relates to a polymer and coating compositions containing a polymer.

BACKGROUND [0002] Applying coatings to metals to stop or inhibit corrosion is well established. This particularly applies to the area of ​​packaging containers, such as metal cans for food and beverages. Coatings are typically applied to the inner part of such containers to prevent the contents from contacting with the container metal. Contact between the metal and the packaged product may corrode the metal container, which may contaminate the packaged product. This is particularly important when the contents of the container are chemically aggressive. Protective coatings are also used on the inner part of the food and beverage containers to prevent corrosion in the free space in the container between the filling line of the food product and the lid of the container.

[0003] WO 2008/036629 describes food and beverage containers comprising a metal substrate that is at least partially coated with a coating prepared from a composition that includes a resin system, a crosslinker and a catalyst.

[0004] Packaging wraps should preferably be able to be quickly applied to the substrate and provide the necessary properties after hardening, for the purpose of the intended use of the product. For example, coatings should be safe in contact with food, should not adversely affect the taste of packaged food or drink, should have excellent adhesion to the substrate, be resistant to dyes and other coating defects, such as "popping" ), "Blushing" and / or blistering, and should be resistant to degradation for a long period of time, even if they are exposed to severe conditions. In addition, the coatings should typically be able to maintain the integrity of the respective film during production of the container and should be able to cope with the processing conditions,

[0005] Various coatings have been used as the protective coatings inside the can, including epoxy based coatings and polyvinyl chloride coatings. However, each of these coating types has potential shortcomings. For example, recycling of polyvinyl chloride-containing materials or related halogen-containing vinyl polymers can be problematic. There is also a need by some to reduce or eliminate certain epoxide compounds commonly used to form epoxy-coatings in contact with food.

[0006] Referring to the aforementioned shortcomings, the packaging coating industry sought coatings based on alternative binding systems, such as polyester resin systems. However, it was problematic to formulate a polyester-based coating that exhibits the required balance of coating properties (eg flexibility, adhesion, corrosion resistance, stability, crack resistance, etc.). For example, there is usually a trade-off between corrosion resistance and the production properties of such coatings. Polyester-based coatings, suitable for contact with food, which have both good production properties and no cracks, are rather too soft and have inadequate corrosion resistance. And vice versa, polyester-based coatings, suitable for contact with food,

[0007] The market demand is an improved binding system for use in coatings such as, for example, packaging coatings.

SUMMARY [0008] The present application claims an article according to any one of claims 1 to 17 and 20, a coating composition according to claim 18 and a method according to claim 19.

[0009] In one aspect, the present invention provides a binder system comprising a polymer having unsaturated cycloaliphatic groups, including a double bond, more preferably a carbon-carbon bond, located between ring atoms. The polymer contains at least one, and more preferably a plurality of unsaturated cycloaliphatic groups. In one embodiment, at least one of the unsaturated cycloaliphatic groups is at least bicyclic (i.e., polycyclic) and more preferably is bicyclic. The polymer may have any suitable skeleton configuration. In preferred embodiments, the backbone comprises at least one heteroatom, with a polyester, a polyether, a polyurethane, and copolymers thereof, being a particularly preferred configuration of the backbone.

[0010] In a further aspect, the invention provides a coating composition useful for coating a variety of articles, including metal articles, such as, for example, metal packaging articles. Some preferred coating compositions of the invention are particularly useful in the coating of metal cans for food and beverages, including the use as a coating on the interior of their food contact surfaces. The coating composition comprises a binding polymer according to the invention (preferably at least in film-forming amount), a cross-linking agent and an optional carrier. The crosslinking agent includes at least one phenolic crosslinking agent. In some embodiments, the polymer of the invention may be self-crosslinking.

[0011] In yet another aspect, the invention provides an article coated on at least part of one of the surfaces with the coating composition described herein. In some embodiments, the coated article includes a packaging article such as a metal food or beverage can or portion thereof having at least a portion of the main surface of the metal substrate (e.g., metal body substrate and / or end portion) coated with the coating composition of the invention.

[0012] In yet another aspect, the invention provides a method of making a coated article. The method includes providing the coating composition described herein and applying the coating composition to at least a portion of the substrate (usually a flat metal substrate) before or after forming the substrate in a packaging article, such as a food or beverage can or portion thereof.

[0013] The above summary of the present invention should not be seen as a description of each disclosed embodiment or each implementation of the present invention. The following description further illustrates the explanatory embodiments. In several places throughout the application, guidelines are provided through a list of examples, which examples can be used in various combinations. In any case, the list provided serves only as a representative group and should not be interpreted as an exclusive list.

[0014] The details of one or more embodiments of the invention are defined in the description below. Other features, objects and advantages of the invention will become apparent from the description and from the patent claims.

SELECTED DEFINITIONS [0015] Unless otherwise specified, the following terms used herein have the meaning given below.

[0016] The term "aliphatic group" means a saturated or unsaturated linear or branched hydrocarbon group that may contain optional elements other than carbon and hydrogen. The term includes, for example, alkyl, alkenyl and alkynyl groups. The term "cyclic group" means a closed-chain hydrocarbon group that is classified as a cycloaliphatic group or an aromatic group, both of which may contain heteroatoms. The term cycloaliphatic group means an organic group that contains a ring that is not an aromatic group.

[0017] The group, which may be the same or different, is referred to as "independent". Substitution of the organic groups of the compounds of the present invention is envisaged. In order to simplify the discussion and exchange of a certain terminology used in this application, the terms "group" and "moiety" are used to distinguish between chemical compounds that allow substitution or which can be substituted and those that do not allow or they can not be substituted in this way either. Accordingly, when the term "group" is used to describe a chemical substituent, the described chemical material includes an unsubstituted group and this group with O, N, Si or S atoms, e.g. in a chain (such as an alkoxy group), and also carbonyl groups or other conventional substituents. In case of, when the term "functional group" is used to describe a chemical compound or a substituent, it is intended to include only unsubstituted chemical material. For example, the expression "alkyl group" is intended to include not only pure alkyl substituents of an open chain saturated hydrocarbon such as methyl, ethyl, propyl, t-butyl and the like, but also alkyl substituents having additional substituents known in the art, such as hydroxyl, alkoxy, alkylsulfonyl, halo, cyano, nitro, amino, carboxy, etc. Accordingly, the "alkyl" group includes ether, haloalkyl, nitroalkyl, carboxyalkyl, hydroxyalkyl, sulfoalkyl, etc. On the other hand, the expression "alkyl functional group" is limited considering only the pure alkyl substituents of an open chain saturated hydrocarbon such as methyl, ethyl, propyl, t-butyl and the like. As used herein, the term "group" is intended to refer to both a particular functional group and also to refer to a broader class of substituted and unsubstituted structures that contain a functional group.

[0018] The term "substantially free" from a particular mobile compound means that the compositions of the invention contain less than 100 parts per million (ppm) of said mobile compound. The term "substantially free" from a particular mobile compound means that the compositions of the invention contain less than 10 ppm of said mobile compound. The term "substantially completely free" from a particular mobile compound means that the compositions of the invention contain less than 1 ppm of said mobile compound. The term "completely free" from a particular mobile compound means that the compositions of the invention contain less than 20 parts per billion (ppb) of said mobile compound.

[0019] The term "mobile" means that the compound can be isolated from the cured coating when the coating (usually about ~ 1 mg / cm thick)² (6.5 mg / in²)) is exposed to the test medium for certain specific conditions, depending on the intended use of the product. An example of these test conditions is to expose the cured coating to HPLC-grade acetonitrile for 24 hours at 25 ° C. If the above phrases are used without the term "mobile" (e.g. "substantially free of XYZ"), the compositions of the present invention contain less than the above-mentioned amount of compound, regardless of whether the compound is mobile in the coating or associated with the coating component.

[0020] The term "cross-linking agent" refers to a molecule capable of forming a covalent bond between polymers or between two different regions of the same polymer.

[0021] The term "on" used in the context of a coating applied to a surface or substrate, includes both coatings applied directly or indirectly to the surface or substrate. Accordingly, for example, the coating applied to the primer coat covering the substrate is a coating applied to the substrate.

[0022] Unless otherwise stated, the term "polymer" includes both homopolymers and copolymers (i.e., polymers with two or more different monomers). Similarly, unless otherwise indicated, the use of the term designating a class of polymers, such as for example "polyester", is intended to include both homopolymers and copolymers (e.g., polyether-urethane polymers). [0023] The term "unsaturated" when used in the context of a compound refers to a compound that contains at least one non-aromatic double bond.

[0024] The term "comprises" and its variants have no limiting significance where the terms appear in the specification and claims.

[0025] The terms "preferred" and "preferably" refer to embodiments of the invention that may provide certain advantages under certain circumstances. However, other embodiments may also be preferred in the same or other circumstances. Furthermore, mentioning one or more preferred embodiments does not mean that other embodiments are not useful, and are not intended to exclude other embodiments from the scope of the invention.

[0026] As used herein, ("a", "an" "the" in English) "at least one" and "one or more" are used interchangeably. Thus, for example, a coating composition that includes an "additive" (in the English version "an" additive) can be interpreted in such a way that the coating composition contains "one or more" additives.

Also, as used herein, mentioning numerical ranges by endpoints includes all numbers included in this range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5 , etc.). Further, the disclosure of the scope includes the disclosure of all subranges included in a broader scope (e.g., 1 to 5 discloses 1 to 4, 1.5 to 4.5, 1 to 2, etc.).

DETAILED DESCRIPTION [0028] In one aspect, the invention provides a polymer having an unsaturated cycloaliphatic ("UC") functional group. As used herein, the expression "unsaturated cycloaliphatic" or "UC" refers to a group that (i) contains one or more unsaturated cycloaliphatic groups and (ii) may contain one or more other groups (e.g., as substituents of an unsaturated cycloaliphatic group) . As such, the term includes both unsaturated monocyclic groups and unsaturated polycyclic groups. The polymer contains at least one, and more preferably a plurality of, backbone UC groups having a double bond located between ring atoms, which is preferably a substituted or unsubstituted hydrocarbon ring,

[0029] The double bond is a carbon-carbon double bond, although other types of double bonds (such as, for example, carbon-oxygen double bonds ("C = O"), carbon-nitrogen bonds ("C = N"), nitrogens. nitrogen ("N = N") and nitrogen-oxygen (N = O)) may be used in some embodiments. In some embodiments, the UC group contains two or more carbon-carbon double bonds.

[0030] In another aspect, the invention is a coating composition that comprises a UC functionalized polymer, preferably in a film-forming amount. Although coating compositions other than food contact coating compositions are included within the scope of this invention, the preferred coating compositions of the invention are suitable for use as food contact coatings. It is further contemplated that the coating composition of the invention may be used in various other end-use coating applications, including other packaging coating applications, such as e.g. coating applications in pharmaceutical or medical packaging; the use of an industrial coating such as, e.g., device coatings; coatings for steel products for internal or external construction; use of HVAC coating; coatings for agricultural metal products; wood coatings; e.t.c.

[0031] The coating composition according to the invention preferably comprises a UC functionalized polymer, a crosslinking agent (i.e. a crosslinking phenol resole) and an optional liquid carrier. The coating composition preferably also contains a catalyst (such as e.g. an acid catalyst) to enhance curing and / or crosslinking. Although coating compositions containing a liquid carrier are currently preferred, it is contemplated that the UC functionalized polymer of the invention may be useful in other coating application techniques, such as, for example, powder coating.

[0032] The UC functionalized polymer of the invention may have any suitable framework configuration. Various monomeric blocks may be selected depending on the intended use, including the desired properties of the final product, the expected uses of the polymer composition, other materials with which the polymer composition will be mixed or come into contact, or the type of polymer desired. In presently preferred embodiments, the backbone comprises one or more heteroatoms (e.g., oxygen, nitrogen, silicon, sulfur, phosphorus, etc.), of which the preferred heteroatoms are nitrogen and oxygen. The backbone skeletons (i.e., polymer backbones resulting from a stepwise polymerization process, such as, for example, a condensation polymerization process) are preferred frameworks, which condensation skeletons are particularly preferred. Non-limiting examples of suitable backbones including those with one or more heteroatoms include polyester, polyether, polyurethane backbones and copolymer backbones thereof (e.g., polyester-urethane backbones, polyester-ether backbones, etc.) Some non-limiting examples of polyester-urethane polymers are disclosed in International Application No. PCT / US2009 / 065848 filed on November 25, 2009 and entitled "Polyester Polymer and Coating Compositions Thereof" (Application identification number given by proxy 06-1949-0201). If desired, the backbones may contain one or more oligomeric or polymeric segments formed by a chain polymerization (or addition) process.

[0033] The polyester backbone is particularly preferred. The polyester backbone optionally may contain other step bonds, such as, for example, urethane bonds. In some embodiments, where a polyester backbone is used, the backbone is free of urethane linkages and / or other non-ester step bonds.

[0034] Conventional polyester-based packaging films for contact with food have typically been based on a mixture of a polyester polymer and a cross-linking resin. Such polyesters usually contained relatively few reactive hydroxyl groups and, moreover, the reactive groups of cross-linking resins did not usually show a high tendency to enter into crosslinking reactions with the hydroxyl groups of the polyester. It is believed that after curing, relatively weak crosslinks are formed between the polyester and the crosslinking resin, resulting in a network of self-crosslinkable crosslinking resins having unreacted polyester polymer dispersed therein. These conventional polyester coatings have experienced various performance problems such as poor chemical resistance, lack of flexibility and / or insufficient cracking. (As used herein, the term "crazing" refers to the characteristic coating defects that may occur during the production of a coated metal substrate). At the same time, without wishing to be bound by any theory, it is believed that these coating disadvantages are attributable to the increase in crystallinity of the coating materials that occurs between curing the coatings and the preparation of the coated article. In contrast to conventional polyester contact coatings, preferably the cured coatings according to the invention show a suitable balance of coating properties, including excellent corrosion resistance, excellent production properties and a lack of cracks. which may occur during the production of a coated metal substrate). At the same time, without wishing to be bound by any theory, it is believed that these coating disadvantages are attributable to the increase in crystallinity of the coating materials that occurs between curing the coatings and the preparation of the coated article. In contrast to conventional polyester contact coatings, preferably the cured coatings according to the invention show a suitable balance of coating properties, including excellent corrosion resistance, excellent production properties and a lack of cracks. which may occur during the production of a coated metal substrate). At the same time, without wishing to be bound by any theory, it is believed that these coating disadvantages are attributable to the increase in crystallinity of the coating materials that occurs between curing the coatings and the preparation of the coated article. In contrast to conventional polyester contact coatings, preferably the cured coatings according to the invention show a suitable balance of coating properties, including excellent corrosion resistance, excellent production properties and a lack of cracks.

[0035] At the same time, without wishing to be bound by any theory, it is believed that the excellent balance of coating properties exhibited by some preferred coating compositions of the invention (including e.g. where the UC functionalized polymer has a polyester backbone) is attributed at least in part to one or more of (i) the reactivity of the polymer UC groups, (ii) locating the crosslinking sites throughout the polymer (as opposed to only at the terminal ends, which is typical for conventional polyesters) by incorporating reactive UC groups, (iii) increasing the number of crosslinking sites in a polymer, and / or (iv) a particular choice of crosslinker (crosslinking agents).

[0036] As mentioned above, in preferred embodiments of the invention, the binder polymer comprises one or more (e.g.,> 2,> 3,> 4,> 5,> 10, etc.) backbone groups. Non-limiting examples of UC groups include: substituted or unsubstituted C3-C13 unsaturated rings, and more typically substituted or unsubstituted C4-C9 rings (e.g., unsubstituted or substituted cyclobutenes, cyclopentenes, cyclopentadienes, cyclohexenes, cyclohexadienes, cycloheptenes, cycloheptadienes, cyclooctenes, cyclooctadienes, cyclononenes) , cyclodecenes, cyclodecadienes, cycloundecenes, cyclododecenes, cyclotridecene and cyclone-donadienes and combinations thereof), substituted or unsubstituted unsaturated polycyclic groups (i.e., at least bicyclic groups, more preferably bicyclic groups), and combinations thereof. In some embodiments, the above-mentioned UC groups may contain one or more heteroatoms (e.g., N, O, S, etc.) in the UC ring. In some embodiments, it may be desirable for a UC group to contain one or more allyl hydrogen atoms attached to a ring carbon where the carbon atom is adjacent to a double ring bond.

[0037] Unsaturated groups that are at least bicyclic (e.g. bicyclic, tricyclic or higher order polycyclic) and more preferably bicyclic are preferred UC groups. At least bicyclic groups will usually contain from 5 to 30 carbon atoms, more typically from 6 to 15 carbon atoms, and even more typically from 7 to 10 carbon atoms. The at least bicyclic groups can contain one or more heteroatoms (e.g., N, O, S, etc.) instead of one or more of the above-mentioned carbon atoms. The term "bicyclic" refers to a group that contains two cyclic groups in which one or more (and preferably two or more) atoms are present in the rings of both cyclic groups. So, for example, a group,

[0038] At the same time, without intending to be bound by theory, it is believed that the carbon-carbon double bond present in unsaturated bicyclic groups such as norbornene exhibits increased reactivity. It is believed that the high level of ring stress present in some unsaturated bicyclic groups contributes to increased reactivity. For a further discussion on the reactivity of bicyclic compounds, see, for example, DE Van Sickel, FR Mayo, RM Arluck JACS (32) 1967, 3680 "Bridging of the cyclohexane ring has thoroughly deactivated the allylic bridgehead by 8 is ninefold. " At the same time also not intending to be bound by any theory, it is contemplated that increased reactivity (e.g. between the UC group and the crosslinker) can also be achieved using unsaturated ring groups other than bicyclic groups having a highly stressed ring and, more preferably, a ring stress level greater than that of the cyclohexene group, and most preferably close to or greater than that of the norbornene group. Although ring stresses present in such UC groups may be smaller than for some unsaturated bicyclic groups, for some end applications they may be sufficient. Non-limiting examples of such stretched ring groups include substituted or unsubstituted variants of the following: cyclopropene (e.g. 1,2-dimethylcyclopropene), cyclobutene, trans-cyclooctene, trans-cycloneone, cyclobutadiene, cyclopentadiene, 1,3-cyclohexadienne, 1, 3-cycloheptadiene, 1,3-cyclooctadiene, 1,3-cyclonadadiene and 1,3-cyclodecadienoic acid and their derivatives and combinations. By way of example, a cyclohexene group is generally not considered to be a ring-tensioned group. In the context of a monocyclic ring system, rings containing 3 to 5 atoms, in particular 3 or 4 atoms, tend to exhibit the greatest magnitude of total ring tension. Examples of such systems of tensioned monocylic rings are included in the above list. they tend to exhibit the largest amount of total ring stress. Examples of such systems of tensioned monocylic rings are included in the above list. they tend to exhibit the largest amount of total ring stress. Examples of such systems of tensioned monocylic rings are included in the above list.

[0039] At the same time, without wishing to be bound by theory, in some embodiments, suitable stretched ring groups will preferably have at least one double bond with the hydrogenation heat greater than that of cyclohexene. In some embodiments, the UC group (and preferably the carbon-carbon double bond of the UC group) has a hydrogenation heat that is at least approximately as high as for bicyclo [2.2.2] octene (e.g., 28.25 kcal). mole), and more preferably at least approximately as high as in the case of bicyclo [2.2.1] heptene (e.g. -33.13 kcal / mol). As used herein, when the hydrogenation heat is defined, for example, "at least X", "more than X", or the like, it should be understood that it refers to the absolute value of the hydrogenation heat, since the heat of hydrogenation is usually reported as negative, when a higher negative value indicates a higher hydrogenation heat (e.g. -40 kcal / mol is a higher hydrogenation heat than -10 kcal / mol). It is also contemplated that some reactive aliphatic (or open-chain) carbon-carbon double bonds may be substituted with some or all of the polymer UC groups. Such suitable groups may include carbon-carbon double bonds having, for example, hydrogenation heat, which is (i) higher than for cyclohexene or (ii) at least approximately as high as bicyclo [2.2.2] octene. Preferred reactive carbon-carbon aliphatic double bonds are capable of reacting under curing conditions of the coatings described herein with a suitable crosslinking agent,

[0040] In one embodiment, the UC group includes a bicyclic structure represented by Expression (1) according to the IUPAC nomenclature (International Union of Pure and Applied Chemistry):

bicyclo [xyz] alkene [0041] In Expression (I), x is an integer of 2 or more, y is an integer of 1 or more, z is an integer of 0 or more, and the term alken refers to IUPAC nomenclature designations (e.g.

hexene, heptene, heptadien, octene, etc.) for a given bicyclic molecule and means that the bicyclic group contains one or more double bonds (e.g.> 1,> 2,> 3 double bonds).

[0042] Preferably, in Expression (I) it is 1 or more. In other words, preferred bicyclic groups include a bridge of at least one atom (usually one or more carbon atoms) located between a pair of bridgehead atoms in which at least one atom is common to at least two rings. By way of example, bicyclo [4.4.0] decane does not contain such a bridge.

[0043] In preferred embodiments, x has a value of 2 or 3 (more preferably 2), and each of y and z independently has a value of 1 or 2.

[0044] Non-limiting examples of some suitable UC groups represented by Expression (I) include monovalent or polyvalent (e.g., divalent) bicyclo [2.1.1] hexene, bicyclo [2.2.1] heptene (e.g., norbornene), bicyclo [2.2. 2] octene, bicyclo [2.2.1] heptadien and bicyclo [2.2.2] octadiene. Bicyclo [2.2.1] hepten is currently a preferred UC group.

[0045] It is contemplated that the UC groups represented by Expression (I) may contain one or more heteroatoms (e.g., nitrogen, oxygen, sulfur, etc.) and may be substituted containing one or more additional substituents. For example, one or more cyclic groups (including, for example, side cyclic groups and ring groups fused with a bicyclic group UC ring) or acyclic groups can be attached to the bicyclic group represented by Expression (I). Accordingly, for example in some embodiments, the bicyclic group according to Expression (I) may be present in a tricyclic or higher group.

[0046] If desired, the UC functionalized polymers of the invention may comprise non-cycloaliphatic unsaturation. For example, some of the UC functionalized polymers may contain aliphatic unsaturation (i.e. open chain or linear unsaturation) and / or aromatic unsaturation.

[0047] The iodine value is a useful measure to characterize the average number of non-aromatic double bonds present in the material. The UC functionalized polymer of the invention may have any suitable iodine number to achieve the desired result. In preferred embodiments, the UC functionalized polymers have an iodine value of at least about 10, more preferably at least about 20, more preferably at least about 35 optimally at least about 50. The upper range of the corresponding iodine number values ​​is not limited, but in the majority For example, the iodine number does not typically exceed about 120. The iodine value is usually expressed in terms of iodine centigrams per gram of resin and can be determined

[0048] In some embodiments, the functionalized UC polymer comprises a plurality of UC groups, and more preferably a plurality of unsaturated groups of at least bicyclic (more preferably bicyclic), sufficient to provide an iodine value of at least 5, at least 10, at least 20, at least Or at least (before including in the part of the total iodine value of the polymer assigned to any other carbon-carbon double bonds that may be present in the polymer).

[0049] The UC functionalized polymer of the invention may contain any suitable number of UC groups. As mentioned above, one of the useful measures of such groups is the number of such groups present in the polymer. Another useful measure is the weight percentage of the UC groups relative to the total weight of the polymer. In certain preferred embodiments, the UC groups are at least about 5, more preferably at least about 15, and even more preferably at least about 30 weight percent ("wt%") of the polymer. Preferably, the UC groups are less than about 95, more preferably less than about 75, and even more preferably less than about 50 wt.%. polymer. In some embodiments, such as, for example, when open chain unsaturation is included in the polymer (e.g. using materials such as maleic acid or anhydride), the number of UC groups lower than that mentioned above can be used. In certain preferred embodiments, the functionalized UC polymer comprises a series of at least bicyclic groups, more preferably bicyclic groups, sufficient to achieve wt%. at least bicyclic groups as described above.

[0050] Special care should be taken when interpreting% by weight. UC groups, because direct measurement of the weight of UC groups may not be feasible. Accordingly, the aforementioned% wt. refer to the total weight of (a) UC containing monomers with respect to (b) the total weight of the UC functionalized polymer. Thus, for example, if the oligomer having the UC group is included in the backbone of the polymer, then% wt. the UC group in the polymer is calculated using the weight of the monomer that contains the UC group (as opposed to the weight of the oligomer that contains the monomer). Similarly, if a polymer was formed and then the monomer of this pre-formed polymer was modified to incorporate the UC group, then wt% the UC groups in the polymer are calculated using the weight of the modified monomer, which can be, if necessary, based on theoretical calculations. For example, in some embodiments, bicyclic UC groups can be incorporated into a polymer by the Diels-Alder reaction of cyclopentadiene by double bonding the monomer present in the polymer backbone (e.g., maleic anhydride reacted to the polymer backbone). In this situation,% wt. the UC groups in the polymer are determined by the weight of the resulting modified bicyclic monomer present in the polymer (e.g., the weight of cyclopentadienized maleic anhydride).

[0051] In some preferred embodiments, the UC group is attached to at least one other portion of the polymer via a step bond (e.g., condensation bond) such as for example an amide, carbamate, carbonate ester (-OC (= O) -O bond group) -), ester, ether, urea or urethane. A covalent bond, formed for example in an addition polymerization reaction (e.g., free radical addition polymerization such as vinyl polymerization), is not considered to be a step bond. Ester bonds are currently preferred gradual bonds. If desired, other bonds of organic groups may also be used, such as, for example, substituted or unsubstituted bond of hydrocarbyl groups.

[0052] As mentioned before, in some preferred embodiments, the UC functionalized polymer has a polyester backbone. In one such embodiment, the UC functionalized polyester polymer comprises at least one divalent skeleton UC group that is connected at each end to a different portion of the backbone via a step bond, more preferably an ester bond.

[0053] Suitable polyester polymers can be prepared by standard condensation reactions. The polyester polymer usually originates from a mixture of at least one polyfunctional alcohol ("polyol") esterified with at least one polycarboxylic acid (or a derivative thereof). In some embodiments, transesterification polymerization or other process may be used. If desired, the polyester polymer may contain polymeric bonds (e.g., amide, carbamate, carbonate ester, ether, urea, urethane, etc.), side chains, and end groups that are not bonded to the simple components polyol and polyacid.

Non-limiting examples of suitable polycarboxylic acids include dicarboxylic acids and polycarboxylic acids having higher acidic functional groups (e.g., tricarboxylic acids, tetracarboxylic acids, etc.) or anhydrides, precursors or derivatives thereof (e.g., an esterizable polycarboxylic acid derivative, e.g. dimethyl ester or anhydride) or mixtures thereof. Suitable polycarboxylic acids may include, for example, maleic acid, fumaric acid, succinic acid, adipic acid, phthalic acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, hexahydrophthalic acid, methylhexahydrophthalic acid, endomethylene-tetrahydrophthalic acid, azelaic acid, sebacic acid, isophthalic acid. , trimellitic acid, terephthalic acid, naphthalene dicarboxylic acid, cyclohexanedicarboxylic acid, glutaric acid, dimeric fatty acids, their anhydrides or derivatives, and mixtures thereof. If desired, adducts of polyacids (e.g., triacids, tetraacids, etc.) and monofunctional compounds can be used. An example of one of such adducts is pyromellitic anhydride pre-reacted with benzyl alcohol. It should be understood that in the synthesis of polyester, certain acids may exist in the form of anhydrides, esters (e.g., alkyl esters) or in a similar equivalent form. For the sake of brevity, such compounds are referred to herein as "carboxylic acids". An example of one of such adducts is pyromellitic anhydride pre-reacted with benzyl alcohol. It should be understood that in the synthesis of polyester, certain acids may exist in the form of anhydrides, esters (e.g., alkyl esters) or in a similar equivalent form. For the sake of brevity, such compounds are referred to herein as "carboxylic acids". An example of one of such adducts is pyromellitic anhydride pre-reacted with benzyl alcohol. It should be understood that in the synthesis of polyester, certain acids may exist in the form of anhydrides, esters (e.g., alkyl esters) or in a similar equivalent form. For the sake of brevity, such compounds are referred to herein as "carboxylic acids".

[0055] Non-limiting examples of suitable polyols include diols, polyols having 3 or more hydroxyl groups (e.g., triols, tetraols and the like), and combinations thereof. Suitable polyols may include, for example, ethylene glycol, propylene glycol, 1,3-propanediol, glycerol, diethylene glycol, dipropylene glycol, triethylene glycol, trimethylolpropane, trimethylol ethane, tripropylene glycol, neopentyl glycol, pentaerythritol, 1,4-butanediol, hexylene glycol, cyclohexanedimethanol, polyethylene or polypropylene glycol, isopropylidene-bis (p-phenylene-oxypropanol-2), and mixtures thereof. If desired, adducts of polyol compounds (e.g., triols, tetraols, etc.) and monofunctional compounds can be used. An example of one of such adducts is dipentaerythritol prereacted with benzoic acid.

[0056] In some embodiments, the backbone of the polyester polymer is terminated with a hydroxyl group and / or is terminated with a carboxyl group, more preferably is terminated with a hydroxyl group.

[0057] The polyester polymer may comprise polymer segments other than polyester segments. Typically, however, at least 50 wt. The polyester will contain polyester segments. In some embodiments, substantially all (e.g.,> 80 wt%,> 90 wt%,> 95 wt%, etc.), or all of the polyester contains polyester segments.

[0058] The polyester polymer may have any suitable hydroxyl number. Hydroxyl numbers are usually expressed as milligrams of potassium hydroxide (KOH) equivalent to the content of hydroxyl groups in 1 gram of a substance containing hydroxyl groups. Methods for determining hydroxyl numbers are well known in the art. See, for example, ASTM D1957-86 (Revised in 2001) titled "Standard Test Method for the Hydroxyl Value of Fatty Oils and Acids" and provided by the American Society for Testing and Materials International of West Conshohocken, Pennsylvania. In certain preferred embodiments, the polyester polymer has a hydroxyl number of from 0 to about 150, more preferably from about 5 to about 100, optimally from about 10 to about 80.

[0059] The polyester polymer may have any suitable acid number. The acid numbers are usually expressed as KOH milligrams required to titrate a 1 gram sample to a specific endpoint. Methods for determining acid numbers are well known in the art. See, for example, ASTM D974-04 titled "Standard Test Method for Acid and Base Number by Color-Indicator Titration" and made available by the American Society for Testing and Materials International of West Conshohocken, Pennsylvania. The range of suitable acid numbers may vary depending on various factors, including, for example, whether dispersibility in water is desired. In some embodiments, the polyester polymer has an acid number of at least about 5, more preferably at least about 15, and even more preferably at least about 30.

[0060] In some embodiments, the polymer comprises one or more urethane linkages, and more preferably many urethane linkages (e.g.,> 2,> 3,> 4,> 5,> 10, etc.). of these embodiments, the polymer is a polyurea-urethane polymer. Urethane linkages are usually formed by the reaction of components that include one or more compounds with a hydroxyl functional group and one or more compounds with an isocyanate functional group. If desired, the polyester-urethane polymer may be formed, for example, by reaction of a polyester polyol and a diisocyanate or other polyisocyanate compound.

[0061] The isocyanate compound can be any suitable compound, including an isocyanate compound having an isocyanate group; a polyisocyanate compound having 2, 3 or 4 or more isocyanate groups; or their mixtures. Suitable diisocyanates may include isophorone diisocyanate (e.g., 5-isocyanato-1-isocyanatomethyl-1,3,3-trimethylcyclohexane); 5-isocyanato-1- (2izocyjanianoet-1-yl) -], 3,3-trimethylcyclohexane; 5-isocyanato-1- (3-izocyjanianoprop1-yl) -1,3,3-trimethylcyclohexane; 5-isocyanato (4-izocyjanianobut-1-yl) -1,3,3trimetylocykloheksan; 1-isocyanato-2- (3-izocyjanianoprop-1-yl) cyclohexane;

1-isocyanato-2- (3-izocyjanianoet-1-yl) cyclohexane; 1-isocyanato-2- (4izocyjanianobut-1-yl) cyclohexane; 1,2-diizocyjanianocyklobutan; -1,317 diisocyanatocyclobutane; 1,2-diizocyjanianocyklopentan; 1,3-diizocyjanianocyklopentan; 1,2-cyclohexane diisocyanate; 1,3-cyclohexane diisocyanate; 1,4diizocyjanianocykloheksan; 2,4'-dicyclohexylmethane diisocyanate; trimethylene diisocyanate; tetramethylene diisocyanate; pentamethylene diisocyanate; hexamethylene diisocyanate; ethylene ethylene diisocyanate; trimethylhexane diisocyanate; heptamethylene diisocyanate; 2-heptyl-3,4-bis (9-izocyjanianononylo) -1-pentyl-cyclohexane; 1,2-, 1,4 and 1,3-bis (isocyanatomethyl) cyclohexane; 1,2-, 1,4- and 1,3-bis (2-isocyanatoethyl-1-yl) cyclohexane; 1,3-bis (3-izocyjanianoprop-1-yl) cyclohexane; 1,2-, 1,4- or 1,3-bis (4-isocyanatobut-1-yl) cyclohexane; liquid bis (4-isocyanatocyclohexyl) methane; and their derivatives or mixtures.

[0062] In some embodiments, the isocyanate compounds are preferably non-aromatic. Non-aromatic isocyanates are particularly desirable for coating compositions intended to be used on the inner surface of a food or beverage container. Isophorone diisocyanate (IPDI) and hexamethylene diisocyanate (HMDI) are preferred non-aromatic isocyanates.

If water dispersibility is desired, the UC functionalized polymer may be made dispersible in water using any suitable methods, including the use of non-ionic water-dispersible groups, salts (e.g., anionic and / or cationic salts), surfactants active or their combination. Preferred water-dispersible UC functionalized polymers contain a suitable amount of salt-containing groups (e.g., cationic and / or anionic salts) and / or salt-forming groups to facilitate the preparation of an aqueous dispersion or solution. Suitable salt-forming groups may include groups that can be neutralized, such as acidic and basic groups. At least a portion of the salt-forming groups may be neutralized to form salts useful in the dispersion of the polymer in a water carrier. Acid or basic acid forming groups can be introduced into the polymer using any suitable method. [0064] Non-limiting examples of anionic salt groups include neutralized acid or anhydride groups, sulphate groups (-OSO3^-), phosphate groups (-OPO3^-), sulfonate groups (-SO 2 O.^-), phosphinate groups (-POO^-), phosphonate groups (-PO3^-) and their combinations. Non-limiting examples of suitable cationic salt groups include:

(hereinafter, respectively, quaternary ammonium groups, quaternary phosphonium groups and tertiary sulfate groups) and combinations thereof. Non-limiting examples of nonionic water-dispersible groups include hydrophilic groups such as ethylene oxide groups. Compounds for introducing the aforementioned groups into polymers are known in the art.

[0065] In some embodiments, the water-dispersible functionalized UC polymer can be obtained by incorporating a sufficient number of carboxylic acid groups into the polymer. Non-limiting examples of suitable materials for incorporating such groups into a polymer include anhydrides or poly-adjuvants such as tetrahydrophthalic anhydride, pyromellitic anhydride, pyromellitic dianhydride, succinic anhydride, trimellitic anhydride ("TMA"), and mixtures thereof. In one embodiment, a hydroxyl-terminated polyester polymer or oligomer having one or more hydroxyl side groups is reacted with an anhydride such as TMA to form a hydroxyl terminated polyester having a carboxyl functional group. The reaction conditions are preferably controlled, including temperature, to avoid gelation. The resulting oligomer or polyester polymer with a carboxylic function is neutralized (e.g., with a base such as an amine) to form an aqueous dispersion. In some embodiments, it is contemplated that water dispersibility can be provided by using ethylenically unsaturated acid functional monomers that have been seeded on the polymer, whereupon the appropriate number of acid functional groups has been neutralized with a base (such as e.g. a tertiary amine) to form salt groups. See, for example, U.S. Patent Application No. 20050196629 for examples of such techniques. In some embodiments, it is contemplated that water dispersibility can be provided by using ethylenically unsaturated acid functional monomers that have been seeded on the polymer, whereupon the appropriate number of acid functional groups has been neutralized with a base (such as e.g. a tertiary amine) to form salt groups. See, for example, U.S. Patent Application No. 20050196629 for examples of such techniques. In some embodiments, it is contemplated that water dispersibility can be provided by using ethylenically unsaturated acid functional monomers that have been seeded on the polymer, whereupon the appropriate number of acid functional groups has been neutralized with a base (such as e.g. a tertiary amine) to form salt groups. See, for example, U.S. Patent Application No. 20050196629 for examples of such techniques.

[0066] The molecular weight of the UC functionalized polymer according to the invention may vary depending on the material selection and the desired end use. In preferred embodiments, the polymer has a number average molecular weight (Mn) of at least about 1000, more preferably at least about 1500, and even more preferably at least about 3000. Preferably, the Mn of the polymer is less than about 20,000, more preferably less than about 15,000. and even more preferably less than about 10,000.

[0067] The coating compositions of the invention may contain any suitable amount of a UC functionalized polymer to obtain the desired result. In a preferred embodiment, the coating composition comprises from about 50 to about 100 wt. a UC functionalized polymer, more preferably at least 60 wt.% a UC functionalized polymer, and even more preferably at least 70 wt.%. a UC functionalized polymer based on the total weight of the non-volatile coating composition. Preferably, the coating compositions contain less than about 99, more preferably less than about 95, and even more preferably less than about 80% by weight. a UC functionalized polymer based on the total weight of the non-volatile coating composition.

[0068] Preferred UC functionalized polymers and / or coating compositions of the invention are preferably substantially free, more preferably substantially free, even more preferably essentially completely free and optimally completely free of mobile bisphenol A (BPA) and aromatic compounds of glycidyl ethers (e.g. diglycidyl ethers) bisphenol (BADGE), diglycidyl ethers of bisphenol F (BFDGE) and epoxy novolaks). In some embodiments, the UC functionalized polymer and / or coating compositions of the invention are preferably substantially free, more preferably substantially free, more preferably substantially completely free, and optimally completely free of bound BPA and glycidyl ether aromatic compounds (e.g., BADGE, BFDGE and novolacs) epoxy).

[0069] In some embodiments, the UC functionalized polymer and / or the coating composition is at least substantially "epoxy-free", more preferably "epoxy-free". The term "epoxide free", when used in the context of a polymer, refers to a polymer that does not contain any "epoxy skeleton segments" (i.e. segments formed by the reaction of an epoxy group and an epoxy-reactive group). Accordingly, for example, a polymer prepared from components including an epoxy resin could not be considered epoxide free. Similarly, a polymer having backbone segments that are a reaction product of bisphenol (e.g., bisphenol A, bisphenol F, bisphenol S, 4,4'-dihydroxybisphenol, etc.) and halohydrin (e.g., epichlorohydrin) could not be considered epoxide free. However, vinyl polymers formed from vinyl monomers and / or oligomers that contain epoxy functional groups (e.g., glycidyl, methacrylic) could be considered epoxide free since vinyl polymers would be free of epoxy skeletal segments. The coating composition according to the invention is also preferably at least substantially free of epoxide, more preferably free of epoxide.

[0070] In some embodiments, the UC functionalized polymer is & quot; PVC free & quot; and preferably the coating composition is also & quot; PVC free. & Quot; That is, each composition preferably contains less than 2 wt%. vinyl chloride materials, more preferably less than 0.5 wt.% vinyl chloride materials, and even more preferably less than 1 ppm vinyl chloride materials.

[0071] The UC functional groups can be incorporated into the polymer of the invention by any suitable means. For example, a functional group may be provided by one of the following non-limiting approaches: (A) forming a polymer from a mixture of reagents comprising one or more reagents having a UC group or (B) modifying a pre-formed oligomer or polymer to contain a UC group.

[0072] Non-limiting examples of reagents having a UC group include those with a UC group having one or more active hydrogen groups, such as, for example, acids or anhydrides (e.g., 5-norbornene-2,3-dicarboxylic acid or 5-norbornene-2-anhydride) , 3-dicarboxylic acid, methyl-5-norbornene-2,3-dicarboxylic acid or methyl-5-norbornene-2,3-dicarboxylic acid anhydride, tetrahydrophthalic acid or tetrahydrophthalic acid anhydride, methyltetrahydrophthalic acid or methyl-tetrahydrophthalic anhydride, and mixtures thereof) . The functionalized UC anhydrides are currently preferred, and anhydrides having an unsaturated bicyclic group are particularly preferred. Non-limiting examples of other suitable active hydrogen groups include those having a hydrogen atom attached to an oxygen atom (O),

[0073] A non-limiting example of the above approach (B) includes the steps of:

1. providing a polymer (e.g., polyester polymer) having reactive functional groups capable of participating in a stepwise reaction, such as, for example, carboxyl, hydroxyl, amine, carbonate, isocyanate, or mixtures thereof;

2. providing a compound having (i) a UC group and (ii) a functional group capable of reacting with the above-mentioned polymer functional group to form a step bond, such as for example ester, amide, urethane, urea, urethane or carbonate ester linkages; and

3. reacting the polymer and the aforementioned compound to form a polymer comprising a UC group.

[0074] A further non-limiting example of the above approach (B) involves providing a pre-formed unsaturated oligomer or polymer and applying a Diels-Alder reaction to modify the oligomer or polymer (e.g., using cyclopentadiene or dicyclopentadiene) to incorporate the unsaturated bicyclic group. Materials and methods for the preparation of the bicyclic DielsAlder reaction product are discussed in WO 2008/124682. Non-limiting examples of other useful Diels-Alder reagents may include anthracene, cyclohexadiene, cyclopentadiene (including, e.g., 1-alkyl-cyclopentadienes or 2-alkyl-cyclopentadienes), furan, thiophene, and combinations thereof.

[0075] In some embodiments, it may be advantageous to provide a polymer polyol, such as for example a polyester polyol with a Mn of about 500 to about 5000, and reacting the polymeric polyol with a dianhydride to increase the molecular weight. In some embodiments, the molar ratio of the polymer polyol (e.g., polyester polyol) to the dianhydride is from about 5: 1 to about 50: 1, and more preferably from about 15: 1 to about 25: 1. The reaction is preferably controlled to avoid gelation. For example, the reaction temperature is preferably maintained at a temperature below about 150 ° C (more preferably from about 90 ° C to about 120 ° C) to avoid gelation. Non-limiting examples of suitable dianhydrides include a pyromellitic acid dianhydride, a naphthalene tetraacetic acid dianhydride derivative, benzophenonetetracarboxylic acid diasthydride, diphenyltetracarboxylic acid dihydrate, dianhydrate of butanetetracarboxylic acid, dihydrate of cyclobutanetetracarboxylic acid, dihydrate of cyclopentanetetracarboxylic acid, and combinations thereof. In some embodiments, the UC functionalized polymer of the invention comprises one or more dianhydrides in an amount of from about 0.5 to about 70 wt%, more preferably from about 2 to about 40 wt%, and even more preferably from about 3 to about 10 wt.%, based on the total weight of non-volatile reagents.

[0076] In some polyester-based embodiments, the coating composition of the invention may comprise one or more saturated or unsaturated polyester polymers in addition to the functionalized polyester polymer of the invention. In some such embodiments, at least the majority (e.g.> 50 wt%,> 60 wt%,> 75 wt%,> 90 wt%, etc.), and more preferably all or substantially all of the total amount The polyester polymers contained in the coating composition are UC functionalized polyester polymers.

[0077] In some embodiments, the coating composition of the invention is free or substantially free (e.g., contains less than about 1 wt% based on solid materials) from one or both of acrylic resins or acrylated polyester resins.

[0078] The concentration of one or more optional crosslinkers, if present, in the coating composition may vary depending on the desired result. For example, in some embodiments, the coating composition may contain from about 0.01 to about 50 wt%, more preferably from about 5 to about 50 wt%, more preferably from about 10 to about 40 wt%, and optimally from about 15 to 30 wt% one or more cross-linking agents based on the weight of the non-volatile material in the coating composition.

[0079] Any suitable crosslinking agent or combination of crosslinking agents may be used. For example, phenolic crosslinking agents (e.g., phenoplasts), amine crosslinking agents (e.g., aminoplasts), blocked isocyanate crosslinking agents, epoxide functionalized crosslinking agents, and combinations thereof can be used. Preferred crosslinking agents are generally at least free, more preferably completely free of bound BPA and aromatic glycidyl ethers.

[0080] Examples of suitable phenol crosslinkers include reaction products of aldehydes with phenols. Preferred aldehydes are formic aldehyde and acetaldehyde. Non-limiting examples of suitable phenols that may be used include phenol, cresol, p-phenylphenol, p-tert-butylphenol, p-tert-amylphenol, cyclopentylphenol, cresolic acid, BPA (currently not preferred), and combinations thereof.

[0081] Phenolic resol-type cross-linking agents are currently preferred for certain applications of coatings for foodstuffs or beverages, and in particular for coatings in contact with food. At the same time, without wishing to be bound by theory, it has been observed that cured packaging coatings formulated using a UC functionalized polymer according to the invention and one or more resole crosslinking phenolic agents (with additional crosslinking agents such as, e.g. non-resol phenolic crosslinkers, amino crosslinking agents and / or blocked isocyanate crosslinkers, or without them), have better coating properties orfor comparable cured packaging coatings formulated without the use of resol type phenol crosslinkers. In preferred embodiments, it is believed that once cured, the phenolic resole crosslinks form a covalent bond to the UC group of the UC functionalized polymer, resulting in the formation of a crosslinked polymer network containing both a phenolic crosslinker and a UC functionalized polymer. At the same time, without wishing to be bound by any theory, it is believed that this corresponds, at least in part, to improved coating properties exhibited by some preferred packaging coatings of the invention with respect to some conventional packaging coatings containing, for example, polyester and phenolic resins that do not form, or they do not make up much,

According to the present invention, the coating composition of the invention comprises (i) a UC functionalized polymer, more preferably a UC functionalised polyester polymer having unsaturated at least bicyclic groups (more preferably bicyclic groups of UC) and (ii) at least one crosslinking resole crosslinker phenol. At the same time, without wishing to be bound by theory, it is believed that the UC group and the phenol resolver crosslinking react with one another during the curing of the coating to form a covalent bond between the UC functionalized polymer and the phenol crosslinking polymer.

[0083] At the same time, without intending to be bound by any theory, a simplified Diagram (I) is provided below illustrating the reaction that is believed to occur between the UC group and the phenolic resole under the respective reaction conditions.

<img file="PL2416962T3_D0001.tif" />

[0084] In the above Diagram (I), dotted lines were added to illustrate the proposed reaction mechanism; R and R 'show other structural parts of the phenolic crosslinking agent; and the backbone of the bicyclic UC group (and in particular the backbone of the norbornyl group) was added as an illustrative UC group. As shown in Diagram (I), it is believed that two valence bonds are formed and are believed to be present in the so-called "Chroman Ring", which is marked in bold in Diagram (I) and contains the aromatic ring of the phenolic crosslinker and a ring that it is believed that it is formed between a phenolic aromatic group and a group

UC. Accordingly, in some embodiments, it is believed that two covalent bonds arise between the UC group and the phenolic crosslinker, one of which is an ether linkage group and the other is a hydrocarbyl bonded group (e.g., divalent methylene group). It is believed that the group joining the Chroman Ring causes the coating to have better properties. In addition to bicyclic groups

UC, it is believed that the Chroman Ring may also be formed when monocyclic UC and / or tricyclic or higher polycyclic UC groups are used. It is also contemplated that some open-chain carbon-carbon double bonds may be capable of participating in a similar reaction with the crosslinking phenol resole to form valence bonds between the binding polymer and the phenolic crosslinking agent.

[0085] Non-limiting examples of suitable crosslinking phenolic resols include DUREZ 33160 and 33162 (both available from Durez Corporation, Addison, Texas), BAKELITE 6535 and 6470 (both available from Hexion Specialty Chemicals

GmbH), PHENODUR PR 285 and PR 812 products (both available from CYTEC Surface Specialties, Smyrna, Georgia) and SFC 112 and 142 products (both available from SI Group, previously Schenectady), and mixtures thereof. In some embodiments, the coating composition comprises, relative to a total solids content, at least about 5, more preferably at least about 10, and even more preferably at least about 15 wt%. a phenolic crosslinking agent. Preferably, some or all of the phenolic crosslinkers are crosslinking phenolic resols.

[0086] Amine crosslinking resins (e.g., aminoplasts) are typically condensation products of aldehydes (e.g., such as formaldehyde, acetaldehyde, crotonaldehyde and benzaldehyde) with substances containing amine or amide groups (e.g., urea, melamine and benzoguanamine). Suitable amine cross-linking resins include, for example, benzoguanamine-formaldehyde-based resins, melamine-formaldehyde-based resins (e.g., hexamethoxymethyl-melamine), etherified melamine-formaldehyde, urea-formaldehyde-based resins, and mixtures thereof.

[0087] Condensation products of other amines and amides can also be used, such as, for example, aldehyde condensates of triazines, diazines, triazoles, guanidines, guanamines and alkyl substituted melamines and aryl-substituted melamines. Some examples of such compounds are N, N'-dimethylurea, benzylurea, dicyandiamide, formoguanamine, acetoguanamine, glycoluril, ammeline 2-chloro-4,6-diamino-1,3,5triazine, 6-methyl-2,4-diamino-1 3,5-triazine, 3,5-diaminotriazole, triamaminopyrimidine, 2mercapto-4,6-diaminopyrimidine, 3,4,6-tris (ethylamino) -1,3,5-triazine, and the like. Although the aldehyde used is usually formaldehyde, other similar condensation products can be produced from other aldehydes, such as acetaldehyde, crotonaldehyde, acrolein, benzaldehyde, furfural, glyoxal and the like, and mixtures thereof.

Suitable commercially available amine crosslinking resins include, for example, CYMEL 301, CYMEL 303, CYMEL 370, CYMEL 373, CYMEL 1125, CYMEL 1131, CYMEL 5010 and MAPRENAL MF 980 (all available from Cytec Industries Inc., West Patterson, New Jersey) and URAMEX BF 892 (available from DSM, the Netherlands).

[0089] Non-limiting examples of blocked isocyanate crosslinkers include aliphatic and / or cycloaliphatic blocked polyisocyanates such as HDI (hexamethylene diisocyanate), IPDI (isophorone diisocyanate), TMXDI (bis [4-isocyanatocyclohexyl] methane), H12MDI (tetramethylene malxylene diisocyanate), TMI (isopropenyl-dimethyl-benzyl isocyanate) and their dimers or trimers.

Suitable blocking agents include, for example, n-butanone oxime, ε-caprolactam, diethyl malonate and secondary amines. Non-limiting examples of suitable commercially available blocked isocyanate crosslinkers include VESTANAT B 1358 A, VESTANAT EP B 1186 A, VESTANA EP B 1299 SV (all available from Degussa Corp., Marl, Germany); and DESMODUR VPLS 2078 and DESMODURBL 3175 (available from Bayer AG, Leverkusen, Germany). In some embodiments, blocked isocyanates that have a Mn of at least about 300, more preferably at least about 650, and even more preferably at least about 1000, can be used.

[0090] Some conventional polyester coatings are crosslinked using reactive diluents, such as, for example, styrene. Preferred coating compositions of the invention are free, or at least substantially free, from such reactive cross-linking diluents that may be unsuitable in food contact applications. Preferred cross-linking agents have a Mn of at least about 500.

[0091] One of the preferred optional components is a catalyst for increasing curing speed and / or crosslinking range. Non-limiting examples of catalysts include, but are not limited to, strong acids (e.g., dodecylbenzenesulfonic acid (DDBSA), available as CYCAT 600 from Cytec, methanesulfonic acid (MSA), p-toluenesulfonic acid (pTSA), dinonylnaphthalene disulfonic acid (DNNDSA) and trifluoromethanesulfonic acid ), quaternary ammonium compounds, phosphorus compounds, tin and zinc compounds, and combinations thereof. Specific examples include, but are not limited to, tetraalkylammonium halide, iodide or tetraalkyl or tetraaryl phosphonium acetate, tin octoate, zinc octoate, triphenylphosphine, and similar catalysts known to those skilled in the art. The catalyst, if used, is preferably present in an amount of at least 0.01 wt%, and more preferably at least 0.1 wt.%, based on the weight of the non-volatile material in the coating composition. The catalyst, if used, is preferably present in an amount of no more than 3 wt%, and more preferably no more than 1 wt%, based on the weight of the non-volatile material in the coating composition.

[0092] In some embodiments, the UC functionalized polymer of the invention may be self-crosslinked during curing under suitable coating curing conditions. An effective amount of one or more metallic dryers (with or without a crosslinking agent) can be included in the coating composition to facilitate the formation of crosslinks between the UC groups. Non-limiting examples of suitable metal dryers include aluminum (Al), antimony (Sb), barium (Ba), bismuth (Bi), calcium (Ca), cerium (Ce), chromium (Cr), cobalt (Co), copper (Cu) , iridium (Ir), iron (Fe), lead (Pb), lanthanum (La), lithium (Li), manganese (Mn), neodymium (Nd), nickel (Ni), rhodium (Rh), ruthenium (Ru) , palladium (Pd), potassium (K), osmium (Os), platinum (Pt), sodium (Na), strontium (Sr), tin (Sn), titanium (Ti), vanadium (V), yttrium (Y) , zinc (Zn), zirconium (Zr),

[0093] If desired, the coating compositions of the invention may optionally contain other additives that do not adversely affect the coating composition or the cured coating formed therefrom. Optional additives are preferably at least substantially free of mobile and / or bound BPA and aromatic glycidyl ether compounds (e.g., BADGE, BFDGE and novolac epoxy compounds), and more preferably are completely free of such compounds. Suitable additives include, for example, those that improve the processability or production capacity of the composition, improve the aesthetics of the composition, or improve certain functional properties or characteristics of the coating composition or cured composition derived therefrom, such as adhesion to the substrate. Additives that can be included are carriers, additional polymers, emulsifiers, pigments, metal powders or pastes, fillers, anti-migration agents, antimicrobial agents, extenders, hardeners, lubricants, coalescents, wetting agents, biocides, plasticizers, cross-linking agents, anti-foaming agents, dyes, waxes, antioxidants, anti-corrosion agents, preparations for use flow control, thixotropic agents, dispersing agents, adhesion promoters, UV stabilizers, scavengers, or combinations thereof. Each optional ingredient may be contained in a sufficient amount to serve in accordance with its intended use, but preferably not in an amount such as to have an adverse effect on the coating composition or the cured coating resulting therefrom. hardening agents, lubricants, coalescents, wetting agents, biocides, plasticizers, crosslinking agents, anti-foaming agents, dyes, waxes, antioxidants, anti-corrosion agents, flow control agents, thixotropic agents, dispersing agents, adhesion promoters, UV stabilizers, scavengers or their combinations. Each optional ingredient may be contained in a sufficient amount to serve in accordance with its intended use, but preferably not in an amount such as to have an adverse effect on the coating composition or the cured coating resulting therefrom. hardening agents, lubricants, coalescents, wetting agents, biocides, plasticizers, crosslinking agents, anti-foaming agents, dyes, waxes, antioxidants, anti-corrosion agents, flow control agents, thixotropic agents, dispersing agents, adhesion promoters, UV stabilizers, scavengers or their combinations. Each optional ingredient may be contained in a sufficient amount to serve in accordance with its intended use, but preferably not in an amount such as to have an adverse effect on the coating composition or the cured coating resulting therefrom. thixotropic agents, dispersing agents, adhesion promoters, UV stabilizers, scavengers, or combinations thereof. Each optional ingredient may be contained in a sufficient amount to serve in accordance with its intended use, but preferably not in an amount such as to have an adverse effect on the coating composition or the cured coating resulting therefrom. thixotropic agents, dispersing agents, adhesion promoters, UV stabilizers, scavengers, or combinations thereof. Each optional ingredient may be contained in a sufficient amount to serve in accordance with its intended use, but preferably not in an amount such as to have an adverse effect on the coating composition or the cured coating resulting therefrom.

[0094] Any suitable carrier for the preparation of a coating composition according to the invention may be used. Suitable carriers include liquid carriers such as organic solvents, water, and mixtures thereof. Preferably, the liquid carrier (s) are selected to provide a dispersion or solution of the functionalized UC polymer according to the invention for further development. Suitable organic solvents include aliphatic hydrocarbons (e.g., white spirit, purified kerosene, naphtha with high flash point VM &amp; P, and the like); aromatic hydrocarbons (e.g., benzene, toluene, xylene, solvent petroleum 100, 150, 200 and the like); alcohols (e.g., ethyl alcohol, n-propanol, isopropanol, n-butanol, isobutanol and the like); ketones (e.g., acetone, 2-butanone, cyclohexanone, methylaryl ketones, ethylaryl ketones, methylisoamyl ketones and the like); esters (e.g., ethyl acetate, butyl acetate and the like); glycols (e.g., butyl glycol); glycol ethers (e.g., ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, methoxypropanol and the like); glycol esters (e.g., butyl glycol acetate, methoxypropyl acetate and the like); and mixtures thereof.

[0095] The amount of liquid carrier, if present, contained in the coating composition will vary depending, for example, on the application method and the desired amount of solids. Preferred embodiments of the coating compositions contain at least 30 wt. a liquid carrier, more typically at least 45 wt%. liquid carrier. In such embodiments, the coating composition will typically contain less than 85 wt.%. a liquid carrier, more typically less than 80 wt.% liquid carrier.

[0096] In some embodiments, the coating composition is a solvent based coating composition that preferably contains no more than a de minimis amount (e.g., 0 to 2 wt%) of water. In other embodiments, the coating composition may contain substantial amounts of water.

[0097] In some embodiments, the coating compositions of the invention are a water-based varnish. As already mentioned, the UC functionalized polymer according to the invention may contain water dispersible groups, such as salt residues. In some embodiments, preferably at least about 50 wt. The liquid carrier system is water, more preferably at least 60 wt.%. is water, and even more preferably at least 75% by weight. is water. Some coating compositions of the invention contain at least about 10 wt. % water, more preferably at least about 20 wt.%. water, more preferably at least about 40 wt.%. water (in some embodiments about 50 wt.% or more of water), based on the total weight of the coating composition.

[0098] The coating composition according to the invention can be obtained by means of conventional methods in various ways. For example, coating compositions can be obtained simply by mixing a functionalized polymer, a crosslinking agent, and any other optional ingredients, in any desired order, with sufficient mixing. The resulting mixture may be admixed until all components of the composition are substantially homogeneously mixed. Alternatively, the coating compositions can be obtained as a liquid solution or dispersion by admixing an optional liquid carrier, a UC functionalized polymer, a crosslinking agent, and any other optional ingredients, in any desired order, with sufficient mixing.

[0099] The total solids content of the coating composition according to the invention can vary depending on various factors including, for example, the desired application method. The presently preferred coating compositions contain at least about 30, more preferably at least about 35, and even more preferably at least about 40% by weight. solids based on the total weight of the coating composition. In certain preferred embodiments, the coating composition comprises less than about 80, more preferably less than about 70, and even more preferably less than about 65 wt.%. solids based on the total weight of the coating composition. The solids contents of the coating composition may be outside of the above ranges for certain types of applications. E.g, in the case of coating compositions in the form of internal sprays,% wt. solids can only be about 20 wt.%.

[0100] The cured coatings according to the invention preferably adhere well to metal (e.g. steel, tin-free steel (TFS), tinplate, electrolytic tin plate (ETP), aluminum, etc.) and provide a high level of corrosion resistance or degradation, which may be caused by prolonged exposure to products such as food or drinks. The coatings may be applied to any suitable surface, including the inner surfaces of the containers, the outer surfaces of the containers, the ends of the container, and combinations thereof.

[0101] The coating composition according to the invention may be applied to the substrate by any suitable procedure such as spray coating, roll coating, coil coating, flow coating, curtain coating, bathing coatings, meniscus coatings, kiss coatings, blade coatings, knife coatings, dipping coatings, slit coatings (slot coatings) coating), slide coating, and the like, as well as other types of pre-coating. In one embodiment, where a coating is used to cover the metal sheets or coils, the coating may be applied by rolling through the rolling.

[0102] The coating composition may be applied to the substrate before or after the substrate is made in the article. In some embodiments, at least a portion of the flat substrate is coated with one or more layers of the coating composition of the invention, which is then cured before the substrate is formed in the article (e.g., by stamping, drawing) or embossing (draw-redraw)).

[0103] After application of the coating composition to the substrate, the composition may be cured using various processes, including, for example, firing using conventional or convective methods. Curing can be carried out in separate or combined steps. For example, the coated substrate may be dried at ambient temperature to leave the coating composition in a substantially non-crosslinked state. The coated substrate can then be heated to fully cure the coating composition. In some cases, the coating composition can be dried and cured in one step. In preferred embodiments, the coating composition of the invention is a heat-curing coating composition.

[0104] The curing process may be carried out at any suitable temperature, including, for example, temperatures ranging from about 180 ° C to about 250 ° C. If the coating substrate is a metal coil sheet, the curing of the applied coating composition can be performed, for example, by subjecting the coated metal to an elevated temperature environment of about 210 ° C to about 232 ° C for a suitable period of time (e.g., about 15 to 30 seconds). . If the coating substrate is a metal thin sheet (e.g. as used for the manufacture of three-piece food cans),

[0105] The coating compositions of the invention may be useful in various coating applications. As previously mentioned, the coating compositions are particularly useful as adhesion coatings on the surfaces of internal or external metal packaging containers. Non-limiting examples of such articles include closures (including e.g. inner surfaces of twist-off caps for food and beverage containers); internal crowns; two- and three-part cans (including, for example, containers for food and drinks); shallowly drawn cans; deep drawn cans (including, for example, cans for multi-stage pressed and pressed foods); end of cans (including, for example, easily openable can ends); monoblock aerosol containers; and general industrial containers, cans and end cans.

[0106] Preferred coating compositions according to the invention are particularly suitable for use on internal and external surfaces of metal containers for food and beverages, including food contact coatings. Preferably, the cured coatings are sterilizable when used for food and beverage containers. Preferred cured coatings of the invention are capable of withstanding elevated temperatures often associated with retort processes or other processes for preserving or sterilizing foods or beverages. Particularly preferred cured coatings show improved resistance to such conditions when in contact with food or beverages that exhibit one or more aggressive (or corrosive) chemical properties under such conditions.

[0107] The coating composition according to the invention is particularly suitable for use as a coating on the inner surface of the lateral wall of the three-piece food can. The coating composition is typically applied to a sheet of metal, which is then typically cured before forming the coated side wall of a three-piece food can.

[0108] Some additional non-limiting embodiments of the invention are set forth below.

A. A composition comprising: a polymer (i) having a backbone UC group with a carbon-carbon double bond located between the ring atoms, and (ii) having an iodine value of at least about 10, more preferably at least about 20, more preferably at least about 35 optimally at least about 50; and optionally a crosslinking agent.

B. The article comprising: a metal substrate having the composition of Embodiment A applied to at least a portion of the major surface of the metal substrate.

C. The method comprising: providing a composition according to Embodiment A, and applying the composition to at least a portion of the metal substrate.

D. Any one of Embodiments AC wherein one or more UC groups are at least about 5 wt.%. %, more preferably at least about 15 wt.%, more preferably at least about 30 wt.%, based on the total weight of the UC functionalized monomers contained in the polymer relative to the total weight of the polymer.

E. Any one of Embodiments AD, wherein the UC group contains an unsaturated group that is at least bicyclic (e.g., bicyclic, tricyclic, or a higher order polycyclic group), and more preferably bicyclic.

F. A composition, article or method according to Embodiment E wherein the bicyclic group contains the structure represented by the nomenclature with the expression bicyclo [xyz] alkene, in which: x is 2 or more, and each of y and z is at least 1.

G. A composition, article or method according to Embodiment E wherein the unsaturated bicyclic group includes bicyclo [2.1.1] hexene, bicyclo [2.2.1] hepten, bicyclo [2.2.1] heptadien, bicyclo [2.2.2] octene, bicyclo [2.2.2] octadiene, or mixtures thereof.

H. Any one of Embodiments AG wherein the UC group is provided by 5-norbornene-2,3-dicarboxylic acid, 5-norbornene-2,3-dicarboxylic acid anhydride or mixtures thereof.

I. Any one of Embodiments AE wherein the UC group contains an unsaturated group on a tensioned ring.

J. Any of Embodiments AI wherein the UC group has at least one allylic hydrogen atom.

K. Any one of Embodiments AJ wherein the polymer has a polymer backbone that includes at least one heteroatom, and more preferably the backbone comprises a skeleton formed by step or condensation polymerization.

L. Any of the AK Embodiments, wherein the polymer backbone includes a polyester backbone, a polyether backbone, a polyurethane backbone, or a copolymer backbone thereof (e.g., a polyester-urethane backbone, a polyester-ether backbone, etc.).

M. Any of Embodiments AL wherein the crosslinking agent includes an amine crosslinking agent, an anhydride-based crosslinking agent, a blocked isocyanate blocking agent, a phenolic crosslinking agent, an epoxide functional crosslinker, or mixtures thereof.

N. Any of Embodiments AM, wherein the composition comprises at least 5 wt%, more preferably at least 10 wt%, and even more preferably at least 15 wt%, based on the total solids content of the crosslinking agent.

O. Any of the AN embodiments wherein the composition comprises at least 50 wt. a binder polymer, and more preferably at least 60 wt%. or at least 70% by weight

P. Any of the Embodiments AO, wherein the crosslinking agent comprises a phenol resonating crosslinker.

Q. Any of the AP Embodiments, wherein the composition further comprises a liquid carrier.

RR. Any of Embodiments AQ wherein the composition comprises a cured coating composition, more preferably a cross-linked coating composition.

S. A composition, article or method according to Embodiment R wherein the crosslinking agent comprises a cross linking phenolic resole that is covalently attached to the polymer via a linkage formed by the reaction of the UC group and the phenolic crosslinking agent.

T. Any of the BS Embodiments, wherein the metal substrate comprises a metal substrate of the food or beverage can or portion thereof.

U. A of any of the embodiments of AT wherein the polymer comprises a water-dispersible polymer, more preferably a water-dispersible polymer having sufficient salt moieties to form a stable aqueous solution or dispersion.

V. Any one of Embodiments AT wherein the composition comprises a solvent based composition.

W. Any of Embodiments AV, wherein the polymer comprises a polyester binder polymer (preferably present in the coating composition based on a total coating solids content of 50-95% by weight) and the crosslinking agent includes a phenol crosslinking agent, more preferably a crosslinking phenol resole.

TEST METHODS [0109] Unless otherwise indicated, the following test methods were used in the Examples that follow.

A. Solvent Resistance Test [0110] The range of "curing" or curing the coating is measured as solvent resistance, such as methyl ethyl ketone (MEK) or isopropyl alcohol (IPA). This test is carried out in accordance with ASTM D5402-93. The number of double rubs (that is one move back and forth) was reported. Preferably, the resistance to the MEK solvent is at least 30 double rubs.

B. Adhesion Test [0111] An adhesion study was conducted to assess whether the coating compositions adhere to the coated substrate. The adhesion test was carried out in accordance with ASTM D3359 Test Method B, using SCOTCH 610 tape, available from the 3M Company of Saint Paul, Minnesota. The adhesion is generally graded on a scale of 0 to 10, where the rating of "10" means no abnormality in adhesion, rating "9" means that 90% of the coating still adheres, rating "8" means that 80% of the coating continues it adheres, and so on. It is considered here that the coating meets the Adhesion Test if it has a grip rating of at least 8.

C. Test for resistance to turbidity [0112] Resistance to cloudiness measures the ability of the coating to withstand the action of various solvents. Typically, cloudiness is measured by the amount of water absorbed by the coated film. When the film absorbs water, it generally becomes cloudy or has a white appearance. The haze was visually measured using a scale of 0-10, where rating "10" means no turbidity, rating "5" means slight whitening of the film, and rating "0" means serious whitening of the film.

D. Water Pasteurisation (also referred to as retortation in water) [0113] Retorting in water is a measurement of the integrity of a coated substrate after exposure to heat and pressure in a liquid, such as water. Performing water retorting is not necessarily required for all food and beverage coatings, but is desirable for some types of products that are packaged under retort conditions. The test is carried out by subjecting the substrate to a heat treatment ranging from 105-130 ° C and pressure of 15 psi (~ 1.05 kg / cm²) for a period of 15 to 90 minutes. The coated substrate was then tested for adhesion and opacity as described above.

E. Iodine Number Prepare a starch solution by dissolving 5 g of soluble starch in 100 milliliters (ml) of deionized water (DI). Add 400 ml of boiling DI water, stir until clarity and leave to cool. This solution will not be stored for more than a few days and should be fresh if needed. Prepare a solution of potassium iodide by dissolving 150 g of potassium iodide in 1000 ml DI water

[0115] A small part of the test sample should be weighed by the difference in the Erlenmeyer flask to the iodine number, the amount of sample taken is such that from 10 to 30% iodine solution (Wijsa monochloride iodine solution - Fisher Scientific Co. Cat. No. SI106-4) will be absorbed. Pipette 20 ml of chloroform into each sample flask. Stop the flasks, add the Teflon stir bar and mix until the samples are dissolved. Prepare two flasks for zero tests by pipetting 20 ml of chloroform into separate flasks. Pipette into each flask (2 flasks for each sample and 2 flasks for zero tests) 25 ml of iodine solution.

[0116] Stop the flasks, mix for 30 seconds and then leave standing stirring by centrifugation from time to time for 30 minutes in a dark place at room temperature. At the end of the withdrawal time, pipette 20 ml. potassium iodide solution and 80 ml DI water, close with a stopper and mix. Add 2 ml of the starch solution and titrate immediately with 0,1 N sodium thiosulfate (Fisher Scientific Cat. No. SS368-1).

[0117] Calculate the iodine value as the difference in the average volume (in milliliters) of 0.1 N sodium thiosulphate required in the zero test minus the average volume (in milliliters) required for the sample, multiplied by 1.269 and divided by the sample mass in grams.

[0118] The iodine value value is calculated by the following equation: [(Average volume for the zero test - Average volume for the sample) x 1.269] / [Sample weight in grams]. The iodine number is given as iodine centigrams absorbed by 1 gram of material.

[0119] The iodine value values ​​given in the Example Section were determined by this methodology.

EXAMPLES [0120] The invention is illustrated in the following examples. It should be understood that specific examples, materials, quantities and procedures must be interpreted broadly in accordance with the scope and spirit of inventions defined herein. Unless otherwise indicated, all parts and percentages are by weight and all molecular weights are by weight average molecular weight. Unless otherwise specified, all chemicals used are commercially available, e.g. from Sigma-Aldrich, St. Louis, Missouri.

Example 1: Functionalised polyesters of UC

Series 1: A polyester comprising 5-norbomenzo-2,3-dicarboxylic anhydride. Cyclohexane-1,4-dimethanol (124.1 g of a 90% solution in water), 2-methyl-1,3-propanediol (64.6 g) ), terephthalic acid (42.3 g), isophthalic acid (84.4 g) and dibutyltin oxide (0.40 g) were placed in a 1 liter, round bottomed flask equipped with a mechanical stirrer, thermocouple, packed column ( topped with a Dean-Stark cap and cooler) and a stopper for future restorations. The contents of the flask were heated slowly (so that the distillate temperature did not exceed 100 ° C) to 230 ° C and held until the acid number dropped to 0.4 mg KOH / g resin. The temperature was then reduced to 180 ° C, and cyclohexane-1,4-dicarboxylic acid (63.3 g) and 5-norbornene-2,3-dicarboxylic anhydride (50.2 g) were added to the flask. The temperature was raised to 220 ° C and maintained until the resin cleared. The temperature was lowered to 180 ° C, xylene (19.5 g) was added to the flask, the packed column was removed, and the cap was pre-filled with xylene in preparation for azeotropic reflux. The temperature was again raised to 220 ° C (or this limited by the reflux) and maintained until the acid number fell below 5 mg KOH / g resin. At this point, the resin was cooled to 170 ° C and adjusted to 50% solids with AROMATIC 150 (166.8 g) and cyclohexanone (166.8 g). After unification, the resin was fully cooled and discharged. and the cap was pre-filled with xylene in preparation for azeotropic reflux. The temperature was again raised to 220 ° C (or this limited by the reflux) and maintained until the acid number fell below 5 mg KOH / g resin. At this point, the resin was cooled to 170 ° C and adjusted to 50% solids with AROMATIC 150 (166.8 g) and cyclohexanone (166.8 g). After unification, the resin was fully cooled and discharged. and the cap was pre-filled with xylene in preparation for azeotropic reflux. The temperature was again raised to 220 ° C (or this limited by the reflux) and maintained until the acid number fell below 5 mg KOH / g resin. At this point, the resin was cooled to 170 ° C and adjusted to 50% solids with AROMATIC 150 (166.8 g) and cyclohexanone (166.8 g). After unification, the resin was fully cooled and discharged.

Series 1: Polyester containing 5-norbornene-2,3-dicarboxylic anhydride and pyromellitic dianhydride (PMDA) [0122] Cyclohexane-1,4-dimethanol (626.2 g of a 90% solution in water), 2-methyl-1 , 3-propanediol (325.8 g), terephthalic acid (158.1 g), isophthalic acid (315.8 g) and dibutyltin oxide (1.9 g) were placed in a 5-L, 4-necked round bottom flask equipped with a mechanical stirrer , a thermocouple, a packed column (topped with a Dean-Stark trap and a condenser) and a stopper for future restorations. The contents of the flask were heated slowly (so that the distillate temperature did not exceed 100 ° C) to 232 ° C under a nitrogen atmosphere and held until the acid number dropped to 1.0 mg KOH / g resin. The temperature was then reduced to 170 ° C and 5-norbornene-2,3-dicarboxylic anhydride (585.0 g) was added to the flask. After 1 hour holding at 170 ° C, xylene (154.9 g) was added to the flask, the packed column was removed and the cap pre-filled with xylene in preparation for azeotropic reflux. The temperature was again raised to 220 ° C (or this limited by reflux) and maintained until the acid number fell below 2 mg KOH / g resin. At this point, the resin was cooled to 170 ° C and brought to 60% solids using cyclohexanone (1032.5 g). The resulting resin was mixed until uniform and 2697.0 grams were transferred to a 5-liter flask equipped with a mechanical stirrer, thermocouple, condenser and stopper for sampling or supplementation. A pyromellitic acid dianhydride (86.9 g) was added to the flask and the contents were heated to 120 ° C under a nitrogen atmosphere. After 4 hours at 120 ° C, cyclohexanone (222.0 g) and solvent AROMATIC 150 (1149.0 g) were added to give a solution containing 41% solids, and the resin was cooled to room temperature. The resin obtained had an acid number of 30.2 mg KOH / g resin and a hydroxyl number 26.4 mg KOH / g resin.

After 1 hour holding at 170 ° C, xylene (254.0 g) was added to the flask, the packed column was removed, and the cap was pre-filled with xylene in preparation for azeotropic reflux. The temperature was again raised to 220 ° C (or this limited by reflux) and maintained until the acid number fell below 2 mg KOH / g resin. At this point the resin was cooled to 170 ° C and brought to 81% solids by means of cyclohexanone (659.0 g). The resulting resin was mixed until uniform and transferred 2175.0 grams to a 5-liter flask equipped with a mechanical stirrer, thermocouple, condenser and stopper for taking samples or additions. A pyromellitic acid dianhydride (117.6 g) was added to the flask and the contents were heated to 120 ° C under a nitrogen atmosphere. After 4 hours at 120 ° C, butanol (405.0 g) and 2-butoxyethan-1-ol (butyl cellosolve) (405.0 g) were added to obtain a solution containing 58% solids, and the resin cooled to room temperature. The resin obtained had an acid number of 23.6 mg KOH / g resin. 384.9 g of the resulting solution was combined with dimethyl ethanolamine (6.7 g) and heated to 60 ° C in a 1 L round bottomed flask with mechanical stirring. DI water (248.4 g) was added to the flask over 30 minutes (resulting in 35% solids) while the temperature of this batch was allowed to drop to room temperature. 9 g of the resulting solution was combined with dimethyl ethanolamine (6.7 g) and heated to 60 ° C in a 1 liter round bottom flask with mechanical stirring. DI water (248.4 g) was added to the flask over 30 minutes (resulting in 35% solids) while the temperature of this batch was allowed to drop to room temperature. 9 g of the resulting solution was combined with dimethyl ethanolamine (6.7 g) and heated to 60 ° C in a 1 liter round bottom flask with mechanical stirring. DI water (248.4 g) was added to the flask over 30 minutes (resulting in 35% solids) while the temperature of this batch was allowed to drop to room temperature.

Example 2: Coating compositions

Series 1:

[0124] A solvent-based coating composition was obtained that contained, based on the total solids content in the coating, 75 wt. the polyester resin of Example 1, Series 1 and 25 wt. a GPRI resolving phenol

7590 (Georgia-Pacific). The coating composition contained about 40 wt. solid substances.

Series 2:

[0125] A solvent-based coating composition was obtained that contained, based on the total solids content in the coating, 75 wt .-%. the polyester resin of Example 1, Series 2 and 25 wt. a cross-linking phenolic radical GPRI 7590 (Georgia-Pacific). The coating composition contained about 40 wt. solid substances.

Comparative Series 3 [0126] As a control, a commercially available epoxy based, solvent based coating composition comprising a phenolic crosslinking agent is provided.

Example 3: Cured coating compositions [0127] The coating compositions of Example 2 were applied to a metal substrate and cured to form cured coatings. The coating performance test results for cured coatings are shown in Tables 1 and 2 below.

Table 1: Retorting and manufacturing properties

<td>Coating composition</td><td>Example 2, Comparative Series 3</td><td>Example 2, Series 1</td><td>Example 2, Series 2</td>

<td>Adhesion</td><td>10</td><td>10</td><td>10</td>

<td>Resistance to MEK (double abrasion)</td><td>35</td><td>&gt; 100</td><td>&gt; 100</td>

<td>Retorting in water¹</td><td></td><td></td><td></td>

<td>Turbidity (C / G)</td><td>10/10</td><td>10/10</td><td>10/10</td>

<td>Adhesion (C / G)</td><td>10/10</td><td>10/10</td><td>10/10</td>

<td>The end of sanitary can o</td><td></td><td></td><td></td>

<td>Coating composition</td><td>Example 2, Comparative Series 3</td><td>Example 2, Series 1</td><td>Example 2, Series 2</td>

<td>size 202</td><td></td><td></td><td></td>

<td>Cracks</td><td>Lack</td><td>Lack</td><td>Lack</td>

<td>Metal exposure (mili-Amp) ²</td><td>6.4</td><td>2.8</td><td>7.4</td>

<td>3 Corrosion CuSO₄</td><td>Lack</td><td>Lack</td><td>Lack</td>

<td>The end of sanitary box size 206</td><td></td><td></td><td></td>

<td>Cracks</td><td>Lack</td><td>Lack</td><td>Lack</td>

<td>Metal exposure (mA) ²</td><td>11.2</td><td>6.2</td><td>13.5</td>

<td>3 Corrosion CuSO₄</td><td>Lack</td><td>Lack</td><td>Lack</td>

<td colspan="4">Firing: 10 minutes at 400 ° F (204 ° C) maximum metal temperature (PMT) in a gas-fired furnace with forced draft Substrate 0.25 75 # -ETP Weight coating: 4.5-5.0 msi (milligrams per square inch); equivalent in meters is 7.8 grams per square meter Grading scale: 0 - 10: 10 = No irregularities¹60 minutes at 250 ° F (121 ° C) and 15 psi (~ 1.05 kg / cm²) in distilled water, according to Test Method D; C / G = liquid / gas phase²Electrolyte - 1% NaCl; Average of 4 endings³Endings immersed for 10 minutes in a CuSO4 / HCl solution.</td>

Table 2: Corrosion resistance

<td></td><td colspan="3">ETP</td><td colspan="3">TFS</td>

<td></td><td>Example 2, Comparative Series 3</td><td>Example 2, Series 1</td><td>Example 2, Series 2</td><td>Example 2, Comparative Series 3</td><td>Example 2, Series 1</td><td>Example 2, Series 2</td>

<td>2% salt / 3% acetic acid solution</td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>Adhesion /</td><td>10/10</td><td>10/9</td><td>9/10</td><td>8/5</td><td>8/8</td><td>8/7</td>

<td></td><td colspan="3">ETP</td><td colspan="3">TFS</td>

<td></td><td>Example 2, Comparative Series 3</td><td>Example 2, Series 1</td><td>Example 2, Series 2</td><td>Example 2, Comparative Series 3</td><td>Example 2, Series 1</td><td>Example 2, Series 2</td>

<td>turbidity</td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>Corrosion</td><td>9</td><td>9</td><td>9</td><td>4</td><td>5</td><td>6</td>

<td>1% solution acid lactic</td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>Adhesion / turbidity</td><td>9/8</td><td>9/10</td><td>9/10</td><td>7/4</td><td>8/9</td><td>7/10</td>

<td>Corrosion</td><td>8</td><td>8</td><td>9</td><td>4</td><td>5</td><td>7</td>

<td>2% saline solution</td><td></td><td></td><td></td><td></td><td></td><td></td>

<td>Adhesion / turbidity</td><td>5/10</td><td>10/10</td><td>5/7</td><td>6/10</td><td>9/10</td><td>4/8</td>

<td>Corrosion</td><td>9</td><td>10</td><td>9</td><td>9</td><td>10</td><td>9</td>

<td colspan="7">Tests were carried out using 202 size sanitary can ends; The ends were immersed in the specified solution and retorted for 60 minutes at 250 ° F (121 ° C) and 15 psi (~ 1.05 kg / cm²). Firing: 10 minutes at 400 ° F (204 ° C) PMT in a gas-fired furnace with forced thrust Substrate: 0.25 75 # ETP and 75 # TFS Weight coating: 4.5 - 5.0 msi (milligrams per square inch); equivalent in meters is 7.8 grams per square meter The scale of grades: 0 - 10; 10 = no irregularities</td>

Example 4: UC functionalized polyurethane Cyclohexane-dimethanol (1449,7 g 90% solution in water), MP-diol (i.e., 5-methylpropanediol) (722.5 g), terephthalic acid (293.3 g), acid isophthalic acid (578 g), maleic anhydride (808.4 g), dibutyltin oxide (4.2 g) (product FASTCAT 4201) and xylene (187 g) were added to a glass reaction flask equipped with stirrer, nitrogen inlet and reflux condenser. The radiator was additionally equipped with a Dean-Stark flask to capture and quantify the water released during the reaction. The reactor was set to 230 ° C. After approximately 5 hours, the acid value of the resulting polyester polymer was about 0.5 mg KOH / g resin. The reactor temperature was reduced to about 160 ° C, at which point dicyclopentadiene ("DCPD") (549.4 g) was added. The reactor was maintained at 160 ° C for an additional 6 hours until the Diels-Alder reaction was completed between maleate unsaturation and DCPD. It is believed that the resulting structure resembles that of a material obtained from 5-norbornene-2,3-dicarboxylic anhydride. The resulting modified polyester polymer composition contained 84% solids and had an acid number of 1.4 mg KOH / g resin and an OH number of 56.6 mg KOH / g resin.

[0129] A modified polyester composition (1044.3 g) was added to a new reaction flask (of the same configuration as described above) together with diisocyanate isophorone ("IPDI") (247.3 g) and dimethylol propionic acid (74.6 g). ). The temperature of the flask was kept at about 100 ° C, and the reaction was continued for about 6 hours, at which point butanol (307 g), 2-butoxyethan-1-ol (307 g) and cyclohexanone (1587 g) were added to the flask. The resulting polyester-urethane polymer composition contained 24% solids and had an acid number of 26.5 mg KOH / g resin.

Example 5: Coating composition [0130] The polyester-urethane polymer composition of Example 4 (100g) was combined with a phenol resole messenger resin (7.5g). The ratio of the resulting coating formulation is 80% by weight of the polyester-urethane polymer and 20% of the phenolic resin.

Example 6: Cured coating composition [0131] A sample of the coating composition of Example 5 was applied to both commercially available ETP and steel-free TFS using a wound wire. The coated steel samples were fired for about 12 minutes in a 402 ° F oven (204 ° C) to dry and cure the coating. After drying and curing, it was found that the coating film weight is from about 4.5 to 5.0 mg coating per square inch of coated substrate (equivalent in meters is 7-7.8 grams per square meter). It was noticed that the coating looked smooth and shiny and had a golden hue. Samples of this coated substrate were used in food can ends and the coating composition of Example 5 was oriented as an inner coating. Also, an analogous set of control can ends for foodstuffs was made of tin-plated and tin-free steel coated with a conventional epoxy-based coating system, which is now commercially used as a coating with high corrosion resistance to the interior of food cans and ends. Samples of both control and experimental terminations were then subjected to a variety of coating properties investigations to assess the suitability of the coatings for use as a food contact coating for cans for food or beverages. The cured coating composition of Example 6 on an ETP substrate exhibited good coating properties (e.g., comparable adhesion, opacity, stain resistance and corrosion resistance, as with commercially available control).