2. Description of Related Art It is well known that limiting the exposure of oxygen-sensitive products to oxygen maintains and enhances the quality and shelf-life of the product. For instance, by limiting the oxygen exposure of oxygen sensitive food products in a packaging system, the quality of the food product is maintained, and food spoilage is avoided. In addition such packaging also keeps the product in inventory longer, thereby reducing costs incurred from waste and restocking. In the food packaging industry, several means for limiting oxygen exposure have already been developed, including modified atmosphere packaging (MAP), vacuum packaging and oxygen barrier film packaging. In the first two instances, reduced oxygen environments are employed in the packaging, while in the latter instance, oxygen is physically prevented from entering the packaging environment.

Another, more recent, technique for limiting oxygen exposure involves incorporating an oxygen scavenger into the packaging structure. Incorporation of a scavenger in the package can scavenge oxygen present inside the package. The oxygen thus scavenged either can be present in the interior when product is filled into the package, or can migrate into the package after product is filled. In addition, such incorporation can provide a means of intercepting and scavenging oxygen as it passes through the walls of the package (herein referred to as an "active oxygen barrier"), thereby maintaining the lowest possible oxygen level throughout the package.

In many cases, however, the onset of oxygen scavenging in this system may not occur for days or weeks. The delay before the onset of useful oxygen scavenging is hereinafter referred to as the induction period. In addition, the rate of oxygen scavenging can also be relatively low. Much work has been done both to minimize the induction period and increase

the scavenging rate. One common approach that is useful in both areas is the use of cobalt oleate as a catalyst for oxygen scavenging.

However, because the oleate chain has a carbon-carbon double bond, allylic hydrogens (i. e. a hydrogen bound to a carbon bound to one of the carbon atoms forming the double bond) are present and react with oxygen. While such reaction scavenges oxygen, it also fragments the oleate chain. If the cobalt oleate catalyst is present in a layer of an oxygen scavenging packaging layer in direct contact with a packaged product (e. g. a food, a beverage, or a pharmaceutical), oleate fragments may migrate into the packaged product, where they can pose organoleptic problems, by imparting unpleasant taste or odor to a packaged food or beverage.

Other cobalt salts have been considered as catalysts, but their use has demonstrated other shortcomings. Cobalt neodecanoate has a catalytic activity comparable to that of cobalt oleate, but both neodecanoate and fragments thereof are not on the GRAS list. Cobalt stearate does not generate fragments, and stearate is GRAS ; however, the catalytic activity of cobalt stearate is less than that of either cobalt oleate or cobalt neodecanoate.

Therefore, a need exists for new formulations of cobalt salts that have high catalytic activity, are GRAS, and pose minimal or no organoleptic problems.

SUMMARY OF THE INVENTION In one embodiment, the present invention relates to a solid masterbatch composition, comprising cobalt stearate and an oxidizable resin. Typically, the cobalt stearate and the oxidizable resin are compounded together, but they can be formed by powder-or solvent- coating of the cobalt stearate on the resin (the resin typically being provided as pellets).

Preferably, the oxidizable resin is a homo-or copolymer comprising cyclohexenyl methyl acrylate (e. g. ethylene/methyl acrylate/cyclohexenyl methyl acrylate terpolymer (EMCM)).

The oxidizable resin can be blended with an inert carrier resin, such as ethylene/vinyl acetate copolymer (EVA), ethylene/methyl acrylate copolymer (EMAC), ethylene/butyl acrylate copolymer (EBAC), or polyethylene (PE), or mixtures thereof, among others. The composition can also comprise a photoinitiator, an antioxidant, or other useful compounds.

In another embodiment, the present invention is directed to a method of making a masterbatch comprising an oxidizable resin and cobalt stearate, comprising compounding the cobalt stearate with the oxidizable resin. In a related embodiment, the masterbatch can be

further compounded with an inert carrier resin, a photoinitiator, or other compounds. The oxidizable resin and inert carrier resin can be as described above.

In a further embodiment, the present invention relates to a method of making a packaging article, comprising (i) providing a masterbatch comprising cobalt stearate and a first oxidizable resin compounded together; (ii) providing a composition comprising a second oxidizable resin; (iii) combining the masterbatch and the composition, to form a blend; and (iv) forming the blend into the packaging article. The masterbatch can also comprise an inert carrier resin, a photoinitiator, or other useful compounds. The oxidizable resins and inert carrier resins are as described above. The resultant packaging article can be a single layer film, a multilayer film, a single layer rigid packaging article, or a multilayer rigid packaging article, among others, and can comprise materials not present in the blend.

These formulations of cobalt stearate have high catalytic activity, are GRAS, and pose minimal or no organoleptic problems.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS In one embodiment, the present invention relates to a solid masterbatch composition, comprising cobalt stearate and an oxidizable resin. Preferably, the cobalt stearate and the oxidizable resin are compounded together, although other formulations (e. g. powder-or solvent-coating of the cobalt stearate on the resin) are possible.

A transition metal catalyst, such as cobalt stearate, accelerates the rate of oxygen scavenging. Though not to be bound by theory, useful catalysts are believed to include those which can readily interconvert between at least two oxidation states, such as cobalt. See Sheldon, R. A.; Kochi, J. K. ;"Metal-Catalyzed Oxidations of Organic Compounds"Academic Press, New York 1981.

Typically, the amount of cobalt in the masterbatch may range from about 0.01 % to about 5.0 %, preferably from about 0.1 % to about 2.0%, more preferably from about 1.0 % (such as 0.9 % or 1.1%) to about 2.0 %, by weight of the total masterbatch, based on the metal content only (excluding ligands, counterions, etc.). In the event the amount of cobalt stearate is less than 1% (as cobalt stearate), it follows that the oxidizable resin, and any inert carrier resin or additive (as described below), will comprise substantially all of the masterbatch, i. e. more than 99% as indicated below for the oxidizable resin.

The cobalt stearate can be any formulation of cobalt stearate. Some commercially available formulations of cobalt stearate further comprise additives, such as antioxidants, for

example, 9000 ppm Irganox 1076 (n-octadecyl 3- (3, 5-di-t-butyl-4-hydroxyphenyl propionate, Ciba). Preferably, the concentration of antioxidants in the cobalt stearate formulation will be about 1000 ppm or less.

By"oxidizable resin"is meant an oxidizable organic compound that, upon oxidation, substantially does not yield fragments that are capable of migrating out of the masterbatch composition, or an oxygen scavenging layer formulated from the masterbatch composition.

The oxidizable resin is a hydrocarbon with a polymeric backbone. The hydrocarbon can be saturated or unsaturated, and substituted or unsubstituted. Examples of such hydrocarbons include, but are not limited to, diene polymers such as polyisoprene, polybutadiene (especially 1,2-polybutadienes, which are defined as those polybutadienes possessing greater than or equal to 50% 1,2 microstructure), and copolymers thereof, e. g. styrene-butadiene. Such hydrocarbons also include polymeric compounds such as polypentenamer, polyoctenamer, and other polymers prepared by olefin metathesis; diene oligomers such as squalene; and polymers or copolymers derived from dicyclopentadiene, norbornadiene, 5-ethylidene-2-norbornene, or other monomers containing more than one carbon-carbon double bond (conjugated or non-conjugated). These hydrocarbons further include carotenoids such as (3-carotene.

Examples of substituted hydrocarbons include, but are not limited to, those with oxygen-containing moieties, such as esters, carboxylic acids, aldehydes, ethers, ketones, alcohols, peroxides, or hydroperoxides. Specific examples of such hydrocarbons include, but are not limited to, condensation polymers such as polyesters derived from monomers containing carbon-carbon double bonds; unsaturated fatty acids such as oleic, ricinoleic, dehydrated ricinoleic, and linoleic acids and derivatives thereof, e. g. esters. Such hydrocarbons also include polymers or copolymers derived from (meth) allyl (meth) acrylates.

Preferably, the oxidizable resin comprises a polymeric backbone, cyclic olefinic pendant groups, and linking groups linking the backbone with the pendant groups.

More preferably, the polymeric backbone is ethylenic. The polymeric backbone can comprise monomers of ethylene or styrene.

More preferably, the linking groups are selected from: <BR> <BR> <BR> - 0- (CHR) n- ;- (C=0)-0- (CHR),- ;-NH- (CHR) n- ;-0- (C=0)- (CHR).- ;<BR> <BR> <BR> <BR> <BR> <BR> - (C=O)-NH- (CHR) n- ; or- (C=O)-O-CHOH-CH2-0- ; wherein R is hydrogen, methyl, ethyl, propyl, or butyl; and n is an integer from 1 to 12, inclusive.

More preferably, the cyclic olefinic pendant group has the structure (0 :

wherein ql, q2, q3, q4, and r are independently selected from hydrogen, methyl, or ethyl; m is-(CH2) n-, wherein n is an integer from 0 to 4, inclusive; and, when r is hydrogen, at least one of ql, q2, q3, and q4 is also hydrogen.

A most preferred oxidizable resin is ethylene/methyl acrylate/cyclohexenyl methyl acrylate terpolymer (EMCM). EMCM can be readily made following the teachings of copending U. S. patent application 09/127,316, incorporated herein by reference.

The composition may also comprise a mixture of two or more oxidizable resins as described above.

The amount of oxidizable resin may range from about 1 to about 99.99%, preferably from about 10 to about 99%, more preferably from about 20% to about 99%, by weight, of the composition.

Optionally, the oxidizable resin can be blended with an inert carrier resin. By"inert carrier resin"is meant a polymeric organic compound that does not substantially react with oxygen. Examples of inert carrier resins include ethylene/vinyl acetate copolymer (EVA), ethylene/methyl acrylate copolymer (EMAC), ethylene/butyl acrylate copolymer (EBAC), or polyethylene (PE), or mixtures thereof, among others.

Such inert carrier resins are thermoplastic and render the composition more adaptable for processing into a packaging article. Blends of different inert carrier resins may also be used. However, the selection of the inert carrier resin largely depends on the article to be manufactured and the end use thereof. Such selection factors are well known in the art. For instance, the clarity, cleanliness, oxygen scavenging effectiveness, barrier properties, mechanical properties, or texture of the article can be adversely affected by a blend containing an inert carrier resin which is incompatible with the oxidizable resin.

When one or more inert carrier resins are used, those resins can comprise, in total, as much as 99% by weight of the composition. Preferably, the inert carrier resin or resins will comprise at least about 10% by weight of the composition.

The masterbatch composition can also comprise a photoinitiator, an antioxidant, or other compounds useful in oxygen scavenging packaging articles made using the masterbatch.

Suitable photoinitiators are well known to those skilled in the art. Specific examples include, but are not limited to, benzophenone, o-methoxybenzophenone, acetophenone, o- methoxy-acetophenone, acenaphthenequinone, methyl ethyl ketone, valerophenone, hexanophenone, a-phenyl-butyrophenone, p-morpholinopropiophenone, dibenzosuberone, 4- morpholinobenzophenone, benzoin, benzoin methyl ether, 4-o-morpholinodeoxybenzoin, p- diacetylbenzene, 4-aminobenzophenone, 4'-methoxyacetophenone, a-tetralone, 9- acetylphenanthrene, 2-acetylphenanthrene, 10-thioxanthenone, 3-acetylphenanthrene, 3- acetylindole, 9-fluorenone, 1-indanone, 1,3,5-triacetylbenzene, thioxanthen-9-one, xanthene-9- one, 7-H-benz [de] anthracen-7-one, benzoin tetrahydropyranyl ether, 4,4'-bis (dimethylamino)- benzophenone, l'-acetonaphthone, 2'-acetonaphthone, acetonaphthone and 2,3-butanedione, benz [a] anthracene-7,12-dione, 2,2-dimethoxy-2-phenylacetophenone, a, a- diethoxyacetophenone, and a, a-dibutoxyacetophenone, among others. Singlet oxygen generating photosensitizers such as Rose Bengal, methylene blue, and tetraphenyl porphine may also be employed as photoinitiators. Polymeric initiators include poly (ethylene carbon monoxide) and oligo [2-hydroxy-2-methyl-l- [4- (l-methylvinyl) phenyl] propanone].

Use of a photoinitiator is preferable because it generally provides faster and more efficient initiation. However, due to the high cost of photoinitiators (typically-$100/lb), it is desirable to use the minimum amount of photoinitiator required to initiate oxygen scavenging.

This minimum amount will vary depending on the photoinitiator used, the wavelength and intensity of ultraviolet light used to initiate, and other factors. Preferably, the photoinitiator is either on the U. S. Food and Drug Administration GRAS (generally regarded as safe) list, or exhibits substantially no migration from the packaging article to the product (i. e. less than 50 ppb in the product).

Photoinitiators that are especially useful in the present invention include benzophenone derivatives containing at least two benzophenone moieties, as described in copending U. S. patent application 08/857,325, filed May 16,1997. These compounds act as effective photoinitiators to initiate oxygen scavenging activity in oxygen scavenging compositions.

Such benzophenone derivatives have a very low degree of extraction from oxygen scavenging

compositions, which may lead to reduced contamination of a packaged product by extracted photoinitiator.

A"benzophenone moiety"is a substituted or unsubstituted benzophenone group.

Suitable substituents include alkyl, aryl, alkoxy, phenoxy, and alicylic groups contain from 1 to 24 carbon atoms or halides.

The benzophenone derivatives include dimers, trimers, tetramers, and oligomers of benzophenones and substituted benzophenones.

The benzophenone photoinitiators are represented by the formula: Xm (Y) n wherein X is a bridging group selected from sulfur; oxygen; carbonyl ;-SiR2-, wherein each R is individually selected from alkyl groups containing from 1 to 12 carbon atoms, aryl groups containing 6 to 12 carbon atoms, or alkoxy groups containing from 1 to 12 carbon atoms;-NR'-, wherein R'is an alkyl group containing 1 to 12 carbon atoms, an aryl group containing 6 to 12 carbon atoms, or hydrogen; or an organic group containing from 1 to 50 carbon atoms, preferably from 1 to 40 carbon atoms; m is an integer from 0 to 11; Y is a substituted or unsubstituted benzophenone group; and n is an integer from 2 to 12.

X can be a divalent group, or a polyvalent group with 3 or more benzophenone moieties. The organic group, when present, can be linear, branched, cyclic (including fused or separate cyclic groups), or an arylene group (which can be a fused or non-fused polyaryl group). The organic group can contain one or more heteroatoms, such as oxygen, nitrogen, phosphorous, silicon, or sulfur, or combinations thereof. Oxygen can be present as an ether, ketone, ester, or alcohol.

The substituents of Y, herein R", when present, are individually selected from alkyl, aryl, alkoxy, phenoxy, or alicylic groups containing from 1 to 24 carbon atoms, or halides.

Each benzophenone moiety can have from 0 to 9 substituents.

Preferably, the combined molecular weight of the X and R"groups is at least about 30 g/mole. Substituents can be selected to render the photoinitiator more compatible with the masterbatch composition.

Examples of such benzophenone derivatives comprising two or more benzophenone moieties include dibenzoyl biphenyl, substituted dibenzoyl biphenyl, benzoylated terphenyl, substituted benzoylated terphenyl, tribenzoyl triphenylbenzene, substituted tribenzoyl triphenylbenzene, benzoylated styrene oligomer (a mixture of compounds containing from 2 to

12 repeating styrenic groups, comprising dibenzoylated 1, 1-diphenyl ethane, dibenzoylated 1,3-diphenyl propane, dibenzoylated 1-phenyl naphthalene, dibenzoylated styrene dimer, dibenzoylated styrene trimer, and tribenzoylated styrene trimer), and substituted benzoylated styrene oligomer. Tribenzoyl triphenylbenzene and substituted tribenzoyl triphenylbenzene are especially preferred.

When a photoinitiator is used, its primary function is to enhance and facilitate the initiation of oxygen scavenging upon exposure to radiation. The amount of photoinitiator can vary. In many instances, the amount will depend on the oxidizable resin used, the wavelength and intensity of electromagnetic radiation used, the nature and amount of antioxidants used, as well as the type of photoinitiator used. The amount of photoinitiator also depends on how the masterbatch will be used. For instance, if the masterbatch will be formulated into a film layer placed, in a packaging article, underneath a layer which is somewhat opaque to the radiation used for initiation, more photoinitiator may be needed. For most purposes, however, the amount of photoinitiator, when used, will be in the range of 0.01 to 10% by weight of the total composition.

Antioxidants may be used in the masterbatch to control initiation of oxygen scavenging. An antioxidant as defined herein is a material which inhibits oxidative degradation or cross-linking of polymers. Typically, antioxidants are added to facilitate the processing of polymeric materials or prolong their useful lifetime. In relation to this invention, such additives prolong the induction period for oxygen scavenging.

Antioxidants such as 2,6-di (t-butyl)-4-methylphenol (BHT), 2,2'-methylene-bis (6-t- butyl-p-cresol), triphenylphosphite, tris- (nonylphenyl) phosphite, n-octadecyl 3- (3, 5-di-t-butyl- 4-hydroxyphenyl propionate (Irganox 1076, Ciba) and dilaurylthiodipropionate are suitable for use with this invention.

The amount of antioxidant may also have an effect on oxygen scavenging. As mentioned earlier, such materials are usually present in oxidizable organic compounds or structural polymers to prevent oxidation or gelation of the polymers. Typically, they are present in a finished product made from the masterbatch at about 0.01 to 1% by weight.

However, additional amounts of antioxidant may also be added if it is desired to tailor the induction period. Preferably, the concentration of any antioxidant in the masterbatch composition is less than 1000 ppm.

Other additives which can be included in the masterbatch composition include, but are not necessarily limited to, fillers, pigments, dyestuffs, stabilizers, processing aids, plasticizers, fire retardants, and anti-fog agents, among others.

The masterbatch composition is compounded, viz., the cobalt stearate and oxidizable resin, and other additives that may be present, are formed into a homogeneous solid. More details of the making of a masterbatch are provided below.

In another embodiment, the present invention relates to a method of making the masterbatch composition, comprising compounding the cobalt stearate with the oxidizable resin. Typically, compounding involves blending solid formulations (pellets or powders) of the cobalt stearate and the oxidizable resin under a temperature greater than the melting temperatures of the cobalt stearate and the resin to form a melt, with subsequent extrusion and pelletizing of the melt. Compounding apparatus are well known in the art, such as a Haake extruder or Brabender extruder, among others.

An advantage imparted to the masterbatch by compounding is an increase in the catalytic activity and a shortening in the induction time for oxygen scavenging of oxygen scavenging material made from the masterbatch. Though not to be bound by theory, it is believed this is a result of elevated temperatures during compounding. Elevated temperatures promote radical formation in the oxidizable resin. The presence of radicals makes oxygen scavenging more rapid after initiation.

Alternatively, the masterbatch can be prepared by coating of the cobalt stearate on pellets of the oxidizable resin. Coating on the pellets can be by solvent coating or powder coating. Additives, such as a photoinitiator or an antioxidant, among others, can be coated by the same techniques, either as a mixture with the cobalt stearate with coating of the mixture, or in a step following coating of the cobalt stearate.

An advantage of cobalt stearate over cobalt oleate in processing lies in the formation of the masterbatch. Cobalt stearate is a solid at ambient temperature, and so can be added to the masterbatch as such. Cobalt oleate, on the other hand, is a tacky solid at ambient temperature, and is generally provided as a 50% solution in toluene. The toluene solvent must be removed before masterbatching of cobalt oleate, and toluene carries a number of disposal concerns.

Both these issues can be removed by working with cobalt stearate.

In another embodiment, the present invention relates to a method of making a film, comprising (i) first providing a masterbatch comprising cobalt stearate and a first oxidizable resin compounded together; (ii) second providing a composition comprising a second oxidizable resin; (iii) combining the masterbatch and the composition, to form a blend; and (iv) forming the blend into a packaging article.

The masterbatch is as described above, and is preferably made as described above.

The second oxidizable resin can be any resin described above, and is preferably the same as or compatible with the first oxidizable resin and any inert carrier resin that may be present. More preferably, the second oxidizable resin is EMCM. The composition can optionally further comprise inert carrier resins, photoinitiators, antioxidants, and other additives as described above.

Combining the masterbatch and the composition into the blend can occur through any mechanism amenable to later extrusion of the blend. Typically, the components will be blended using a Haake extruder, Brabender extruder, or other similar apparatus.

The masterbatch and composition can be present in the blend in any concentrations found to be useful in preparing an oxygen scavenging article. Preferably, the masterbatch is present from about 10 wt% to about 15 wt% of the blend, and the composition is present from about 85 wt% to about 90 wt% of the blend.

After blending, the blend is formed into a packaging article. A packaging article is defined as any article comprising the blend and useful in packaging a product. The packaging article can be a single layer film, a multilayer film, a single layer rigid packaging article, or a multilayer rigid packaging article, among others. Other components can be used with the blend to form the packaging article.

In all cases, the packaging article, by comprising cobalt stearate and an oxidizable resin, will be capable of scavenging oxygen. The rate of oxygen scavenging can be increased, and the induction time of oxygen scavenging after initiation decreased, using the present blend over cobalt stearate-containing oxygen scavenging compositions wherein the cobalt stearate was not prepared in a masterbatch as described above.

Packaging articles typically come in several forms including rigid containers, flexible bags, or combinations of both, among others. Typical rigid or semirigid articles include plastic, paper or cardboard cartons or bottles such as juice containers, soft drink containers, thermoformed trays, or cups, which have wall thicknesses in the range of 100 to 1000 micrometers. Typical flexible bags include those used to package many food items, and will likely have thicknesses of 5 to 250 micrometers. The walls of such articles either comprise single or multiple layers of material. The blend can also be a formed as a component of packaging which has at least one non-integral oxygen-scavenging component or layer, e. g., a coating, a bottle cap liner, an adhesive or non-adhesive sheet insert, a gasket, a sealant, or a fibrous mat insert, among others.

The packaging article comprising the blend can be used to package any product for which it is desirable to inhibit oxygen damage during storage, e. g. food, beverage, pharmaceuticals, medical products, corrodible metals, or electronic devices.

The packaging article comprising the blend can comprise the single blend or the blend and additional components, such as oxidizable resins, or structural polymers such as the inert carrier resins listed above, among others. Single layered packaging articles can be prepared by solvent casting or by extrusion. Packaging articles with multiple layers are typically prepared using coextrusion, coating, or lamination.

The additional layers of a multilayered material may comprise at least one oxygen barrier layer, i. e. a layer having an oxygen transmission rate equal to or less than 500 cubic centimeters per square meter (cc/m2) per day per atmosphere at room temperature (about 25°C). Typical oxygen barriers comprise poly (ethylene vinylalcohol), polyacrylonitrile, polyvinyl chloride, poly (vinylidene dichloride), polyethylene terephthalate, silica, polyamides, or mixtures thereof.

Other additional layers of the packaging article may include one or more layers which are permeable to oxygen. In one packaging article, preferred for flexible packaging of food, the layers include, in order starting from the outside of the package to the innermost layer of the package, (i) an oxygen barrier layer, (ii) the oxygen scavenging layer comprising the blend, and optionally, (iii) an oxygen permeable layer. Control of the oxygen barrier property of (i) allows regulation of the scavenging life of the package by limiting the rate of oxygen entry to the oxygen scavenging layer (ii), and thus slows the consumption of oxygen scavenging capacity. Control of the oxygen permeability of layer (iii) allows setting an upper limit on the rate of oxygen scavenging for the overall structure independent of the composition of the oxygen scavenging layer (ii). This can extend the handling lifetime of the film in the presence of air prior to sealing of the package. Furthermore, layer (iii) can provide a barrier to migration of the components of the film, or by-products of scavenging, into the package interior. Even further, layer (iii) can improve the heat-sealability, clarity, or resistance to blocking of the multilayer packaging article.

Further additional layers, such as adhesive layers, may also be used. Compositions typically used for adhesive layers include anhydride functional polyolefins and other well- known adhesive layers.

The following examples are included to demonstrate preferred embodiments of the invention. It should be appreciated by those of skill in the art that the techniques disclosed in

the examples which follow represent techniques discovered by the inventor to function well in the practice of the invention, and thus can be considered to constitute preferred modes for its practice. However, those of skill in the art should, in light of the present disclosure, appreciate that many changes can be made in the specific embodiments which are disclosed and still obtain a like or similar result without departing from the spirit and scope of the invention.

Example 1 A masterbatch sample was made by compounding 60 g tribenzoyl triphenylbenzene and 637 g cobalt stearate (60 g cobalt) with 5363 g of 90/10 ethylene/vinyl acetate copolymer (9% vinyl acetate) (EVA-9)/ethylene/methyl acrylate/cyclohexenyl methyl acrylate terpolymer (EMCM) (i. e. 4827 g EVA-9 and 536 g EMCM) in a Haake extruder. The extruded masterbatch was pelletized.

The pelletized masterbatch was then blended in a 10/90 ratio with EMCM (e. g. 6060 g masterbatch to 54,540 g EMCM) in a Haake extruder, and subsequently extruded into a film using a Rindcastle minitruder.

Oxygen uptake of the film was then measured. After an induction period of about 1 day, the film scavenged oxygen. After 6 days at 4°C, the oxygen uptake of the film was roughly equal to that of a control film comprising EMCM and cobalt oleate.

All of the compositions and methods disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the compositions and methods of this invention have been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations may be applied to the compositions and methods and in the steps or in the sequence of steps of the method described herein without departing from the concept, spirit and scope of the invention. More specifically, it will be apparent that certain agents which are both chemically and physiologically related may be substituted for the agents described herein while the same or similar results would be achieved. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope and concept of the invention as defined by the appended claims.