Use of thermoplastic copolyester or copolyamide elastomer to increase oxygen scavenger activity of functionalized polyolefin films

[0001] There are many products that must be kept in a closed volume or in packaging with little or almost no oxygen. These oxygen sensitive products include pharmaceuticals, foodstuffs, meats, drinks etc. which are susceptible to degradation due to the presence of oxygen. Limiting oxygen exposure provides a means to maintain and increase the quality and shelf life of the packaged product. Removing oxygen from packaged products and creating barriers to oxygen penetration during storage is an important goal for a technologist in the field of food packaging. For example, packaging a food product in a package that minimizes oxygen exposure is a means of maintaining the quality of the product being packaged for a longer period of time and preventing deterioration of the product, so that its inventory is maintained longer without loss and the need to replenish and replace inventory.

[0002] Several techniques have been developed in the food packaging industry to limit the oxygen exposure of packaged oxygen sensitive materials. Such techniques include the use of barrier material (low oxygen permeability) as part of the package; the inclusion of certain agents that may consume oxygen, other than packaging material (by using sachets with material capable of reacting with oxygen); and creating a reduced oxygen environment in the packaging (e.g., modified atmosphere packaging - MAP- and vacuum packaging).

Even if each of the above techniques has its place in industry, it is well known that the use of an oxygen binding agent as part of a packaged article is one of the most desirable means of limiting oxygen exposure.

[0003] An oxygen-sensitive product, especially food, drink and medicine, breaks down or breaks down in the presence of oxygen. One approach to overcoming these difficulties is packaging such products using packaging materials containing at least one layer of foil as a so-called "passive" gas barrier, which can act as a physical oxygen barrier but does not react with oxygen. Films obtained from ethylene-vinyl alcohol (EVOH) or polyvinylidene chloride (PVDC) are commonly used for this purpose because of their excellent oxygen barrier properties. By physically blocking the passage of oxygen, such barrier films can maintain or substantially maintain the initial levels of oxygen in the package. However, due to the fact that films forming a passive barrier can increase the cost of packaging design and do not reduce the levels of oxygen already present in the packaging design, there is a need for effective, cheaper solutions and improvements. The solution to achieve or maintain an atmosphere with a low oxygen content inside the package is to use a package containing oxygen absorbing material. The package, sometimes also referred to as a cushion or sachet, is placed inside the packaging along with the product. Sakamoto et al. disclosed oxygen absorbing packages in the liner of Japanese Patent Application No. 121634/81 (1981). A typical ingredient used in the oxygen binding agent included in the packet is reduced iron powder, which can react with oxygen to form ferrous oxide or ferric oxide, as disclosed in US-A-4,856650. Furthermore, it is known to package, together with iron, a reaction promoter such as sodium chloride and a water absorbing agent such as silica gel as described in US-A-4992410. Japanese Patent Application Liner No. 82-24634 (1982) discloses an oxygen absorbing composition containing 100 parts by weight (cw) of iron powder, 2 to 7 cw of ammonium chloride, 8 to 15 cw of aqueous acid, 20 to 50 cw poorly water-soluble filler, such as activated clay. Japanese Patent Application Laid-Open No. 79-158386 (1979) discloses an oxygen-retaining composition containing a metal such as iron, copper or zinc, and optionally a metal halide such as sodium chloride or zinc chloride in an amount of 0.001 to 100 cw per 1 cw metal, and a filler such as clay in an amount of 0.01 to 100 cw per 1 cw of metal.

Although oxygen absorbing or binding materials used in packages may chemically react with the oxygen in the packaging, sometimes also referred to as "oxygen in the gas phase over the product," they do not prevent oxygen from entering the packaging from outside. Accordingly, the packages in which such packages are used commonly contain additional protection, such as wrappers or films constituting the passive barrier of the type described above. This increases the cost of the product. For many easy-to-prepare food products, another difficulty with oxygen-binding packets is that consumers can mistakenly open them and consume their contents with food. In addition, an additional production step, placing the packet in the container, can increase the cost of the product and slow down production. In addition, oxygen absorbing packages are not useful for liquid products.

In the light of these drawbacks and limitations, it has been proposed to incorporate directly into the walls of the packaging product a so-called "active" oxygen absorber, e.g. one that reacts with oxygen. Because such a packaging product is made to contain material that reacts with oxygen permeating through its walls, it is said that such packaging provides an "active barrier" as opposed to films that are a passive barrier that blocks oxygen but does not react with it. . Packaging with an active barrier is an attractive way to protect products sensitive to oxygen, as it can not only prevent oxygen from entering the product from the outside, but it can also absorb oxygen present in the container. One solution to obtain an active barrier packaging is to introduce a mixture of oxidizable metal (e.g. iron) and electrolyte (e.g. sodium chloride) to a suitable resin, melt processing to form single-layer or multi-layer sheets or film, and shaping from sheets or films containing oxygen binding agent of rigid or flexible containers or other packaging products or components. This type of active barrier is disclosed in Japanese Patent Application Liner No. 56-60642 (1981) regarding an oxygen absorbing sheet made of a thermoplastic resin containing iron, zinc or copper and a metal halide. The disclosed resins include polyethylene and polyethylene terephthalate. Sodium chloride is the preferred metal halide. The proportions of the components are such that 1 to 500 parts of metal halide per 100 parts of resin are present and 1 to 200 parts of metal halide per 100 parts of metal is present. Similarly, US-A-5153038 discloses multi-layered plastic vessels with different layer structure, made of a resin composition made by introducing an oxygen binding agent and optionally a water binding agent into the gas barrier resin. The oxygen binding agent may be a metal powder, such as iron, metal oxides of low valence or reducing metal compounds. The oxygen binding agent can be used in combination with an excipient such as hydroxide, carbonate, sulfite, thiosulfite, tertiary phosphate, secondary phosphate, organic acid salt or alkali metal or alkaline earth metal halide. The water-binding agent may be an inorganic salt such as sodium chloride, calcium chloride, zinc chloride, ammonium chloride, ammonium sulfate, sodium sulfate, magnesium sulfate, disodium hydrogen phosphate, sodium dihydrogen phosphate, potassium carbonate or sodium nitrate. The oxygen binding agent may be present in an amount of 1 to 1000% by weight based on the weight of the barrier resin. The water-binding agent may be present in an amount of 1 to 300% by weight based on the weight of the barrier resin.

One of the problems with binder systems containing an oxidizable metal (e.g. iron) and a metal halide (e.g. sodium chloride) in the thermoplastic layer is the lack of oxidation reaction efficiency. In order to achieve sufficient oxygen uptake in an active barrier package, a high load of the binder composition is often used. This usually requires that sheets, films and other packaging layer or wall structures containing the binder composition are relatively thick. This in turn contributes to the cost of the packaging material and may prevent thin packaging films with adequate oxygen binding capacity.

Another oxygen binding composition disclosed in US-A-4104192 contains ditionin and at least one compound containing crystallization water or hydration water. These compounds include various hydrated sodium salts, including carbonate, sulfate, sulfite and phosphates; in particular sodium pyrophosphate decahydrate is mentioned. As disclosed in Table 1, Example 1 in this patent, sodium pyrophosphate decahydrate was the least effective compound tested. In addition, the use of hydrate-containing compounds may not be useful for oxygen-binding resins that require high temperature processing. US-A-5744056, US-A6369148 and US-A-6586514 describe an oxygen-binding composition comprising an oxidizable metal component and an electrolyte component, as well as a non-electrolyte acidifying component that is thermally stable at thermoplastic melt production temperatures. WO2006 / 089895 discloses a similar system in which the electrolyte component involved in the oxidation reaction is obtained by hydrolysis of the Lewis acid salt and / or its adducts. One of the problems with this type of binding systems is the relative inefficiency of the oxidation reaction in the polymer matrix. Indeed, the binder composition must usually be used under heavy load, which leads to problems with cost, compatibility, transparency and color. In EP-A-1423456, the metal concentration is limited to less than 0.25% to obtain a more transparent plastic product, which significantly limits its effectiveness. Accordingly, while many approaches have been developed to maintain or reduce oxygen levels in packaging articles, there remains a need for an improved oxygen-binding composition and packaging materials using it.

The object of the present invention is therefore to provide improved oxygen-binding compositions and packages. Another goal is to provide low cost oxygen binding compositions with increased efficacy. Another goal is to provide an oxygen binding composition that can be effectively used, even in relatively small amounts, in a wide range of active barrier films and packaging sheets, including laminated and coextruded multilayer films and sheets. Another goal is to provide packaging containers with an active barrier that can provide an increased shelf life of oxygen sensitive products by slowing the passage of oxygen from outside to the container and / or by absorbing oxygen present within the container. Other objectives will become apparent to those skilled in the art.

[0004] It has been observed that by mixing copolyamide or copolyester thermoplastic elastomers, preferably based on polybutylene terephthalate (PBT), polytetrahydrofuran (p-THF), polydimethylene oxide (p-TMO), polyethylene glycol (pTMeG), polyolefin, butyl or glycol (PBA), which are thermally stable at temperatures usually used in processing thermoplastic resins, and used in conjunction with electrolytes and non-electrolyte acidifying components, the amount of oxygen capable of reacting with each unit of oxidizable metal particles, such as those described in US-A-5744056, US-A-6369148, US-A-6586514 and WO2006 can be increased / 089895). In particular, this applies to particles whose larger dimension is between 1000 μm and 10 gm, most preferably between 10 μm and 300 μm, and especially in the range of 10 Lim to 50 Lim. Accordingly, the oxidation reaction is easier and the overall oxygen binding efficiency may increase. This greater reactivity can be used practically to achieve higher reaction rates and range (greater binding capacity and speed) or, by reducing the amount of binder composition to contact the target environment, to achieve the same reaction rates and ranges with even clearer and more transparent plastic foil or container.

[0005] Accordingly, the present invention relates to an oxygen binding composition comprising (I) an oxidizable metal component, (II) electrolyte component, (III) non-electrolyte acidifying component, and (IV) copolyester or copolyamide thermoplastic elastomer.

[0006] The present invention further relates to an article containing such an oxygen binding composition, premixtures containing such an oxygen binding composition, and the use of said oxygen binding composition in food packaging.

[0007] According to the invention, the oxidizable metal may be Al, Mg, Zn, Cu, Fe, Sn, Co or Mn, although Fe is preferred because of the balance between price and reactivity. Also alloys or mixtures of such metals or such metals with other components are useful. The particles can have any shape, such as spherical, octagonal, cubic, in the form of rods or plates and the like. They can be functionalized for better dispersion in the polymer matrix or for optimal reactivity. However, preferred metal particles are not functionalized or stabilized by specific binding or interaction with polymeric, organic or organometallic compounds impermeable to oxygen transport.

The sum of the oxidizable metal, electrolyte, non-electrolyte acidifying component and elastomer based on a thermoplastic copolyester can form 2 to 60% of the total composition, the remainder being a polymer resin.

[0008] The weight ratio of electrolyte to non-electrolyte acidifying component may range from 10/90 to 90/10.

[0009] The sum of the electrolyte and non-electrolyte acidifying component may constitute 20 to 500 parts by weight per 100 parts of metal.

[0010] In addition, the weight ratio of the elastomer based on thermoplastic copolyester or copolyamide to electrolyte may range from 10/90 to 90/10. The sum of the electrolyte and the thermoplastic elastomer can be 20 to 500 parts by weight per 100 parts of metal. In addition, the weight ratio between the thermoplastic elastomer and the polymer resin can range from 10/90 to 90/10. The oxidizable metal is, for example, Al, Mg, Zn, Cu, Fe, Sn, Co or Mn, preferably Fe. Also alloys or mixtures of such metals or such metals with other components are useful. The metal particles can have any shape, such as spherical, octagonal, cubic, in the form of rods or plates and the like. They can be functionalized for better dispersion in the polymer matrix or for optimal reactivity. However, preferred metal particles are not functionalized or stabilized by specific binding or interaction with polymeric, organic or organometallic compounds impermeable to oxygen transport.

[0012] The oxidizable metal particles are in particular particles whose largest dimension is 10 μm to 1000 gm, preferably 10 μm to 300 μm, and most preferably 10 μm to 50 Lim to increase the amount of oxygen capable of reacting with each metal unit.

[0013] The non-electrolyte acidifying component includes various non-electrolyte organic and inorganic acids and their salts. Examples of specific compounds include anhydrous citric acid, monosodium salt of citric acid, ammonium sulfate, magnesium sulfate, disodium dihydrogen pyrophosphate, also known as sodium acid pyrophosphate (Na2H2P2O7), sodium metaphosphate, sodium trimetaphosphate, sodium hexametaphosphate, sodium phosphate aluminum sulfate, nicotinic acid, aluminum ammonium sulfate, monobasic sodium phosphate and aluminum potassium sulfate. Combinations of such materials may also be used.

[0014] A particularly preferred non-electrolyte acidifying component includes as component (III) acid alkali metal pyrophosphate or alkaline earth metal acid pyrophosphate and optionally additionally as component (IIIa) alkali metal dihydrogen phosphate (e.g. NaH2PO4) or alkaline earth metal dihydrogen phosphate. Preferably at least 1 part, especially 1 to 10 parts, by weight of component (IIIa) is used per 100 parts by weight of component (III).

[0015] A particularly preferred thermoplastic elastomer is a copolymer comprising completely polymerized hard and soft segments. The hard segments are crystallizable polyethylene terephthalate (PBT); soft segments are amorphous polyesters or polyethers. In particular, soft segments may consist of one or more of the following compounds: polytetrahydrofuran (p-THF), polytrimethylene glycol (p-TMeG), trimethylene oxide (p-TMO), butyl polyacrylate (PBA), based on polyolefins, glycol and butyl polyacrylate (PBA).

[0016] Therefore, preferred thermoplastic elastomers are based on PBT / p-THF, PBT / p-TMeG, PBT / p-TMO, PBT / PBA, PBA / glycol and PBT / polyolefin. Accordingly, copolyesters based on polyethylene terephthalate and / or butyl polyacrylate are particularly preferred.

[0017] The thermoplastic elastomer used in the composition of the invention preferably has a melting point between 180 and 280 ° C, especially between 200 and 230 ° C. [0018] Preferred copolyester thermoplastic elastomers have a Mw of 1000 to 10,000 daltons, preferably 2,000 to 6,000 daltons.

[0019] The present invention especially relates to an oxygen binding composition comprising (I) an oxidizable metal component, (II) an electrolyte component selected from the group consisting of NaCl, KCl and CaCl2, (III) a non-electrolyte acidifying component, preferably an acid alkali metal acid or acid pyrophosphate alkaline earth metal pyrophosphate, and (IV) thermoplastic elastomer based on PBT / p-THF, PBT / p-TMeG, PBT / p-TMO, PBT / PBA, PBT / glycol or PBT / polyolefin.

[0020] A particularly preferred oxygen binding composition according to the present invention comprises as component (I) iron, as component (II) NaCl, KCl or CaCl2 and as component (III) Na2H2P2O7 or CaH2P2O7;

as component (IV) a thermoplastic elastomer based on PBT / p-THF, PBT / p-TMeG, PBT / pTMO, PBT / PBA, PBT / glycol or PBT / polyolefin;

and further optionally as component (IIIa) NaH2PO4, KH2PO4 or Ca (H2PO4) 2.

[0021] Of particular interest is the oxygen-binding composition comprising as component (I) Fe, as component (II) NaCl, as component (III) Na2H2P2O7, as component (IV) a copolyester thermoplastic elastomer, preferably a copolyester based on polyethylene terephthalate and / or polyacrylate butyl; and optionally as component (IIIa) NaH2PO4.

[0022] The components of the present oxygen binding compositions are present in proportions effective to provide an oxygen binding effect. Preferably, at least 1 part by weight of the electrolyte component plus the acidifying component is present per 100 parts by weight of the oxidizable metal component, with a weight ratio of the electrolyte component to the non-electrolyte acidifying component, e.g. 99: 1 to 1:99, especially 10:90 to 90: 10. More preferably, at least about 10 parts of the electrolyte plus non-electrolyte acidifying components are present per 100 parts of the oxidizable metal component to assist in the efficient use of the latter in reaction with oxygen. To achieve a favorable combination of oxidation efficiency, low price and easy processing and handling, 20 to 500, especially 30 to 130 parts of electrolyte plus non-electrolyte acidifying components per 100 parts of metal component are most preferred.

[0023] According to a preferred embodiment, the oxygen binder composition may further comprise a water absorbing binder to further increase the oxidative efficiency of the oxidizable metal. The binder can also be used to provide additional moisture that intensifies metal oxidation in the presence of promoter compounds. Useful water absorbing binders typically include materials that absorb at least about 5 percent of their own weight water and are chemically inert. Examples of suitable binders include diatomaceous earth, boehmite, kaolin clay, bentonite clay, acid clay, activated clay, zeolite, molecular sieves, talc, calcined vermiculite, activated carbon, graphite, soot and the like. The use of organic binders, examples of which include the various water-absorbing polymers disclosed in EP-A-428736, is also contemplated. Mixtures of such binders may also be used. Preferred binders include bentonite clay, kaolin clay and silica gel.

[0024] If present, the water-absorbing binder is preferably used in an amount of e.g. 5 to 100 parts per 100 parts of metal. When the binder component is used in compositions mixed into the plastic, the binder is most preferably present in an amount of 10 to 50 parts per 100 parts of metal to enhance oxidation efficiency at load levels low enough to ensure ease of processing.

[0025] Another embodiment of the present invention relates to the oxygen-binding composition as defined above and optionally including the usual additive and subsequently as component (V) an additional polymeric resin other than component (IV) according to the invention.

Examples of such polymer resins are:

[0026]

1. Polymers of monoolefins and diolefins, for example polypropylene, polyisobutylene, polybut-1-ene, poly-4-methylpent-1-ene, polyvinylcyclohexane, polyisoprene or polybutadiene, as well as polymers of cycloolefins, e.g. cyclopentene or norbornene, polyethylene (which may be optionally crosslinked) , for example, high-density polyethylene (HDPE), high-density polyethylene (HDPEHMW), high-density polyethylene (HDPEUHMW), medium density polyethylene (MDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), (VLDPE) and (ULDPE).

Polyolefins, e.g. monoolefin polymers, examples of which are given in the previous paragraph, preferably polyethylene and polypropylene, can be prepared by various, in particular the following methods:

a) radical polymerization (usually under high pressure and at elevated temperature).

b) catalytic polymerization using a catalyst which usually contains one or more metals from groups IVb, Vb, VIb and VIII of the periodic table. Such metals usually contain one or more ligands, usually oxides, halides, alcoholates, esters, ethers, amines, alkyls, alkenyls and / or aryls which can be π- or σ-coordinated. Such metal complexes can be in free form or deposited on substrates, usually on active magnesium chloride, titanium (III) chloride, alumina or silica. Such catalysts may be soluble or insoluble in the polymerization medium. The catalysts themselves may be used in the polymerization or additional activators may be used, usually alkylmetals, metal hydrides, alkyl metal halides, alkyl metal oxides or metal alkyloxanes, which metals are elements from groups Ia, IIa and / or IIIa of the Periodic Table. Activators can be conveniently modified with additional ester, ether, amino or silyl groups. Such catalyst systems are usually referred to as Phillips, Standard Oil catalysts

Indiana, Zieglera (-Natty), TNZ (DuPont), metallocene or single point (SSC).

2. Mixtures of the polymers mentioned in 1), for example mixtures of polypropylene with polyisobutylene, polypropylene with polyethylene (for example PP / HDPE, PP / LDPE) and mixtures of different types of polyethylene (for example LDPE / HDPE).

3. Copolymers of monoolefins and diolefins with each other and with other vinylic monomers, for example ethylene / propylene copolymers, linear low density polyethylene (LLDPE) and mixtures thereof with low density polyethylene (LDPE), propylene / but-1-ene copolymers, propylene / isobutylene copolymers , ethylene / but-1ene copolymers, ethylene / hexene copolymers, ethylene / methylpentene copolymers, ethylene / heptene copolymers, ethylene / octene copolymers, ethylene / vinylcyclohexane copolymers, ethylene / cycloolefin copolymers (e.g. ethylene / norbornene (such as COC), ethylene / 1-olefin copolymers, where 1-olefin is generated in-situ; propylene / butadiene copolymers, isobutylene / isoprene copolymers, ethylene / vinylcyclohexene copolymers, ethylene / alkyl acrylate copolymers, ethylene / alkyl methacrylate copolymers, ethylene / vinyl acetate copolymers or ethylene / acrylic acid copolymers and their salts (also ionomers) propylene and diene such as hexadiene, dicyclopentadiene or ethylidene norbornene; and mixtures of such copolymers with one another or with the polymers mentioned above in 1), for example polypropylene / ethylene propylene copolymers, LDPE / ethylene vinyl acetate (EVA) copolymers, LDPE / ethylene acrylic acid (EAA) copolymers, LLDPE / EVA, LLDPE / EAA and alternating or random polyalkylene / carbon monoxide copolymers and mixtures thereof with other polymers.

4. Hydrocarbon resins (for example C5-C9) including their hydrogenated modifications (e.g., binders) and mixtures of polyalkylenes and starches.

Homopolymers and copolymers 1.) - 4.) may have any spatial structure, including syndiotactic, isotactic, semiisotactic or atactic; atactic polymers are preferred. Stereoblock polymers are also included.

5. Polystyrene, poly (p-methylstyrene), poly (α-methylstyrene).

6. Aromatic homopolymers and copolymers derived from vinylaromatic monomers including styrene, α-methylstyrene, all vinyltoluene isomers, in particular p-vinyltoluene, all ethylstyrene isomers, propylstyrene, vinylbiphenyl, vinylnaphthalene and vinylanthracene, and mixtures thereof. Homopolymers and copolymers may have any spatial structure, including syndiotactic, isotactic, semiisotactic or atactic; atactic polymers are preferred. Stereoblock polymers are also included.

6a. Copolymers including the aforementioned vinylaromatic monomers and comonomers selected from ethylene, propylene, dienes, nitriles, acids, maleic anhydrides, maleimides, vinyl acetate and vinyl chloride or acrylic derivatives and mixtures thereof, for example styrene / butadiene, styrene / acrylonitrile, styrene / ethylene ( interpolymers), styrene / alkyl methacrylate, styrene / butadiene / alkyl acrylate, styrene / butadiene / alkyl methacrylate, styrene / maleic anhydride, styrene / acrylonitrile / alkyl acrylate; mixtures of high-impact copolymers of styrene and another polymer, for example polyacrylate, diene polymer or ethylene / propylene / diene terpolymer; and styrene block copolymers such as styrene / butadiene / styrene, styrene / isoprene / styrene, styrene / ethylene / butylene / styrene or styrene / ethylene / propylene / styrene.

6b. Hydrogenated aromatic polymers derived from hydrogenation of the polymers mentioned in 6.), especially including polycyclohexylethylene (PCHE) obtained by hydrogenation of atactic polystyrene, often referred to as polyvinylcyclohexane (PVCH).

6c. Hydrogenated aromatic polymers derived from hydrogenation of the polymers mentioned in 6a.)

Homopolymers and copolymers may have any spatial structure, including syndiotactic, isotactic, semiisotactic or atactic; atactic polymers are preferred. Stereoblock polymers are also included.

7. Grafted copolymers of vinylaromatic monomers such as styrene or α-methylstyrene, for example styrene on polybutadiene, styrene on polybutadienerene or polybutadiene-acrylonitrile copolymers; styrene and acrylonitrile (or methacrylonitrile) on polybutadiene; styrene, acrylonitrile and methyl methacrylate on polybutadiene; styrene and maleic anhydride on polybutadiene; styrene, acrylonitrile and maleic anhydride or maleimide on polybutadiene; styrene and maleimide on polybutadiene; styrene and alkyl acrylates or methacrylates on polybutadiene; styrene and acrylonitrile on ethylene / propylene / diene terpolymers; styrene and acrylonitrile on alkyl polyacrylates or polyalkyl methacrylates, styrene and acrylonitrile on acrylate / butadiene copolymers, as well as mixtures thereof with the copolymers mentioned in 6), for example mixtures of copolymers known as polymers ABS, MBS, ASA or AES.

8. Polymers containing halogen, such as polychloroprene, chlorinated rubbers, chlorinated and brominated isobutylene-isoprene copolymer (halobutyl rubber), chlorinated or sulfochlorated polyethylene, ethylene and chlorinated ethylene copolymers, epichlorohydrin homo- and copolymers, especially polyvinyl compounds, polyvinyl compounds , polyvinylidene chloride, polyvinyl fluoride, polyvinylidene fluoride, as well as their copolymers, such as vinyl chloride / vinylidene chloride, vinyl chloride / vinyl acetate or vinylidene chloride / vinyl acetate copolymers.

9. Polymers derived from α, β-unsaturated acids and their derivatives, such as polyacrylates and polymethacrylates; polymethyl methacrylates, polyacrylamides and polyacrylonitriles, with impact strength modified by butyl acrylate.

10. Copolymers of the monomers mentioned in 9) one with the other or with other unsaturated monomers, for example acrylonitrile / butadiene copolymers, acrylonitrile / alkyl acrylate copolymers, acrylonitrile / alkoxyalkyl acrylate or acrylonitrile / vinyl halide or acrylonitrile acrylonitrile acrylonitrile

11. Polymers derived from unsaturated alcohols and amines or their acyl derivatives or acetals, for example polyvinyl alcohol, polyvinyl acetate, polyvinyl stearate, polyvinyl benzoate, vinyl polymaleate, polyvinyl butyral, allyl polyphthalate or polyallyl melamine; as well as their copolymers with the olefins mentioned above in 1).

12. Homopolymers and copolymers of cyclic ethers, such as polyalkylene glycols, polyethylene oxide, polypropylene oxide, or copolymers thereof with bisglycidyl ethers.

13. Polyacetals, such polyoxymethylene and those polyoxymethylenes that contain ethylene oxide as a comonomer; polyacetals modified with thermoplastic polyurethanes, acrylates or MBS.

14. Polyphenylene oxides and sulfides, and mixtures of phenylene oxides with styrene polymers or polyamides.

15. Polyurethanes derived from polyethers or polybutadienes terminated with hydroxyl groups on the one hand, and aliphatic or aromatic polyisocyanates on the other, as well as their precursors.

16. Polyamides derived from diamines and dicarboxylic acids and / or from aminocarboxylic acids or corresponding lactams, for example polyamide 4, polyamide 6, polyamide 6/6, 6/10, 6/9, 6/12, 4/6, 12/12, polyamide 11, polyamide 12, aromatic polyamides obtained from m-xylene diamine and adipic acid; polyamides obtained from hexamethylenediamine and isophthalic and / or terephthalic acid and polyamides condensed during processing (RIM polyamide systems).

17. Polyureas, polyimides, polyamide imides, polyetherimides, polyesterimides, polyhydantoins and polybenzimidazoles.

18. Polyesters derived from dicarboxylic acids and diols and / or from hydroxycarboxylic acids or the corresponding lactones or lactides, for example polyethylene terephthalate, polyethylene terephthalate, polyethylene terephthalate 1,4-dimethylol cyclohexane, polyalkylene terephthalate and polyhydroxybenzoates. In addition, aliphatic polyesters may include, for example, but not limited to, the class of poly (hydroxyalkanoates), especially poly (propiolactone), poly (butyrolactone), poly (pivalolactone), poly (valerolactone) and poly (caprolactone), ethylene polysuccinate, propylene polysuccinate, polysuccinate butylene, hexamethylene polysuccinate, polyethylene polyadinate, propylene polyadipate, butylene polyadipate, hexamethylene polyadipate, ethylene poly oxalate, propylene poly oxalate, butylene poly oxalate, hexamethylene oxalate, polyethylene polybate, propylene polybearate, butylene polybearate and poly lactic acid (PLA), as well as the corresponding polycarbonate or MBS modified polyesters. The term "poly lactic acid (PLA)" means a homopolymer, preferably poly-L-lactide, and any of its blends or alloys with other polymers; copolymer of lactic acid or lactide with other monomers, such as hydroxycarboxylic acids, such as, for example, glycolic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 4-hydroxyvaleric acid,

5-hydroxyvaleric, 6-hydroxycaproic acid and their cyclic forms; the terms "lactic acid" or "lactide" include L-lactic acid, D-lactic acid, mixtures thereof and dimers, e.g. L-lactide, D-lactide, mesolactide, and any mixtures thereof.

19. Polycarbonates and polyester carbonates.

twenty. Polyketones.

21. Polysulfones, polyethersulfones and polyetherketones.

22. Crosslinked polymers derived from aldehydes on the one hand, and phenols, ureas and melamines on the other, such as phenol / formaldehyde resins, urea / formaldehyde resins and melamine / formaldehyde resins.

23. Drying and non-drying alkyd resins.

24. Unsaturated polyester resins derived from saturated and unsaturated dicarboxylic acids with polyhydric alcohols and vinyl compounds as crosslinkers, as well as their halogen-containing low-flammability varieties.

25. Crosslinkable acrylic resins derived from suitable acrylates, for example epoxyacrylates, urethaneacrylates or polyesteracrylates.

26. Alkyd resins, polyester resins and acrylate resins crosslinked with melamine resins, urea resins, isocyanates, isocyanurates, polyisocyanates or epoxy resins.

27. Crosslinked epoxy resins derived from aliphatic, cycloaliphatic, heterocyclic or aromatic glycidyl compounds, e.g. products from bisphenol A and bisphenol F diglycidyl ethers, which are crosslinked with conventional hardeners such as anhydrides or amines, with or without accelerators.

28. Natural polymers such as cellulose, rubber, gelatin and their chemically modified homologous derivatives, for example cellulose acetates, cellulose propionates and butyrate cellulose, or cellulose ethers such as methyl cellulose; and rosins and their derivatives.

thirty. Naturally occurring and synthetic organic materials that are pure monomeric compounds or mixtures of such compounds, for example, mineral oils, fats, animal and vegetable oils and waxes, or oils, fats and waxes based on synthetic esters (e.g. phthalates, adipates, phosphates or trimellitates), as well as mixtures of synthetic esters with mineral oils in any weight ratio, usually those used as spinning compositions, as well as aqueous emulsions of such materials.

31. Aqueous emulsions of natural or synthetic rubber, e.g. natural latex or latexes of carboxylated styrene / butadiene copolymers.

[0027] According to a preferred embodiment of the present invention, the polymer resin is a homo or olefin copolymer, a polyamide homopolymer, a polyester with repeating units selected from the group consisting of terephthalic acid residues, isophthalic acid residues, naphthalene acid residues and mixtures thereof.

[0028] Any suitable polymer resin from the above list into which an effective amount of the oxygen-binding composition of the present invention can be incorporated and which can form a laminar configuration, such as a film, sheet or wall structure, can be used as a plastic resin in the compositions of this aspect of the invention . Thermoplastic and thermosetting resins that can be used are, for example, nylon 6, nylon 66 and nylon 612, linear and branched polyesters such as polyethylene terephthalate, polyethylene terephthalate and polyethylene terephthalate, polystyrenes, polycarbonate, unsubstituted, substituted or functionalized olefinic polymers polyvinyl chloride, polyvinylidene chloride, polyacrylamide, polyacrylonitrile, polyvinyl acetate, polyacrylic acid, vinyl methyl polyether, ethylene-vinyl acetate copolymer, ethylene-methyl acrylate copolymer, polyethylene, polypropylene, ethylene-propylene copolymers, poly (1-hexene), poly (4-methyl-1-pentene), poly (1-butene), poly (3- methyl-1-butene), poly (3-phenyl-1-propene) and poly (vinylcyclohexane).

The preferred polymers are, in particular, thermoplastic resins with oxygen transfer coefficients of more than 2x10 cm cm cm cm cm Hg, measured at 20 ° C and 0% relative humidity, since such resins are relatively inexpensive are easily formed into packaging structures and, when used with the oxygen-binding composition of the invention, can provide a high degree of active barrier protection for oxygen-sensitive products. Examples thereof include polyethylene terephthalate and poly-alpha-olefin resins such as high or low density polyethylene or low density linear polyethylene. Even relatively small amounts of oxygen-binding composition, e.g. 5 to 15 parts per 100 parts resin, can provide such resins with a high degree of oxygen barrier protection. Among these preferred resins, oxygen permeability increases in order of polyethylene terephthalate, polypropylene, high density polyethylene, linear low density polyethylene and low density polyethylene, with the other components being the same. Therefore, for such polymer resins, the load of oxygen binding agent to achieve a given level of effectiveness as an oxygen barrier increases in a similar order, with the other components being the same.

[0029] When choosing a thermoplastic resin for use or mixing with the oxygen binding composition of the invention, the presence of residual antioxidant compounds in the resin may adversely affect the oxygen absorption efficiency. Phenol-type antioxidants and phosphite-type antioxidants are commonly used by polymer manufacturers to increase the thermal stability of resins and fabricated products derived therefrom. Specific examples of such residual antioxidant compounds include materials such as butylated hydroxytoluene, tetrakis (methylene (3,5-di-t-butyl-4-hydroxyhydrocinnamate) methane and triisoctyl phosphite. Such antioxidants should not be confused with the oxygen binding components used in the present invention. . Typically, oxygen uptake by the binder compositions of the present invention is improved when the level of residual antioxidant compounds decreases. Accordingly, commercially available resins containing low levels of phenol type or phosphite type antioxidants, preferably below about 1600 ppm, and most preferably below about 800 ppm, based on the weight of the resin, are preferred (although not required) for use according to the present invention . Examples are linear low density polyethylene (LLDPE) Dowlex 2032 (RTM) from Dow Chemical; LLDPE GRSN 7047 (RTM) from Union Carbide; PET "Traytuf" 9506 m (RTM) from Goodyear; and Eastman PETG 6763 (RTM). The amount of residual antioxidant can be measured using high pressure liquid chromatography.

[0030] If desired, an additional one or more of the following conventional additives may be used in combination with the oxygen binder formulation; the list includes, for example, antioxidants, UV absorbents and / or additional light stabilizers, such as:

1. Alkylated monophenols, for example 2,6-di-tert-butyl-4-methylphenol, 2-tert-butyl-4,6-dimethylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,6-di-tert- butyl-4-n-butylphenol, 2,6-di-tert-butyl-4-isobutylphenol, 2,6-dicyclopentyl-4-methylphenol, 2- (α-methylcyclohexyl) -4,6-dimethylphenol, 2,6- dioctadecyl-4-methylphenol, 2,4,6-tricyclohexylphenol, 2,6-di-tert-butyl-4-methoxymethylphenol, linear or branched nonylphenols, for example 2,6-di-nonyl-4-methylphenol, 2,4-dimethyl-6- (1'-methyloundec-1'-yl) phenol, 2,4-dimethyl-6- (1'-methylheptadec-1'-yl) phenol, 2,4-dimethyl-6- (1'-methyltridec-1'-yl) phenol and mixtures thereof.

2. Alkylthiomethylphenols, for example 2,4-dioctylthiomethyl-6-tert-butylphenol,

2,4-dioctylthiomethyl-6-methylphenol, 2,4-dioctylthiomethyl-6-ethylphenol, 2,6-didodecylthiomethyl-4-nonylphenol.

3. Hydroquinones and alkylated hydroquinones, e.g. 2,6-di-tert-butyl-4-methoxyphenol, 2,5-di-tert-butylhydroquinone, 2,5-di-tert-amylhydroquinone, 2,6-diphenyl-4-octadecyloxyphenol, 2,6-di-tert-butyl hydroquinone, 2,5-di-tert-butyl-4-hydroxyanisole, 3,5-di-tert-butyl-4-hydroxyanisole, 3,5-di-tert-butyl-4 stearate -hydroxyphenyl, bis (3,5-di-tert-butyl-4-hydroxyphenyl) adipate.

4. Tocopherols, for example α-tocopherol, β-tocopherol, γ-tocopherol, δ-tocopherol and mixtures thereof (vitamin E).

5. Hydroxylated thiodiphenyl ethers, for example 2,2'-thiobis (6-tert-butyl-4-methylphenol), 2,2'-thiobis (4-octylphenol), 4,4'-thiobis (6-tert-butyl-3- methylphenol), 4,4'-thiobis (6-tert-butyl-2-methylphenol), 4,4'-thiobis (3,6-di-sec-amylphenol), disulfide 4,4'-bis (2.6 dimethyl-4-hydroxyphenyl).

6. Alkylidene bisphenols, for example 2,2'-methylene bis (6-tert-butyl-4-methylphenol),

2,2'-methylene bis (6-tert-butyl-4-ethylphenol), 2,2'-methylene bis [4-methyl-6- (α-methylcyclohexyl) phenol], 2,2'-methylene bis (4-methyl- 6-cyclohexylphenol), 2,2'-methylene bis (6-nonyl-4-methylphenol), 2,2'-methylene bis (4,6-di-tert-butylphenol), 2,2'-ethylidene bis (4,6- di-tert-butylphenol), 2,2'-ethylidene bis (6-tert-butyl-4-isobutylphenol), 2,2'-methylenebis [6- (α-methylbenzyl) -4-nonylphenol], 2,2'- methylene bis [6- (a, dimethylbenzyl) -4-nonylphenol], 4,4'-methylenebis (2,6-di-tert-butylphenol), 4,4'-methylene bis (6-tert-butyl-2-methylphenol), 1,1-bis (5-tert-butyl-4-hydroxy-2-methylphenyl) butane, 2,6-bis (3-tert- butyl-5-methyl-2-hydroxybenzyl) -4-methylphenol, 1,1,3-tris (5-tert-butyl-4-hydroxy-2-methylphenyl) butane, 1,1-bis (5-tert-butyl-4 -hydroxy-2-methylphenyl) -3-n-dodecylmercaptobutane, bis [3,3-bis (3'-tert-butyl-4'-hydroxyphenyl) butyrate] ethylene glycol, bis (3-tert-butyl-4-hydroxy -5-methylphenyl) dicyclopentadiene, Bis [2- (3'-tert-butyl-2'-hydroxy-5'-methylbenzyl) 6-tert-butyl-4-methylphenyl] terephthalate, 1,1-bis- (3,5-dimethyl-2-hydroxyphenyl) )butane,

2,2-bis (3,5-di-tert-butyl-4-hydroxyphenyl) propane, 2,2-bis (5-tert-butyl-4-hydroxy-2-methylphenyl) -4-n-dodecylmercaptobutane, 1 , 1,5,5-tetra- (5-tert-butyl-4-hydroxy-2-methylphenyl) pentane.

7. O-, N- and S-benzyl compounds, for example 3,5,3 ', 5'-tetra-tert-butyl-4,4'-dihydroxydibenzyl ether, octadecyl-4-hydroxy-3,5-dimethylbenzyl mercaptoacetate, mercaptoacetate tridecyl-4-hydroxy-3,5-di-tert-butylbenzyl, tris (3,5-di-tert-butyl-4-hydroxybenzyl) amine, bis (4-tert-butyl-3-hydroxy-2,6 dithiotherephthalate) -di12 methylbenzyl), bis (3,5-di-tert-butyl-4-hydroxybenzyl) sulfide, isooctyl-3,5-di-tert-butyl-4-hydroxybenzyl mercaptoacetate.

8. Hydroxybenzylated malonates, for example dioctadecyl 2,2-bis (3,5-di-tert-butyl-2-hydroxybenzyl) malonate, dioctadecyl 2- (3-tert-butyl-4-hydroxy-5-methylbenzyl) malonate -bis (3,5-di-tert-butyl-4-hydroxybenzyl) didodecylmercaptoethyl malonate, 2,2-bis (3,5-di-tert-butyl-4-hydroxybenzyl) bis malonate [4- (1,1, 3,3-tetramethylbutyl) phenyl].

9. Aromatic hydroxybenzyl compounds, for example 1,3,5-tris (3,5-di-tert-butyl-4-hydroxybenzyl) -2,4,6-trimethylbenzene, 1,4-bis (3,5-di-tert- butyl-4-hydroxybenzyl) -2,3,5,6-tetramethylbenzene, 2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) phenol.

10. Triazine compounds, for example 2,4-bis (octylmercapto) -6- (3,5-di-tert-butyl4-hydroxyanilino) -1,3,5-triazine, 2-octylomercapto-4,6-bis (3,5 -di-tert-butyl-4-hydroxyanilino) -1,3,5-triazine, 2-octylmercapto-4,6-bis (3,5-di-tert-butyl-4-hydroxyphenoxy) -1,3,5 -triazine, 2,4,6-tris (3,5-di-tert-butyl-4-hydroxyphenoxy) -1,2,3-triazine, 1,3,5-tris (3,5-di-tert-butyl isocyanurate -4-hydroxybenzyl), isocyanurate

1,3,5-tris (4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl), 2,4,6-tris (3,5-di-tert-butyl-4-hydroxyphenylethyl) -1, 3,5-triazine, 1,3,5-tris (3,5-di-tert-butyl-4-hydroxyphenylpropionyl) hexahydro-1,3,5-triazine, 1,3,5-tris isocyanurate (3,5 -dicykloheksylo-4-hydroxybenzyl).

11. Benzyl phosphonates, for example dimethyl 2,5-di-tert-butyl-4-hydroxybenzyl phosphonate, diethyl 3,5-di-tert-butyl-4-hydroxybenzyl phosphonate, dioctadecyl 3,5-di-tert-butyl 4-hydroxybenzyl phosphonate, 5-tert dioctadecyl-butyl-4-hydroxy-3-methylbenzylphosphonate, calcium salt of 3,5-ditert-butyl-4-hydroxybenzylphosphonic acid monoethyl ester.

12. Acylaminophenols, for example 4-hydroxylauranilide, 4-hydroxystearanilide, octyl N- (3,5-di-tert-butyl-4-hydroxyphenyl) carbamate.

13. E- (3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid esters with mono- or polyhydric alcohols, e.g. with methanol, ethanol, n-octanol, i-octanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, triethylene glycol tris (hydroxyethyl) isocyanurate, N, N'-bis (hydroxyethyl) oxamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl-1-phosphate-2,6,7-trioxabicyclo [2.2.2] octane.

14. E- (5-tert-butyl-4-hydroxy-3-methylphenyl) propionic acid esters with monohydric or polyhydric alcohols, e.g. with methanol, ethanol, n-octanol, i-octanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, triethylene glycol tris (hydroxyethyl) isocyanurate, N, N'-bis (hydroxyethyl) oxamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo [2.2.2] octane; 3,9-bis [2- {3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy} -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5.5] undecane.

15. E- (3,5-dicyclohexyl-4-hydroxyphenyl) propionic acid esters with mono- or polyhydric alcohols, e.g. with methanol, ethanol, octanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, isisocyanate, N, N'-bis (hydroxyethyl) oxamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo [2.2.2] octane.

16. Esters of 3,5-di-tert-butyl-4-hydroxyphenylacetic acid with mono- or polyhydric alcohols, e.g. methanol, ethanol, octanol, octadecanol,

1,6-hexanediol, 1,9-nonanediol, ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethylene glycol, triethylene glycol, pentaerythritol, tris (hydroxyethyl) isocyanurate, N, N'-bis oxamide, 3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol, trimethylolpropane, 4-hydroxymethyl-1-phospho-2,6,7-trioxabicyclo [2.2.2] octane.

17. E- (3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid amides, e.g. N, N'bis (3,5-di-tert-butyl-4-hydroxyphenylpropionyl) hexamethylenediamide, N, N'- bis (3,5-di-tert-butyl-4-hydroxyphenylpropionyl) trimethyldiamide, N, N'-bis (3,5-ditert-butyl-4-hydroxyphenylpropionyl) hydrazide, N, N'-bis [2- (3 - [3,5-di-tert-butyl4-hydroxyphenyl] propionyloxy) ethyl] oxamide (Naugard^®XL-1, provided by Uniroyal).

18. Ascorbic Acid (Vitamin C)

19. Amine antioxidants, for example N, N'-di-isopropyl-p-phenylenediamine, N, N'-di-sec-butyl-p-phenylenediamine, N, N'-bis (1,4-dimethylpentyl) -phenylenediamine, N, N'-bis (1-ethyl-3-methylpentyl) -p-phenylenediamine, N, N'-bis (1-methylheptyl) -p-phenylenediamine, N, N'-dicyclohexyl-p-phenylenediamine, N, N'-di phenyl -p-phenylenediamine, N, N'-bis (2-naphthyl) -p-phenylenediamine, N-isopropyl-N'-phenyl-p-phenylenediamine, N- (1,3-dimethylbutyl) -N'-phenyl-p- phenylenediamine, N- (1-methylheptyl) -N'-phenyl-p-phenylenediamine, N-cyclohexyl-N'-phenyl-phenylenediamine, 4- (p-toluenesulfamoyl) diphenylamine, N, N'-dimethyl-N, N'-di -secbutyl-p-phenylenediamine, diphenylamine, N-allyl diphenylamine, 4-isopropoxydiphenylamine, N-phenyl-1-naphthylamine, N- (4-tert-octylphenyl) -1-naphthylamine, N-phenyl-2-naphthylamine, octylated diphenylamine, for example p, p'-di-tertoctyldiphenylamine, 4-n-butylaminophenol, 4-butyrylaminophenol, 4-nonanoylaminophenol, 4-dodecanoylaminophenol, 4-octadecanoylaminophenol, bis (4-methoxyphenyl) amine, 2,6-di-tert-butyl-4-dimethylaminomethylphenol, 2,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, N, N, N ', N'- tetramethyl-4,4'-diaminodiphenylmethane, 1,2-bis [(2-methylphenyl) amino] ethane, 1,2-bis (phenylamino) propane, (o-tolyl) biguanide, bis [4- (1 ', 3 'dimethylbutyl) phenyl] amine, tert-octylated N-phenyl-1-naphthylamine, a mixture of mono- and dialkylated tert-butyl / tertoctyldiphenylamines, a mixture of mono- and dialkylated nonyl diphenylamines, mixture of mono- and dialkylated dodecyldiphenylamines, mixture of mono- and dialkylated isopropyl / isohexyldiphenylamines, mixture of mono- and dialkylated tert-butyldiphenylamines, 2,3-dihydro-3,3-dimethyl-4H-1,4-benzothiazine, phenothiazine, and dialkylated tert-butyl / tert-octylphenothiazines, a mixture of mono- and dialkylated tert-octylphenothiazines, N-allylphenothiazine, N, N, N ', N'-tetrafenyl-1,4-diaminobut-2-ene.

twenty. 2- (2'-Hydroxyphenyl) benzotriazole, for example 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (3 ', 5'-di-tert-butyl-2'-hydroxyphenyl) benzotriazole, 2- (5'-tert-butyl-2'-hydroxyphenyl) benzotriazole, 2- (2'-hydroxy-5 '- (1,1,3,3-tetramethylbutyl) phenyl) benzotriazole, 2- (3', 5 '- di-tert-butyl-2'-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3'-tert-butyl-2'-hydroxy-5'-methylphenyl) -5-chlorobenzotriazole, 2- (3'-sec-butyl -5'-tert-butyl-2'-hydroxyphenyl) benzotriazole, 2- (2'-hydroxy-4'-octyloxyphenyl) benzotriazole, 2- (3 ', 5'-di-tert-amyl-2'-hydroxyphenyl) benzotriazole, 2- (3', 5'-bis- (a , dimethyl benzyl) -2'-hydroxyphenyl) benzotriazole, 2- (3'-tert-butyl-2'-hydroxy-5 '(2-octyloxycarbonylethyl) phenyl) -5-chlorobenzotriazole, 2- (3'-tert-butyl- 5 '- [2- (2-ethylhexyloxy) carbonylethyl] -2'-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3'-tert-butyl-2'-hydroxy-5' - (2-methoxycarbonylethyl) phenyl) -5- chlorobenzo14 triazole, 2- (3'-tert-butyl-2'-hydroxy-5 '- (2-methoxycarbonylethyl) phenyl) benzotriazole, 2- (3'-tert-butyl-2'-hydroxy-5' - (2-octyloxycarbonylethyl) ) phenyl) benzotriazole, 2- (3'-tert-butyl-5 '- [2- (2-ethylhexyloxy) carbonylethyl] -2'-hydroxyphenyl) benzotriazole, 2- (3'-dodecyl-2'-hydroxy-5 '-methylphenyl) benzotriazole, 2- (3'-tert-butyl-2'-hydroxy-5' - (2-isooctyloxycarbonylethyl) phenylbenzotriazole, 2,2'-methylene-bis [4- (1,1,3,3-tetramethylbutyl ) -6-benzotriazol-2-ilofenol]; product of transesterification of 2- [3'-tert-butyl-5 '- (2-methoxycarbonylethyl) -2'-hydroxyphenyl] -2H-benzotriazole with polyethylene glycol 300; [R-CH₂CH₂COO-CH₂CH₂^₂, where R = 3'-tert-butyl-4'-hydroxy-5'-2H-benzotriazol-2-yl-phenyl, 2- [2'-hydroxy-3 '- (a, dimethylbenzyl) -5' - (1, 1,3,3-tetramethylbutyl) phenyl] benzotriazole; 2- [2'-hydroxy-3 '- (1,1,3,3-tetramethylbutyl) -5' - (a, a-dimethylbenzyl) phenyl] benzotriazole.

21. 2-Hydroxybenzophenones, for example 4-hydroxy, 4-methoxy, 4-octyloxy, 4-decyloxy, 4-dodecyloxy, 4-benzyloxy, 4,2 ', 4'-trihydroxy and 2'hydroxy-4,4'-dimethoxy derivatives.

22. Esters of substituted and unsubstituted benzoic acids, for example 4-tert-butylphenyl salicylate, phenyl salicylate, octylphenyl salicylate, dibenzoylresorcinol, bis (4-tert-butylbenzoyl) resorcinol, benzoylresorcinol, 2,4-di-tert-butylphenylene, 4 5-di-tert-butyl, 3,5-di-tert-butyl-4-hydroxybenzoate hexadecyl, 3,5-di-tert-butyl-4-hydroxybenzoate, octadecyl, 3,5-ditert-butyl-4-hydroxybenzoate 2 -methyl-4,6-di-tert-butylphenyl.

23. Acrylates, for example ethyl α-cyano-e, diphenylacrylate, α-cyano-e, iso-octyl diphenylacrylate, methyl α-carbomethoxycinnamate, methyl α-cyano-e-methyl p-methoxycinnamate, α-cyano-e-methyl-β butyl methoxycinnamate, methyl α-carbomethoxy p-methoxycinnamate, N- (e-carbomethoxy-e-cyanovinyl) -2-methylindoline, tetra (α-cyano-e, neopentyl e-diphenylacrylate).

24. Hindered amines, for example carbonic acid bis (1-undecyloxy-2,2,6,6-tetramethyl-4-piperidyl) ester, bis (2,2,6,6-tetramethyl4-piperidyl) sebacate, bis succinate (2.2 , 6,6-tetramethyl-4-piperidyl), bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate), bis (1-octyloxy-2,2,6,6-tetramethyl-4 sebacate) piperidyl), bis (1,2,2,6,6-pentamethyl-4-piperidyl) n-butyl-3,5-di-tert-butyl-4-hydroxybenzyl malonate, 1- (2-hydroxyethyl) -2,2,6,6-tetramethyl-4-hydroxypiperidine and succinic acid condensate, linear or cyclic N, N'-bis (2,2,6,6-tetramethyl-4-piperidyl) condensates ) hexamethylenediamine and 4-tertoctylamino-2,6-dichloro-1,3,5-triazine, tris (2,2,6,6-tetramethyl-4-piperidyl) nitrilotriacetate, tetrakis tetracarboxylate (2,2,6,6-tetramethyl- 4-piperidyl) -1,2,3,4-butane, 1,1 '- (1,2-ethanediyl) -bis (3,3,5,5-tetramethylpiperazone), 4-benzoyl2,2,6,6-tetramethylpiperidine . 4-stearyloksy-2,2,6,6-tetramethylpiperidine,

2-n-butyl-2- (2-hydroxy-3,5-di-tert-butylbenzyl) bis (1,2,2,6,6-pentamethylpiperidyl) malonate, 3-n-octyl-7,7,9 , 9-tetramethyl-1,3,8-triazaspiro [4,5] decane-2,4dione, bis (1-octyloxy-2,2,6,6-tetramethylpiperidyl) sebacate, bis (1-octyloxy-2,2) succinate, 6,6-tetramethylpiperidyl), linear or cyclic N, N'bis (2,2,6,6-tetramethyl-4-piperidyl) hexamethylenediamine and 4-morpholine-2,6-dichloro-1,3,5-triazine condensates . 2-chloro-4,6-bis (4-n-butylamino-2,2,6,6-tetramethyl) condensates opiperidyl) -1,3,5-triazine and 1,2-bis (3-aminopropylamino) ethane condensates, condensate 2-chloro-4,6-di- (4-n-butylamino-1,2,2,6,6-pentamethylpiperidyl) -1,3,5-triazine and 1,2-bis (3-aminopropylamino) ethane, 8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro [4,5] decane-2,4-dione, 3-dodecyl-1- (2,2,6,6 -tetramethyl-4-piperidyl) pyrrolidine-2,5-dione, 3-dodecyl-1- (1,2,2,6,6-pentamethyl-4-piperidyl) pyrrolidine 2,5-dione, a mixture of 4-hexadecyloxy- and 4-stearyloxy-2,2,6,6-tetramethylpiperidine, N, N'-bis (2,2,6,6-tetramethyl-4-piperidyl) hexamethylenediamine and 4-cyclohexylamino-2 condensate, 6-dichloro-1,3,5-triazine, condensate of 1,2-bis (3aminopropylamino) ethane and 2,4,6-trichloro-1,3,5-triazine, as well as 4-butylamino

2,2,6,6-tetramethylpiperidine (CAS Reg. No. [136504-96-6]); 1,6-hexanediamine and 2,4,6-trichloro-1,3,5-triazine condensate, as well as N, N-dibutylamine and 4-butylamino 2,2,6,6-tetramethylpiperidine (Reg. No. CAS [192268-64-7]); N- (2,2,6,6-tetramethyl4-piperidyl) -n-dodecylsuccinimide, N- (1,2,2,6,6-pentamethyl-4-piperidyl) -endodecylsuccinimide, 2-undecyl-7,7, 9,9-tetramethyl-1-oxa-3,8-diaza-4-oxospiro [4,5] decane, reaction product 7,7,9,9-tetramethyl-2-cycoundoundecyl-1-oxa-3,8-diaza- 4-oxospiro- [4,5] decane and epichlorohydrin, 1,1-bis (1,2,2,6,6-pentamethyl-4-piperidyloxycarbonyl) -2- (4-methoxyphenyl) ethene, N, N'-bis formyl-N, N'-bis (2,2,6,6-tetramethyl-4-piperidyl) hexamethylenediamine, 4-methoxymethylene malonic acid diester with 1,2,2,6,6-pentamethyl-4-hydroxypiperidine, poly [methylpropyl-3-oxy-4- (2,2,6,6-tetramethyl-4-piperidyl)] siloxane, reaction product copolymer maleic anhydride-α-olefm with 2,2,6,6-tetramethyl-4-aminopiperidine or 1,2,2,6,6-pentamethyl-4-aminopiperidine, 2,4-bis [N- ( 1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl) -N-butylamino] -6- (2-hydroxyethyl) amino-1,3,5-triazine, 1- (2-hydroxy-2-methylpropoxy) -4-octadecanoyloxy2,2,6,6-tetramethylpiperidine, 5- (2-ethylhexanoyl) oxymethyl-3,3,5-trimethyl-2-morpholinone, Sanduvor (Clariant; Reg. No. CAS 106917-31-1], 5- (2-ethylhexanoyl) oxymethyl-3,3,5-trimethyl-2-morpholinone, reaction product 2,4-bis [(1-cyclohexyloxy-2,2,6,6-piperidin- 4-yl) butylamino] -6-chloro-s-triazine with N, N'bis (3-aminopropyl) ethylenediamine), 1,3,5-tris (N-cyclohexyl-N- (2,2,6,6 -tetramethylpiperazin-3-one-4-yl) amino) -s-triazine, 1,3,5-tris (N-cyclohexyl-N- (1,2,2,6,6pentamethylpiperazin-3-one-4-yl) ) amino) -s-triazine.

25. Oxamides, for example 4,4'-dioctyloxyoxanilide, 2,2'-diethoxyoxanilide, 2,2'-dioctyloxy-5,5'-di-tert-butoxyanilide, 2,2'-didodecyloxy-5,5'-di-tert- butoxyanilide, 2-ethoxy-2'-ethyloxyanilide, N, N'-bis (3-dimethylaminopropyl) oxamide, 2-ethoxy-5tert-butyl-2'-ethoxyanilide and its mixture with 2-ethoxy-2'-ethyl-5 , 4'-di-tert-butoxyanilide, mixtures of o- and p-methoxy-disubstituted oxyanilides and mixtures of o- and p-ethoxy-disubstituted oxyanilides.

26. 2- (2-Hydroxyphenyl) -1,3,5-triazine, for example 2,4,6-tris (2-hydroxy-4-octyloxyphenyl) -1,3,5-triazine, 2- (2-hydroxy-4 -octyloxyphenyl) -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2- (2,4-dihydroxyphenyl) -4,6-bis (2,4-dimethylphenyl) -1, 3,5-triazine, 2,4-bis (2-hydroxy-4-propyloxyphenyl) -6- (2,4-dimethylphenyl) -1,3,5-triazine, 2- (2-hydroxy-4-octyloxyphenyl) -4 , 6-bis (4-methylphenyl) -1,3,5-triazine, 2- (2-hydroxy-4-dodecyloxyphenyl) -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine . 2- (2-hydroxy-4-tridecyloxyphenyl) -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2- [2-hydroxy-4- (2-hydroxy-3-butyloxypropoxy ) phenyl] -4,6-bis (2,4-dimethyl) 1,3,5-triazine, 2- [2-hydroxy-4- (2-hydroxy-3-octyloxypropyloxy) phenyl] -4,6-bis (2,4-dimethyl) -1,3,5-triazine, 2- [4- (dodecyloxy / tridecyloxy-2-hydroxypropoxy) 2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1, 3,5-triazine, 2- [2-hydroxy-4- (2-hydroxy-3-dodecyloxypropoxy) phenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2- (2-hydroxy-4-hexyloxy) phenyl-4,6-diphenyl-1,3,5-triazine,

2- (2-hydroxy-4-methoxyphenyl) -4,6-diphenyl-1,3,5-triazine, 2,4,6-tris [2-hydroxy4- (3-butoxy-2-hydroxypropoxy) phenyl] - 1,3,5-triazine, 2- (2-hydroxyphenyl) -4 (4-methoxyphenyl) -6-phenyl-1,3,5-triazine, 2- {2-hydroxy-4- [3- (2- 1oksy-ethylhexyl) -2-hydroxypropoxy] phenyl} -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine,

2,4-bis (4- [2-ethylhexyloxy] -2-hydroxyphenyl) -6- (4-methoxyphenyl) -1,3,5-triazine.

[0031] When used in combination with resins, the electrolyte and non-electrolyte acidifying components of the oxygen-binding composition of the invention, and any optional water-absorbing binder that can be used, are e.g. used in the form of particles or powder. Particles of at least 290 Pm or smaller are preferred because they facilitate melt processing of oxygen-binding thermoplastic resins compositions. For use with thermosetting resins for making coatings, particles smaller than the thickness of the final coating are conveniently used. The oxygen-binding composition can be used directly in the form of a powder or particles, or it can be processed, for example by melt mixing or sintering, into pellets to facilitate further handling and use. The mixture of the oxidizable metal component, electrolyte component, non-electrolyte acidifying component and optionally water absorbing binder can be added directly to the thermoplastic polymer in a mixing or melt molding operation, for example in its extrusion section, after which the molten mixture can be fed directly to the extrusion line or co-extrusion of a film or sheet, to obtain a single-layer or multi-layer film or sheet in which the amount of oxygen-binding composition is determined by the proportions in which the mixture and resin are combined in the resin feeding section of the extrusion production line. Alternatively, a mixture of the oxidizable metal component, electrolyte component, non-electrolyte acidifying component and optionally a binder can be mixed into masterbatch concentrate pellets, which can then be added to the packaging resins for further processing into extruded films or sheets, or injection molded products such as tubes, bottles, cups, trays and the like.

[0032] The degree of mixing of the oxidizable metal, electrolyte and non-electrolyte acidifying components and, if an optional binder component is used, may affect the effectiveness of the oxygen binding composition to absorb oxygen, with better mixing leading to better efficiency. The mixing effect can be most significant at low electrolyte plus non-electrolyte acidifying components to the oxidizable metal component and at very low and very high ratios of the non-electrolyte acidifying component to the electrolyte component. At below e.g. 10 parts by weight of electrolyte plus non-electrolyte acidifying components per 100 parts by weight of the metal component, or when the weight ratio of one of the electrolyte and non-electrolyte acidifying component to the other is less than about 10:90, the oxygen-binding components are preferably mixed by mixing the aqueous slurry, followed by oven-dried and ground into small particles. Below these ratios, mixing techniques suitable for higher ratios, such as intensive powder mixing, such as in a Henschel or Waring powder mixer, or lower intensity mixing techniques, such as in a roller container or drum mixer, can lead to variations in oxygen absorption , especially when the mixtures are introduced into thermoplastic resins and used in melt processing operations.

[0033] Other factors that may affect the effectiveness of the oxygen-binding composition of the invention in absorbing oxygen include the surface area of ​​articles containing the compositions, with a larger surface area typically providing better oxygen absorption efficiency. The amount of residual moisture in the water-absorbent binder, if used, can also affect performance, with a higher moisture content in the binder leading to better oxygen absorption. However, there are practical restrictions on the amount of moisture that may be present in the binder, as too much can lead to premature activation of the oxygen binder composition as well as to processing difficulties and poor aesthetic properties of the products produced. When incorporated into thermoplastic resins and used in the manufacture of articles by melt processing techniques, the nature of the resin may also have a significant impact. Thus, when the oxygen-binding composition of the invention is used with amorphous and / or oxygen-permeable polymers such as polyolefins or amorphous polyethylene terephthalate, greater oxygen uptake is observed than with compositions used with crystalline and / or oxygen barrier polymers, such as crystalline polyethylene terephthalate and EVOH.

[0034] When used with thermoplastic resins, the oxygen binding composition can be incorporated directly into the resin in amounts effective to provide the desired level of oxygen binding capacity. With such use, the preferred levels of oxygen binding agent will vary depending on the resin chosen, the configuration of the resin product and the required oxygen binding capacity of the product. The use of resins with a low inherent viscosity number, i.e. low molecular weight resins, usually allows a higher loading of the binder composition without loss of processing properties. On the contrary, smaller amounts of oxygen binding composition may facilitate the use of higher viscosity polymer materials. Preferably, at least 0.1 parts by weight of oxygen binding composition is used per 100 parts by weight of resin. Load levels of more than 200 parts per 100 parts of resin usually do not lead to an improvement in oxygen absorption and can interfere with processing and adversely affect other product properties. More preferably, load levels are used, e.g. 0.2 to 150 parts, especially 0.3 to 50 parts or 5 to 50 parts, per 100 parts resin in order to obtain good binding performance while maintaining processing properties. Load levels of 0.3 to 20 parts per 100 parts resin are particularly preferred for the production of thin films and sheets.

[0035] Preferred oxygen-binding resin compositions for the manufacture of packaging articles comprise at least one thermoplastic resin and, for example, 2 to 50 parts or 5 to 50 parts by weight of oxygen binding composition per 100 parts by weight of resin, wherein the oxygen binding composition comprises iron powder as component (I), NaCl, KCl or CaCl2 as component (II) and Na2H2P2O7 or CaH2P2O7 as component (III), optionally in combination with NaH2PO4, KH2PO4 or Ca (H2PO4) 2 as component (IIIa). More preferably, the binder composition contains e.g. 30 to 130 parts by weight of component (II) plus component (III) (= component (III) plus optionally component (IIIa)) per 10 parts by weight of iron, the weight ratio of component (II) to component (III) is e.g. 10:90 to 90:10. It may also include, for example, up to 50 parts by weight of water-absorbent binder per 100 parts by weight of resin and oxygen-binding agent. Particularly preferred compositions of this type contain polypropylene, high or low density polyethylene or linear low density polyethylene, or polyethylene terephthalate as a resin, e.g. 5 to 30 parts by weight of oxygen binding agent per 100 parts by weight of resin. Preferably e.g. 5 to 100 parts by weight of component (II) and 5 to 70 parts by weight of component (III) per 10 parts by weight of iron and e.g. 0 up to 50 parts by weight of binder per 100 parts by weight of components (I), (II), (III) and (IV).

[0036] Although the oxygen and resin binding composition may be used in a non-concentrated form for the direct production of oxygen binding sheets or films (i.e. without further diluting the resin), it is also preferred to use the oxygen and resin binding composition in the form of a concentrate or masterbatch. In this case, the ability to produce the concentrate at low material costs favors a relatively high load of oxygen binding agent, which will still allow melt mixing, for example by extrusion granulation. Accordingly, the concentrated compositions of the invention preferably contain at least e.g. 10 parts by weight of oxygen-binding composition per 100 parts by weight of resin, and more preferably 30 to 150 parts per 100 parts of resin. Suitable resins for such concentrated oxygen binding compositions include any of the thermoplastic polymer resins described herein. Low melt viscosity resins facilitate the application of a high oxygen binder load and are typically used in such low amounts in the production of finished products as alloys that typically lower molecular weight resin concentrates do not adversely affect the final properties of the product. Preferred carrier resins are polypropylene, high density, low density and linear low density polyethylene, and polyethylene terephthalate. Preferred among them are polypropylenes with a melt flow index, e.g. 1 to 40 g / 10 min, polyethylenes with a melt flow index, e.g. 1 to 20 g / 10 min, and polyethylene terephthalates with a logarithmic viscosity number, e.g. 0.6 to e.g. 1 in phenol / trichloroethane.

[0037] It is also contemplated to use different components of the oxygen-binding composition or combinations of such components to form two or more concentrates that can be combined with a thermoplastic resin to produce an oxygen-binding product. The advantage of using two or more concentrates is that the electrolyte and non-electrolyte acidifying components can be separated from the oxidizable metal until the production of finished products, thereby maintaining full or substantially full oxygen binding capacity up to actual use and allowing an oxygen binding agent less than that which might otherwise be necessary. In addition, separate concentrates allow easier preparation of various electrolyte and non-electrolytic concentrations of acidifying components and / or water-absorbing binder with oxidizable metal, and also allow manufacturers to conveniently formulate a wide range of alloy processable resin compositions whose oxygen binding capacity can be tailored to specific requirements for final use. Preferred ingredients or combinations of ingredients for use in separate concentrates are (a) an acidifying ingredient; (b) combining the oxidizable metal component with the water absorbing binder component; and (c) a combination of electrolyte and non-electrolyte acidifying components.

[0038] A particularly preferred concentrate of the components is a composition comprising Na2H2P2O7 or CaH2P2O7 and a thermoplastic resin. Such a concentrate can be added in the required amounts in melt-forming operations using a thermoplastic resin that already contains or to which other oxygen-binding components, such as the oxidizable metal or its combination with the electrolyte, will be added to achieve increased oxygen-binding capacity. Concentrates containing e.g. 10 to e.g. 150 parts by weight of component (III) per 100 parts by weight of resin, the most preferred resins being polypropylene, polyethylenes and polyethylene terephthalate.

[0039] Therefore, a further embodiment of the present invention is a master batch comprising (A) a polymer resin and (B) 30 to 150% by weight, based on the polymer resin, of the oxygen binding composition described herein.

[0040] Polymer resins that can be used to introduce the oxygen binder composition for coating inside cans by spray coating and the like are typically thermosetting resins such as epoxy resins, oleoresin, unsaturated polyester resins or phenol based materials.

[0041] Another embodiment of the present invention is an article comprising the composition described above. The article can be a film, a laminate (e.g. co-extruded multilayer film), a sheet or a rigid or flexible packaging (e.g. food packaging).

[0042] In particular, such manufactured articles comprise at least one melt-molded layer comprising the above-described oxygen binding composition. Due to the increased oxidation efficiency, they provide the oxygen-binding composition according to the invention, the layer comprising oxygen binding agent may contain relatively small amounts of oxygen binding agent. The products of the present invention are well suited for use in flexible or rigid packaging structures. In the case of the rigid sheet packaging according to the invention, the thickness of the oxygen-binding layer is preferably no more than e.g. 2500 μm, and most preferably in the range of 50 to 1300 μm. In the case of flexible packaging films according to the invention, the thickness of the layer with an oxygen binding agent is preferably not more than e.g. 250 μm and most preferably 10 to 200 gm. The packaging structures of the invention may be in the form of films or sheets, both rigid and flexible, as well as the walls or liners of cups or dishes, such as trays, cups, bowls, bottles, bags, pouches, boxes, films, bottle caps, coatings on cans and other packaging constructions. Both single-layer and multi-layer structures are considered.

[0043] The oxygen binding composition and resin of the present invention provide active barrier properties in articles made therefrom and can be melted by any suitable manufacturing technique into the walls of the packaging, and articles with excellent oxygen barrier properties that avoid the use of layers of expensive gas barrier films, such as those based on EVOH, PVDC, metallised polyolefin or polyester, albumin film, silica-coated polyolefin and polyester etc. Oxygen binding articles of the present invention also provide the added benefit of increased recyclability. A defective product or regenerate from an oxygen binding resin can easily be recycled into plastic products without adverse effects. In contrast, the recycling of EVOH or PVDC films as gas barriers may result in product deterioration due to polymer phase separation and gelation occurring between the gas barrier resin and other product resins. However, it is also contemplated to provide articles, particularly for packaging applications, with both active and passive oxygen barrier properties by using one or more layers constituting a passive gas barrier in products containing one or more layers constituting active barrier according to the invention. Accordingly, in some applications, such as food packaging for use in mass caterers and others requiring a long shelf life, the oxygen binding layer of the present invention can be used in combination with a layer or foil that is a passive gas barrier such as this based on EVOH, PVDC, metallised polyolefins or in the form of aluminum foil.

[0044] The present invention furthermore preferably relates to a packaging wall having at least one layer comprising the above-described oxygen and resin binding composition. It should be understood that any packaging product or packaging structure intended to completely enclose the product will be considered to have / have a "packaging wall," as this term is used in the description when the packaging product includes a wall or part thereof that is or is intended to be placed between the packaged product and the atmosphere outside the packaging and the wall or part thereof includes at least one layer, which includes the oxygen binding composition of the present invention. Therefore, bowls, bags, liners, trays, cups, cartons, pouches, boxes, bottles and other dishes or containers that are intended to be sealed tightly after being filled with the product concerned are covered by the term 'packaging wall' if the oxygen-binding composition according to the invention, it is present in any wall of such a vessel (or in a part of such a wall) which is placed between the packaged product and the atmosphere outside the packaging, when the vessel is closed or sealed. One example is when the oxygen binder composition of the invention is formed as a continuous thermoplastic layer enclosing or substantially enclosing the product, or being inserted between one or more of such layers. Another example of the wall of the package of the invention is a single-layer or multi-layer film containing the oxygen-binding composition of the invention, used as a cap insert in a beverage bottle (e.g. with beer, wine, fruit juice, etc.) or as packaging material.

[0045] An attractive active barrier layer is generally considered to be one in which the kinetics of the oxidation reaction is fast enough and the layer is thick enough that most of the oxygen permeating the layer reacts without allowing a substantial amount of oxygen to pass through the layer. Furthermore, it is important that this "steady state" lasts for a period appropriate to the end use requirements before the oxygen-binding layer is depleted. The present invention provides such a steady state and excellent stability of the oxygen binding agent at economically economical layer thicknesses, for example, less than e.g. 2500 μm for rigid packaging sheets and less than e.g. 250 μm for flexible films. With the rigid sheet packaging of the present invention, an attractive oxygen-binding layer in the range of 250 to 750 Pm can be obtained, while with flexible packaging films, 20 to 200 Pm thick layers are attractive. Such layers can work effectively with only e.g. 2 to 10% by weight of the oxygen binding composition based on the weight of the oxygen binding layer.

[0046] In the production of the packaging structures of the invention, it should be noted that the oxygen-binding resin composition of the invention is substantially inactive with respect to the chemical reaction with oxygen as long as the water activity in the composition is not sufficient. In contrast, the composition becomes active in binding oxygen when the water activity reaches a certain level. The water activity is such that before use, the packaging products of the invention can remain substantially inactive in relatively dry environments without special measures to maintain low humidity levels. However, when the packaging is used, most products will have sufficient humidity to activate the oxygen binding composition introduced into the walls of the packaging article.

[0047] To form the wall of the packaging according to the invention, an oxygen-binding resin composition or an oxygen-binding composition or components thereof or a concentrate thereof is used, mixed or otherwise combined with a suitable packaging resin, after which the resulting resin composition is processed into sheets, foils or other shaped structures. Extrusion, coextrusion, blow molding, injection molding or any other technique for making sheet, film or melt polymer generally may be used. Sheets and films obtained from the oxygen-binding composition can be further processed, e.g. by coating or laminating to produce multilayer sheets or films, followed by shaping, such as thermoforming or other forming operations, into desirable packaging walls in which at least one layer contains an oxygen binding agent. Such packaging walls can be further processed or shaped, if desired or necessary, to obtain a variety of packaging products with an active barrier for final use. The present invention reduces the cost of such barrier products compared to conventional products that are given barrier properties by using passive barrier films.

[0048] As a preferred manufactured article, the invention provides a packaging article comprising a wall, or a connection of mutually connected walls, in which the wall or wall connection defines a lockable space containing the product, and in which the wall or wall connection comprises at least one wall section having a layer an oxygen binding comprising (i) a thermoplastic elastomer (ii) an oxidizable metal preferably being at least one component selected from the group consisting of Al, Mg, Zn, Cu, Fe, Sn, Co and Mn, and most preferably 0.1 to 100 parts of iron per 100 parts by weight of resin; (iii) an electrolyte component and a solid, non-electrolyte acidifying component that has a pH below 7 in the presence of water, e.g. from 5 to about 150 parts by weight of such components per 10 parts by weight of iron, preferably present, with a weight ratio of non-electrolyte acidifying component to electrolyte component preferably of about 5/95 to about 95/5; a polymer resin other than component (i) and, optionally, a water absorbing binder.

[0049] A particularly attractive packaging structure according to the invention is a packaging wall comprising a plurality of thermoplastic layers glued together in bonded laminar contact, wherein at least one oxygen-binding layer is glued to one or more other layers that may or may not contain oxygen binding composition. Particularly preferably, although it is not required, the thermoplastic resin constituting the main component can be the same in each of the layers of the packaging wall, so that a "pseudo-monolayer" is obtained. This design can easily be recycled.

[0050] An example of a packaging product using the wall of the packaging described above is a double-layer or three-layer double oven-warming tray made of crystalline polyethylene terephthalate ("C-PET") suitable for packaging ready-to-heat disposable meals. In a three-layer structure, a 250 to 500 μm thick oxygen binding layer is sandwiched between two 70 to 250 μm thick C-PET layers that do not bind oxygen. The resulting tray is considered "pseudo-monolayer" because, for practical recycling purposes, the tray contains one thermoplastic resin, or C-PET. The waste from such a pseudomonelayer tray can easily be recycled, because the oxygen binding agent in the middle layer does not reduce the possibility of recycling. In the C-PET tray, the outer layer that does not bind oxygen provides additional protection against the passage of oxygen by slowing oxygen, so that it reaches the middle layer at a relatively low speed and most of the incoming oxygen can be absorbed by the middle layer without penetrating it. Any inner layer that does not bind oxygen acts as an additional oxygen barrier, but at the same time is permeable so that the oxygen inside the tray can pass into the middle oxygen-binding layer. The use of a three-layer structure is not necessary. For example, in the above construction, the inner C-PET layer can be eliminated. The tray made of a single oxygen-binding layer is also an attractive design.

[0051] The pseudo-monolayer concept can also be applied to a wide range of polymeric packaging materials to achieve the same recycling benefits observed with a C-PET pseudo-monolayer tray. For example, packaging made of polypropylene or polyethylene may be made of a multilayered packaging wall (e.g., foil) comprising the oxygen binding composition of the present invention. In a two-layer construction, the oxygen-binding layer may be an inner layer, with a polymer layer that does not bind oxygen, outside to provide additional barrier properties. A sandwich construction is also possible in which a layer of resin containing an oxygen binding agent, such as polyethylene, is sandwiched between two polyethylene layers that do not bind oxygen. Alternatively, polypropylene, polystyrene or other suitable resin can be used in all layers.

[0052] Various recycling modes can be used to make the packaging sheets and films of the invention. For example, in the production of a multilayer sheet or film, comprising a binding and non-binding oxygen layer, the waste regenerate of the entire multilayer sheet may be recycled for reuse in the oxygen binding sheet or film layer. The multilayer sheet can also be recycled for all layers of the sheet.

[0053] The walls of the package and packaging products of the present invention may contain one or more layers that are foamed. Any suitable polymer foaming technique may be used, such as bead foaming or extrusion foaming. For example, a packaging article can be obtained in which a foamed resin layer comprising, for example, foamed polystyrene, foamed polyester, foamed polypropylene, foamed polyethylene, or mixtures thereof, can be glued to a solid resin layer containing the oxygen binding composition of the present invention. Alternatively, the foamed layer may comprise an oxygen-binding composition, or both the foamed and non-foamed layer may include an oxygen-binding composition. The thickness of such foamed layers is usually dictated more by requirements for mechanical properties, e.g., rigidity and impact strength of the foam layer, than requirements for oxygen binding.

[0054] The advantage of packaging constructions such as those described above may be the possibility of eliminating expensive passive barrier films. However, when an extremely long life or increased oxygen protection is required or desired, a package wall according to the invention can be made comprising one or more layers of EVOH, nylon or PVDC, and even of metallised polyolefin, metallized polyester or aluminum foil. Another type of passive layer that can be reinforced by the oxygen-binding resin layer of the present invention is a silica-coated polyester or a silica-coated polyolefin. In the case where the multilayer wall of the package according to the invention comprises layers of different polymer compositions, it may be advantageous to use adhesive layers such as those based on ethylene-vinyl acetate or maleinised polyethylene or polypropylene, whereby the oxygen binder according to the present invention the invention can be incorporated into such adhesive layers. The oxygen-binding composition of the present invention can also be prepared using a gas barrier resin, such as EVOH, nylon or PVDC polymer, to provide films with both active and passive barrier properties.

[0055] Although the purpose of one embodiment of the invention is to introduce the oxygen binding composition directly into the wall of the container, the oxygen binding composition can also be used in packets as a separate cartridge in the packaged product when the only purpose is to absorb oxygen in the gas phase over the product.

[0056] The primary use of oxygen binding resin, packaging walls and packaging products according to the invention is the packaging of perishable food. For example, packaging products utilizing the invention can be used to package milk, yogurt, ice cream, cheese; braised meat and soups; meat products such as frankfurters, cold meats, chicken, dried beef; disposable meals and starters ready to heat; homemade pasta and spaghetti sauce; spices such as barbecue sauce, ketchup, mustard and mayonnaise; drinks such as fruit juice, wine and beer; dried fruit and vegetables; breakfast cereal; bakery products such as bread, crackers, cakes, cookies and muffins; snacks such as sweets, potato chips, cheese stuffed snacks; peanut butter or a combination of peanut butter and jelly, jams and jelly; dried and fresh spices; and pet and other food; etc. It is intended that the above enumeration is not intended to limit the scope of the possible applications of the invention. In general, it can be said that the invention can be used to increase barrier properties in packaging materials for any type of product that can degrade in the presence of oxygen.

[0057] Still other uses of the oxygen binding compositions of the present invention include the inner coatings of metal cans, especially for oxygen sensitive food products such as tomato based materials, baby food and the like. Typically, the oxygen-binding composition may be combined with polymer resins such as thermosetting epoxy resin, oleoresin, unsaturated polyester resins or phenol-based materials, the material being applied to the metal can by methods such as roller coating or spray coating. [0058] Accordingly, a further embodiment of the invention is the use of an oxygen-binding mixture comprising components (I) to (IV) as defined above in food packaging. [0059] A general overview of the different possible uses of the oxygen binding composition is exemplified in US-A-5,744,056, US-A-5,885,481, US-A-6,369,148 and US-A-6,586,514

[0060] The following examples further illustrate the invention. All percentages and parts are by weight unless otherwise stated.

Comparative sample 1:

[0061] NaCl, Na2H2P2O7 and NaH2PO4 are mixed with low density polyethylene (Riblene

FF29^®), so that the NaCl / Na2H2P2O7 / NaH2PO4 weight ratios are 1 / 0.92 / 0.08 and the final NaCl concentration is 3.5% by weight. Fe particles are added at different concentrations (by weight) of 7.0% using conventional electrolytic iron powder, below 325 mesh (<44 μm). The compositions are prepared using an OMC pilot twin screw extruder (model EBV 19/25, with a screw diameter 19 mm and ratio 1:25), and films with a thickness of 50 microns are made using a Formac Blow Extruder blow molding machine (model Lab25 , with a screw with a diameter of 22 mm and a ratio of 1:25).

Comparative sample 2:

[0062] NaCl and Na2H2P2O7 are mixed with polypropylene (RD208CF^®) so that the NaCl / Na2H2P2O7 weight ratios are 1 / 0.50 and the final NaCl concentration is 7.0% by weight. Fe particles are added at different concentrations (by weight) of 7.0% using conventional electrolytic iron powder, below 325 mesh (<44 μm). The compositions are prepared using an OMC pilot twin screw extruder (model EBV 19/25, with a screw diameter of 19 mm and a ratio of 1:25), and films with a thickness of 100 microns are made using a Collin Cast Flat die extrusion equipment -die Extruder model 30 x 25 L / D (30 mm screw diameter, diameter to length ratio 1:25). Sample according to the invention 1:

[0063] NaCl, Na2H2P2O7, NaH2PO4 and copolyester elastomer (Arnitel VT3104^®) mixed with low density polyethylene (Riblene FF29^®), so that the NaCl / Na2H2P2O7 / NaH2PO4 / copolyester elastomer weight ratios are 1 / 0.92 / 0.08 / 2.8 and the final NaCl concentration is 3.5% by weight. Fe particles are added at different concentrations (by weight) of 7.0% using conventional electrolytic iron powder, below 325 mesh (<44 μm). Samples are prepared as described in Comparative Sample 1.

Sample according to the invention 2:

[0064] NaCl, Na2H2P2O7, NaH2PO4 and copolyester elastomer (Arnitel VT3108^®) mixed with low density polyethylene (Riblene FF29^®), so that the NaCl / Na2H2P2O7 / NaH2PO4 / copolyester elastomer weight ratios are 1 / 0.92 / 0.08 / 2.8 and the final NaCl concentration is 3.5% by weight. Fe particles are added at different concentrations (by weight) of 7.0% using conventional electrolytic iron powder, below 325 mesh (<44 μm). Samples are prepared as described in Comparative Sample 1.

Sample according to the invention 3:

[0065] NaCl, Na2H2P2O7, NaH2PO4 and copolyester elastomer (Arnitel PM381^®) mixed with low density polyethylene (Riblene FF29^®), so that the NaCl / Na2H2P2O7 / NaH2PO4 / copolyester elastomer weight ratios are 1 / 0.92 / 0.08 / 2.8 and the final NaCl concentration is 3.5% by weight. Fe particles are added at different concentrations (by weight) of 7.0% using conventional electrolytic iron powder, below 325 mesh (<44 μm). Samples are prepared as described in Comparative Sample 1.

Sample according to the invention 4:

[0066] NaCl, Na2H2P2O7, NaH2PO4 and copolyester elastomer (Arnitel PM381^®) mixed with low density polyethylene (Riblene FF29^®), so that the NaCl / Na2H2P2O / NaH2PO4 / copolyester elastomer weight ratios are 1 / 0.92 / 0.08 / 2.04 and the final concentration of NaCl is 2.45% by weight. Fe particles are added at varying concentrations (4.9 wt.%) Using standard electrolytic iron powder, below 325 mesh (<44 gm). Samples are prepared as described in Comparative Sample 1.

Sample according to the invention 5:

[0067] NaCl, Na2H2P2O7, NaH2PO4 and copolyester elastomer (Arnitel PM381^®) mixed with low density polyethylene, Riblene FF29^®, so that the NaCl / Na2H2P2O7 / NaH2PO4 / copolyester elastomer weight ratios are 1 / 0.92 / 0.08 / 1.23 and the final concentration of NaCl is 2.45% by weight. Fe particles are added at varying concentrations (4.9 wt.%) Using standard electrolytic iron powder, below 325 mesh (<44 μm). Samples are prepared as described in Comparative Sample 1.

Sample according to the invention 6:

[0068] NaCl, Na2H2P2O7 and NaH2PO4 are mixed with a copolyester elastomer (Arnitel VT3104^®), so that the NaCl / Na2H2P2O7 / NaH2PO4 weight ratios are 1 / 0.92 / 0.08 and the final NaCl concentration is 3.5% by weight. Fe particles are added at different concentrations (by weight) of 7.0% using conventional electrolytic iron powder, below 325 mesh (<44 μm). Samples are prepared as described in Comparative Sample 1.

Sample according to the invention 7:

[0069] NaCl, Na2H2P2O7 and NaH2PO4 are mixed with a copolyester elastomer (Arnitel VT3108^®), so that the NaCl / Na2H2P2O7 / NaH2PO4 weight ratios are 1 / 0.92 / 0.08 and the final NaCl concentration is 3.5% by weight. Fe particles are added at different concentrations (by weight) of 7.0% using conventional electrolytic iron powder, below 325 mesh (<44 μm). Samples are prepared as described in Comparative Sample 1.

Sample according to the invention 8:

[0070] NaCl, Na2H2P2O7 and NaH2PO4 are mixed with a copolyester elastomer (Arnitel PM381^®), so that the NaCl / Na2H2P2O7 / NaH2PO4 weight ratios are 1 / 0.92 / 0.08 and the final NaCl concentration is 3.5% by weight. Fe particles are added at different concentrations (by weight) of 7.0% using conventional electrolytic iron powder, below 325 mesh (<44 μm). Samples are prepared as described in Comparative Sample 1.

[0071] Several portions of each film sample are then exposed to air (20.7% O2) in sealed 500 ml flasks equipped with a septum to allow aspiration of the internal atmosphere sample with a syringe for analysis at several intervals in the presence of 15 ml of water contained in the vial inside the flasks. Oxygen concentration measurements are made using a gas phase analyzer over Mocon Pac Check 450 samples over 28 days. Actual iron concentrations in the samples tested are finally measured with an ICP -OES (Inductively Coupled Plasma - Optical Emission Spectrometer), Perkin Elmer Optima Series 4200DV). The results in ml O2 / g iron are given in Table 1 as averages of five different measurements for each film sample.

Table 1: Average oxygen binding agent activity (ml O2 / g iron) for seven different LDPE films, measured after 28 days.

<td></td><td>ml O₂/ g iron after 28 days *</td>

<td>Comparative sample 1</td><td> 38</td>

<td>Sample according to the invention 1</td><td> 49</td>

<td>Sample according to the invention 2</td><td> 79</td>

<td>Sample according to the invention 3</td><td> 83</td>

<td>Sample according to the invention 4</td><td> 147</td>

<td>Sample according to the invention 5</td><td> 163</td>

<td>Sample according to the invention 6</td><td> 130</td>

<td>Sample according to the invention 7</td><td> 145</td>

<td>Sample according to the invention 8</td><td> 93</td>

[0072] Table 1 clearly shows that the activity of the oxygen binding agent for samples 1 to 8 according to the invention is greater than the activity of the iron particles as oxygen binding agent for Comparative Sample 1.

Sample according to the invention 9:

[0073] NaCl, Na2H2P2O7 and copolyester elastomer (Arnitel VT3104^®) mixed with polypropylene (RD208CF^®), so that the weight ratios NaCl / Na2H2P2O7 / copolyester elastomer are 1 / 0.50 / 1.4 and the final concentration of NaCl is 7.0% by weight. Fe particles are added at different concentrations (by weight) of 7.0% using conventional electrolytic iron powder, below 325 mesh (&lt;44 gm). Samples are prepared as described in comparative sample 2.

Sample according to the invention 10:

[0074] NaCl, Na2H2P2O7 and copolyester elastomer (Arnitel VT3108^®) mixed with polypropylene (RD208CF^®), so that the weight ratios NaCl / Na2H2P2O7 / copolyester elastomer are 1 / 0.50 / 1.4 and the final concentration of NaCl is 7.0% by weight. Fe particles are added at different concentrations (by weight) of 7.0% using conventional electrolytic iron powder, below 325 mesh (&lt;44 gm). Samples are prepared as described in comparative sample 2.

Sample according to the invention 11:

[0075] NaCl, Na2H2P2O7 and copolyester elastomer (Arnitel PM381^®) mixed with polypropylene (RD208CF^®), so that the NaCl / Na2H2P2O7 / copolyester elastomer weight ratios are 1 / 0.50 / 1.4 and the final NaCl concentration is 7.0% by weight. Fe particles are added at varying concentrations (by weight) of 7.0% using conventional electrolytic iron powder, below 325 mesh (&lt;44 Lim). Samples are prepared as described in comparative sample 2.

Sample according to the invention 12:

[0076] NaCl, Na2H2P2O7 and copolyester elastomer (Arnitel PM381^®) mixed with polypropylene (RD208CF^®), so that the weight ratio NaCl / Na2H2P2O7 / copolyester elastomer is 1 / 0.50 / 0.714 and the final concentration of NaCl is 7.0% by weight. Fe particles are added at different concentrations (by weight) of 7.0% using conventional electrolytic iron powder, below 325 mesh (&lt;44 μm). Samples are prepared as described in comparative sample 2.

[0077] Several portions of each film sample are then exposed to air (20.7% O2) in sealed 500 ml flasks equipped with a septum to allow aspiration of the internal atmosphere sample for syringe analysis at several intervals in the presence of 15 ml of water contained in the vial inside the flasks. Oxygen concentration measurements are made using a gas phase analyzer on Mocon Pac Check 450 samples over 28 days. Actual iron concentrations in the samples tested are finally measured with an ICP -OES (Inductively Coupled Plasma - Optical Emission Spectrometer), Perkin Elmer Optima Series 4200DV). The results in ml O2 / g iron are given in Table 2 as averages of five different measurements for each film sample.

Table 2: Average activity of the oxygen binding agent (ml O2 / g iron) for four different PP films, measured after 28 days.

<td></td><td>ml O₂/ g iron after 28 days *</td>

<td>Comparative sample 2</td><td> 51</td>

<td>Sample according to the invention 9</td><td> 73</td>

<td>Sample according to the invention 10</td><td> 100</td>

<td>Sample according to the invention 11</td><td> 104</td>

<td>Sample according to the invention 12</td><td> 87</td>

[0078] Table 2 clearly shows that the activity of oxygen binding agent for samples 9 to 12 according to the invention is greater than the activity of iron particles as oxygen binding agent for Comparative Sample 2.

The amount of oxygen absorbed by the tested samples is determined by changing the concentration of oxygen in the gas phase over the samples in a sealed glass container. The volume of the gas phase over the samples in the test container is about 500 ml, and the atmospheric air it contains is such that about 100 ml of oxygen was available for reaction with iron particles. In all examples, the percentage of oxygen binding component was by weight relative to the total weight of the film composition.

Detailed description of the method for determining oxygen absorption:

[0079] From the extruded films, 1-2 cm strips are cut and discarded from the edges. The thickness of the film is measured and 4.00 grams of film (± 0.01 g) are weighed. The foil is folded into a harmonica and placed in a clean, sealed glass container of 500 ml. A vial containing 15 ml of deionized water is added to obtain relative humidity inside the glass container

100%.

The oxygen content of the ambient air on day 0 (i.e. equal to the initial oxygen content in a sealed glass container) is tested and recorded.

Glass containers with tested films and water vials are kept at 22 ° C (essentially at room temperature) for 28 days.

Oxygen content in sealed glass containers is tested and recorded using a Mocon oxygen analyzer on day 0 and day 28.

[0080] Based on the measured concentration of oxygen remaining in the sealed glass container, the volume of oxygen absorbed per gram of oxygen binding agent can be calculated using the following formula.

Absorbed oxygen (ml / g) = {(% O2) and - (% O2) f} * 0.01 * Vj / (WF * WS / WB) where:

(% O2) and Initial oxygen concentration in a sealed glass container (%) (% O2) f Oxygen concentration in a sealed glass container on the day of the test (%) 0.01: Conversion factor

Vj: Volume of free air in a sealed glass container (ml) (total volume of the sealed glass container minus the volume occupied by the vial and film, usually 440 ml)

WF: Weight of foil placed in a glass container (usually 4.0 g)

WS: Mass of oxygen binder used to make the mixture (g)

WB: Total mixture mass (g)