TWI746895B - Oxygen scavenging formulation and method of scavenging oxygen - Google Patents

Abstract

An oxygen scavenging formulation comprising an oxidizable polymer resin, a transition metal catalyst, and a photosensitizer selected from one or more carotenoids is provided. The oxygen scavenging formulation does not need an additional triggering agent, or heating or light irradiation to trigger an oxygen scavenging function. A method of reducing oxygen atmosphere in a packaging article is also provided.

Description

Deoxygenation formulation and deoxygenation method

The present invention relates to a deoxygenation formulation whose deoxygenation function does not need to be triggered by an additional trigger, or by heating or light radiation. Specifically, the formulation includes an oxidizable polymer resin, a transition metal catalyst, and a photosensitizer selected from one or more carotenoids.

The deoxygenation packaging technology has been widely used in the food packaging industry. Most oxygen-sensitive products degrade in the presence of oxygen, including food products such as meat and cheese, smoked and processed luncheon meats, and non-food products such as electronic components, pharmaceuticals, and medical products. Limiting exposure to oxygen provides a means to maintain and enhance the quality and shelf life of the packaged product (in particular, in the food industry). Therefore, removing oxygen from the encapsulated product and creating a barrier layer that prevents oxygen permeation during storage is a crucial goal for encapsulation technology.

Several techniques have been developed to limit the exposure of sensitive packaging materials to oxygen. Such technologies include the use of barrier materials with lower oxygen permeability as part of the packaging; including items other than packaging materials that can consume oxygen (through the use of pouches with materials capable of reacting with oxygen); and packaging (for example, The modified atmosphere packaging (MAP) and vacuum packaging) produce a low-oxygen environment). Although each of the above technologies has its own status in the industry, it is fully recognized that the inclusion of oxygen scavengers as part of the encapsulated product is one of the most desirable means to limit oxygen exposure.

In the late 1970s, Ageless®, an oxygen-free agent developed by Japan's Mitsubishi Gas Chemical Company, Inc., was introduced into commercial applications in the form of deoxygenating pouches, label stickers or components of food packaging materials themselves. The principle of deoxygenation relies on the reaction between the deoxidizer and oxygen. Among the previously developed scavengers, it is possible to distinguish between iron-based, sulfite-based, ascorbate-based and enzyme-based systems, and oxidizable polyamides and ethylenically unsaturated hydrocarbons. These oxygen scavengers are preferably effective in reducing the oxygen content in the package to less than 0.01% of the air. Compared with MAP, such as vacuum packaging or nitrogen filling technology, which can only reduce the oxygen content to 0.3-3%, the oxygen removal effect is more obvious. However, water, high temperature, or light, for example, is required to trigger the oxygen scavenger to activate the oxidation reaction. Iron-based scavengers are based on the oxidation of metallic iron to iron (II) hydroxide and iron (III) hydroxide. Except for certain accelerators that have an accelerating effect, the reaction requires moisture in order to start the purge process. This creates a trigger mechanism that makes purposeful activation possible. However, this type of scavenger is only suitable for products with high moisture content. In addition, when such powdered scavengers are used for polymer flakes, the general disadvantages are that they reduce transparency and deteriorate the mechanical properties of these flakes. In the absence of a triggering agent or triggering process, the deoxygenation effect cannot be triggered. In another aspect, the trigger can be directly added to the packaging material to produce a self-triggered oxygen scavenging packaging material.

Conventionally, the triggering process requires high temperature or ultraviolet light to provide a specific amount of energy to activate the oxygen scavenging function of the double bond-containing polymer. For example, US 5911910 A discloses that an encapsulation film produced by an oxidizable organic compound (such as an unsubstituted or substituted ethylenically unsaturated hydrocarbon polymer) is exposed to ^{ultraviolet light with an intensity greater than 100 mJ/cm 2} and in the cavity After heating the chamber to a temperature of 65 to 80°F, it can trigger the deoxygenation function of oxidizable organic compounds. US 6610215 B discloses a heat-activated oxygen scavenging formulation, which contains an oxidizable organic compound, such as a cycloolefin compound, such as ethylene methyl cyclohexene copolymer or ethylene methyl acrylate/cyclohexen methacrylate terpolymer And transition metal catalysts. The oxygen scavenging formulation can be used in bags and films with a single-layer or multilayer structure. The deoxygenation function can be triggered by heating the deoxygenation formulation to a temperature of 75 to 300°C for more than 60 minutes.

US 7468144 B2 discloses a process for thermally triggering oxygen scavenging formulations by using peroxides (such as hydrogen peroxide). The oxygen scavenging formulations include oxidizable organic compounds and transition metals. The process includes wetting the surface of the packaged product made from the deoxygenation formulation with a 2% hydrogen peroxide solution; then, applying 70°C hot air to remove the excess hydrogen peroxide solution; and finally exposing the product to ultraviolet light to trigger Deaeration function. The results show that pretreatment of encapsulated products with peroxide can enhance the oxygen scavenging effect caused by oxidizable organic compounds.

Triggers have also been extensively studied in this field. For example, US 6139770A discloses that the trigger can be a photoinitiator, the photoinitiator includes a benzophenone derivative containing at least two benzophenone moieties, such as trityltriphenylbenzene and substituted The oxygen scavenging formulation containing the photoinitiator can be triggered by ultraviolet or visible light, electron beam or heat having a wavelength ranging from about 200 nm to about 750 nm To activate. US 7153891 B2 discloses that the trigger can be a photoinitiator comprising one or more materials selected from the group consisting of: isopropylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone And 1-chloro-4-propoxythioxanthone, and oxygen scavenger formulations containing this type of photoinitiator can be triggered by the actinic radiation dose of a germicidal lamp with a dominant emission wavelength of 254 nanometers.

Oxygen scavengers based on polymers containing typical double bonds need to be triggered by exposure to light or heating to high temperatures. However, since the heating process not only takes a lot of time and is also limited to the specific processing temperature range of the packaging material, it is not particularly suitable for coated, printed or heat-sealed multilayer packaging films. On the other hand, for radiation-triggered oxygen scavengers, food processing plants will need to purchase additional high-intensity UV radiation equipment, which will incur additional capital expenditure.

Therefore, although various methods have been developed to trigger the deoxygenation function of packaged products, there is still a need to improve the deoxygenation formulation and the packaging material using the deoxygenation formulation.

The present invention provides an improved deoxygenation formulation in which the deoxygenation function does not require additional triggers or is triggered by heat or light radiation, and a product made from the deoxygenation formulation.

Therefore, one aspect of the present invention relates to an oxygen-scavenging formulation, which comprises an oxidizable polymer resin, a transition metal catalyst, and a sensitizer selected from one or more carotenoids.

Another aspect of the present invention relates to a method of reducing the oxygen atmosphere in a packaged product, which comprises providing an oxygen scavenging formulation to the packaged product to allow the scavenging formulation to contact oxygen and reduce the oxygen atmosphere in the packaged product, wherein The oxygen scavenging formulation includes an oxidizable polymer resin, a transition metal catalyst, and a photosensitizer selected from one or more carotenoids.

Another aspect of the present invention relates to a method for reducing the oxygen atmosphere in an encapsulated product, which comprises the following steps: a) exposing an oxygen scavenging formulation to UV radiation to trigger oxygen removal, wherein the oxygen scavenging formulation includes an oxidizable polymer Sensitizer selected from one or more carotenoids; and b) providing the triggered oxygen scavenging formulation to the inside of the packaged product to allow the scavenging formulation to contact oxygen and reduce the amount of oxygen in the packaged product. Oxygen atmosphere.

Another aspect of the present invention relates to a method for reducing the oxygen atmosphere in an encapsulated product, which comprises the following steps: a) exposing a multilayer encapsulation film containing an oxygen-scavenging film to UV radiation to trigger oxygen removal, wherein the oxygen-scavenging film is composed of An oxygen scavenging formulation comprising an oxidizable polymer resin, a transition metal catalyst, and a sensitizer selected from one or more carotenoids; and b) sealing the multilayer packaging film to form an encapsulated product to allow the oxygen scavenging formulation to contact oxygen and Reduce the oxygen atmosphere in the packaged products.

The present invention can be understood more easily with reference to the detailed description of various embodiments, examples and tables with related descriptions of the present invention below. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs. It will be further understood that terms such as those defined in commonly used dictionaries should be interpreted as consistent with their meaning in the context of related technologies, and will not be interpreted in an idealized or excessively formal sense, unless clearly defined herein. It should also be understood that the terms used herein are only for the purpose of describing specific embodiments and are not intended to be limiting.

It must be noted that unless the context clearly dictates otherwise, as used herein, the singular forms "a/an" and "the" include plural indicators. Therefore, unless the context requires otherwise, singular terms shall include pluralities and plural terms shall include the singular.

The word "or" in a list with reference to two or more items covers all the following explanations of the word group: any one of the items in the list, all the items in the list, and any combination of the items in the list.

Generally, ranges are expressed herein as from "about" one specific value and/or to "about" another specific value. When expressing such ranges, an embodiment includes the range from one specific value and/or to another specific value. Similarly, when values are expressed as approximations by using the word "about," it should be understood that the particular value forms another embodiment. It will be further understood that the endpoint of each of the ranges is meaningful relative to and independent of the other endpoint. As used herein, the term "about" means ±20%, preferably ±10%, and even more preferably ±5%.

Unless the context clearly requires otherwise, throughout the specification and the scope of the patent application, the words "comprise/comprising" and the like should be interpreted in an inclusive meaning rather than an exclusive or exhaustive meaning; in other words, "including (but Not limited to)” to explain the meaning. In addition, when used in this application, the words "in this article", "above", "below" and words with similar meanings shall refer to this application as a whole rather than any specific part of this application.

"Reduced oxygen atmosphere" or "reduced oxygen atmosphere" means that the partial pressure of oxygen in the packaged product is reduced compared to the partial pressure of oxygen in the earth's atmosphere at the standard temperature and pressure at sea level. The reduced oxygen atmosphere package may include a modified atmosphere package in which the partial pressure of oxygen is less than that of the earth's atmosphere at the standard temperature and pressure at sea level.

According to the present invention, "packaged product" refers to an article of manufacture, which can be in the form of a net, such as a single-layer or multilayer film, a single-layer or multilayer sheet; containers, such as bags, shrink bags, pouches; shells, trays, trays with lids, Package trays, shape shrink packaging, vacuum surface packaging, flow-type cladding packaging, thermoforming packaging, packaging inserts, or combinations thereof. Those skilled in the art will understand that, according to the present invention, the encapsulated product may include flexible, rigid or semi-rigid materials and may be heat-shrinkable or heat-non-shrinkable, or directional or non-directional.

As used herein, "intermediate layer" refers to a layer disposed between and in contact with at least two other layers.

As used herein, "outer layer" is a relative term and does not have to be a surface layer.

The term "outer layer" refers to the layer containing the outermost surface of the film or product. For example, the outer layer may form the outer surface of the package that overlaps the outer layer of the other package during heat sealing of the two packages.

The term "inner layer" refers to the layer containing the innermost surface of the film or product. For example, the inner layer forms the inner surface of the enclosed package. The inner layer can be a food contact layer and/or a sealant layer.

The term "adhesive layer" refers to a layer or material that is placed on one or more layers to facilitate adhesion of one layer to another surface. Preferably, the adhesive layer is disposed between the two layers of the multilayer film to keep the two layers in position relative to each other and prevent undesired delamination. Unless otherwise specified, the adhesive layer may have any suitable composition that provides the desired degree of adhesion on one or more surfaces in contact with the adhesive layer material. Optionally, the adhesive layer placed between the first layer and the second layer in the multilayer film may include components of both the first layer and the second layer to help the adhesive layer adhere to the first layer and the second layer at the same time Both of the second layer, to the opposite side of the adhesive layer.

As used herein, the terms "seal layer/sealing layer", "heat sealing layer" and "sealant layer" refer to the outer film layer, or involve sealing a film to itself, to the same film, or another The other film layer of the film and/or the layer of another product (such as a disc) that is not a film. Generally speaking, the sealant layer is an inner layer of any suitable thickness that provides sealing of the film to itself or another layer. Regarding packages with only fin seals, the term "sealant layer" generally refers to the inner surface film layer of the package as opposed to surrounding seals. The inner layer can often also serve as the food contact layer in food packaging.

"Food contact layer" refers to the part of the packaging material that contacts the packaging food product.

In one embodiment, the present invention provides an oxygen-scavenging formulation comprising an oxidizable polymer resin, a transition metal catalyst, and a photosensitizer selected from one or more carotenoids.

In a preferred embodiment of the present invention, the oxidizable polymer resin may contain an olefin compound containing a double bond, such as (i) Homopolymers and copolymers of olefin monomers, such as ethylene and propylene, and higher 1-olefins, such as 1-butene, 1-hexene, 1-hexene, or 1-octene. Preferably polyethylene LDPE and LLDPE, HDPE and polypropylene; (ii) Homopolymers and copolymers of olefin monomers with diene monomers, such as butadiene, isoprene, and cyclic olefins, such as norbornene; or (iii) Copolymers of one or more 1-olefins and/or diolefins with carbon monoxide and/or other vinyl monomers, including (but not limited to) acrylic acid and its corresponding acrylate, methacrylic acid and its corresponding ester , Vinyl acetate, vinyl alcohol, vinyl ketone, styrene, maleic anhydride and vinyl chloride. More preferably, the oxidizable polymer resin used in the present invention may be polybutadiene or styrene-butadiene copolymer.

A transition metal catalyst is added to the oxygen scavenging formulation to facilitate the oxidation reaction of the oxidizable polymer resin. The transition metal catalyst turns the formulation into an "activated" deoxygenation formulation. The transition metal catalyst may be a salt including a metal selected from the first, second, or third transition series of the periodic table. The metal is preferably one of the elements in the Rh, Ru, or Sc to Zn series (ie, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn), more preferably Mn, Fe At least one of, Co, Ni and Cu, and the best is Co. Suitable anions for such salts include (but are not limited to) chlorine, acetate, caprylate, oleate, stearate, palmitate, 2-ethylhexanoate, neocaprate, decanoate Salt, neodecanoate and naphthenate. Examples of the use of such salts are given in US 3,840,512 and US 4,101,720, such as cobalt neocaprate.

In one embodiment of the present invention, carotenoids can be used as photosensitizers to trigger the deoxygenation function. Carotenoids are preferably selected from the group consisting of lycopene, zeaxanthine, retinol, cantaxanthine, α-carotene, β-carotene, γ-carotene and δ -Carotene, astaxin, astaxanthin, chrysanthemaxanthin, torularhodin, violaxanthin, capsanthin, capsorubin ), riboflavin (riboflavin), lutein (xanthophyll), lutein (lutein) and any combination thereof, and more preferably β-carotene.

According to the present invention, based on the weight of the oxidizable polymer resin, the amount of the transition metal catalyst may be about 0.001 to about 5 wt%, preferably about 0.01 to about 4 wt%, and more preferably about 0.1 to about 2 wt%; And the amount of the sensitizer ranges from about 0.5 to about 5 wt%, preferably from about 0.75 to about 4 wt%, and more preferably from about 1 to about 3 wt%.

Although not required, additives can be used in oxygen scavenging formulations. Conventional additives include (but are not limited to) (i) fillers and reinforcing agents, such as calcium carbonate, silica, glass fibers, glass balls, talc, kaolin, mica, barium sulfate, metal oxides and hydroxides, carbon black , Graphite, wood flour, other natural product powders, synthetic fibers: stearates used as fillers (such as zinc stearate or calcium stearate); (ii) pigments, such as carbon black, in its rutile ( rutile) or anatase form of titanium dioxide and other colorants; (iii) light stabilizers and/or antioxidants; and (iv) processing additives, such as anti-skid/anti-caking additives, plasticizers, optical brighteners Agent, antistatic agent and foaming agent.

In the process of producing the oxygen-scavenging formulation of the present invention, the transition metal catalyst, photosensitizer, and optionally additives can be blended with the oxidizable polymer resin simultaneously or sequentially or also immediately before the actual processing step.

The oxygen-scavenging formulation of the present invention can be in the form of an oxygen-scavenging film, and can be sprayed or dust-removed by drying or wetting, or by rolling or coating with a Mayer bar or doctor blade, or by Printing means (for example, using gravure or elastic relief printing) or by using electrostatic transport to coat the oxygen scavenging film on the substrate.

The oxygen-scavenging formulation according to the present invention can be used to manufacture encapsulated products, such as single-layer or multilayer plastic films, sheets, laminates, bags, bottles, polystyrene foam cups (styrofoam cups), utensils, bubble packaging, boxes And packaging cladding. The packaged products can be manufactured by any process available to those skilled in the art, including (but not limited to) extrusion, extrusion blow molding, film casting, film blow molding, calendering, injection molding, blow molding, compression molding, and thermoforming , Textile, blow molding, extrusion and rotary casting.

The packaged product can be a multilayer food package including an outer layer, a food contact layer and an oxygen scavenging film. The outer layer uses polyolefin resin, preferably (i) EVA, (ii) EAO (such as VLDPE) and (iii) a blend of ethylene-hexene-1 copolymer with a melting point (mp) of 80 to 98°C . The food contact layer is an inner layer and can also act as a sealant layer. Suitable materials for the food contact layer should be thermally stable above 150°C and should comply with all FDA guidelines for contact with aqueous and fatty foods under all conditions experienced during packaging, storage, and cooking. Examples of food contact layers include polyester, acrylic polymer, and silicone. Preferably the food contact layer is a polypropylene (PP) layer.

The multilayer food packaging product may further include an intermediate layer disposed between the oxygen scavenging film and the outer layer and/or between the oxygen scavenging film and the food contact layer. A common suitable intermediate layer is an adhesive layer on either side of the oxygen scavenging film connected to the outer layer or the food contact layer. A preferred component of the adhesive layer is EMAC SP 1330 and polyurethane (PU).

In one embodiment of the present invention, a multilayer packaging film for food packaging can be produced by coating an oxygen scavenging formulation on a plastic substrate to produce an oxygen scavenging film. After drying, the oxygen scavenging film can be attached to the food contact layer containing the adhesive. The multilayer packaging film for food packaging can also be produced by coating the oxygen scavenging formulation on the food contact layer to produce an oxygen scavenging film. Subsequently, the oxygen scavenging film can be attached to the printed outer layer containing the adhesive. After that, the multi-layer packaging film for food packaging including the outer layer, food contact layer, oxygen scavenging film and optional adhesive layer as the intermediate layer should be rolled to prevent the oxygen scavenging film from contacting oxygen.

One of the advantages of the oxygen-scavenging formulation of the present invention is that the oxidation reaction does not need to be activated by water or triggered by high temperature or light. However, usually UV light or pulsed light triggers the process to promote the oxidation reaction of the oxygen scavenger. Therefore, the oxygen-scavenging formulation of the present invention is also applicable to any conventional light-triggered process or system.

In view of the above, the present invention also provides a method for reducing the oxygen atmosphere in an encapsulated product, which comprises providing an oxygen-scavenging formulation to the encapsulated product to allow the oxygen-scavenging formulation to contact oxygen, wherein the oxygen-scavenging formulation includes an oxidizable polymer Resin, transition metal catalyst and photosensitizer selected from one or more carotenoids.

The present invention also provides a method for reducing the oxygen atmosphere in an encapsulated product, which comprises a) exposing an oxygen scavenging formulation to UV radiation to trigger oxygen removal, wherein the oxygen scavenging formulation includes an oxidizable polymer resin and a transition metal catalyst; And b) providing the triggered oxygen scavenging formulation to the inside of the encapsulated product to allow the oxygen scavenging formulation to contact oxygen and reduce the oxygen atmosphere in the encapsulated product.

The present invention also provides a method for reducing the oxygen atmosphere in an encapsulated product, which comprises the following steps: a) exposing a multilayer encapsulation film containing an oxygen scavenging film to UV radiation to trigger oxygen removal; wherein the oxygen scavenging film is composed of an oxidizable polymer The composition is composed of a deoxygenation formulation of a resin, a transition metal catalyst, and a sensitizer selected from one or more carotenoids; and b) sealing the multilayer encapsulation film to form an encapsulation product to allow the deoxidation formulation to contact oxygen and reduce the encapsulation product In the oxygen atmosphere.

According to the present invention, the exposing step includes exposing the oxygen scavenging formulation to UV radiation, the UV radiation having about 250 mJ/cm ² to 600 mJ/cm ² , preferably about 350 mJ/cm ² to 600 mJ/cm ² , more The energy density of the ultraviolet C (UVC) band is preferably about 450 mJ/cm ² to 600 mJ/cm ^2.

In an embodiment of the present invention, the oxygen scavenging formulation is present on the inner layer of the encapsulated product.

The above implementations of the embodiments of the present invention are not intended to be exhaustive or to limit the present invention to the exact form disclosed above. Those familiar with the related art will recognize that although the specific embodiments and examples of the present invention described above are for illustrative purposes, various equivalent modifications can be made within the scope of the present invention. Example Example 1 : Preparation of multilayer structure containing oxygen scavenging film

To prepare a deoxygenation formulation containing β-carotene, 0.03 g β-carotene (1 wt%) was added to 9 g butyl acetate solvent, and the resulting solution was heated to dissolve β-carotene. Under continuous stirring and heating, 3 g of styrene-butadiene-styrene and 0.03 g of cobalt neodecanoate (1 wt%) were then added to the solution to obtain a deoxygenated formulation containing 1 wt% β-carotene Things. (The above weight percentages are based on the total weight of styrene-butadiene-styrene.) The formulation is coated on the terephthalate (PET) substrate by using a doctor blade. The coated PET substrate was dried at 80°C, so that the oxygen-scavenging formulation on the PET substrate became an oxygen-scavenging film with a thickness of 45 μm.

The comparative film was prepared according to the process described above, in which a blank film was obtained without the addition of β-carotene, and by using 0.03 g of benzophenone (based on the total of styrene-butadiene-styrene). 1 wt% by weight) replace β-carotene to obtain an oxygen scavenging film containing benzophenone. Example 2 : Exposure to UV light

The β-carotene-containing film, the blank film, and the benzophenone-containing film prepared in Example 1 were cut into pieces ^{with an area of 9 cm 2.} The surface of the formulation coated with each of the films was then exposed to a 400 W UV lamp with the intensity distribution profile listed in Table 1 at a distance of 7 cm for 10 seconds: Table 1

After exposure, the membranes were individually placed in 11 ml airtight bottles. The oxygen concentration of each of the bottles is measured at intervals by gas chromatography (Trace 1310). As shown in Figure 1, the oxygen scavenging effect of both the film containing 1 wt% β-carotene or 1 wt% benzophenone can be triggered by exposure to UV light for 30 seconds. In addition, within five hundred hours, the deoxygenation effect achieved by a deoxygenation membrane containing 1 wt% β-carotene is similar to that achieved by a deoxygenation membrane containing 1 wt% benzophenone (a conventional trigger) Deaeration effect. The above results prove that the commonly used triggers (such as benzophenone) can be replaced by natural and water-insoluble β-carotene. Example 3 : The influence of the energy density of ultraviolet C light

The oxygen scavenging film containing 1 wt% β-carotene prepared in Example 1 was individually exposed to a 400 W UV lamp with a UVC power density of ^{19 mV/cm 2 for 0, 15, 20, 25 or 30 seconds.} The energy density (mJ/cm ² ) of the UVC band can thus be calculated by multiplying the power density (19 mV/cm ² ) by the exposure time (0, 15, 20, 25 or 30 sec). Similarly, the exposed films were individually placed in 11 ml airtight bottles. The oxygen concentration of each of the bottles is measured at intervals by gas chromatography (Trace 1310). As shown in Figure 2(a) and Figure 2(b), when the oxygen scavenging film containing 1 wt% β-carotene is exposed to UVC light with an energy density of ^{285 mJ/cm 2 or higher, it can} Trigger the oxygen removal effect of the oxygen removal membrane containing 1 wt% β-carotene within 25 hours. Example 4 : Effect of the amount of β -carotene

0.015 g, 0.03 g, and 0.09 g β-carotene (0.5 wt%, 1 wt%, or 3 wt%) were added to 9 g butyl acetate solvent, respectively, and the resulting solution was heated to dissolve β-carotene. Under continuous stirring and heating, 3 g of styrene-butadiene-styrene and 0.03 g of cobalt neodecanoate (1 wt%) were then added to each of the solutions to obtain 0.5 wt%, 1 wt% Three deoxygenation formulations of wt% and 3 wt% β-carotene. (The above weight% is calculated based on the total weight of styrene-butadiene-styrene.) The formulation is coated on a terephthalate (PET) substrate by using a doctor blade. The coated PET substrate was dried at 80°C, so that the oxygen-scavenging formulation on the PET substrate became an oxygen-scavenging film with a thickness of 45 μm.

Cut the oxygen scavenging film containing 0.5 wt%, 1 wt% and 3 wt% β-carotene into ^{pieces with an area of 9 cm 2} and expose the surface coated with the scavenging formulation to a distance of 7 cm A 400 W UV lamp with a power density of 19 mW/cm ^{2 in} the UVC band for 30 seconds (equivalent to an energy density of ^{570 mJ/cm 2).} After exposure, the membrane was individually placed in an 11 ml airtight bottle. The oxygen concentration of each of the bottles is measured at intervals by gas chromatography (Trace 1310).

As shown in Figure 3(a) and Figure 3(b), after being ^{triggered by UVC light with an energy density of 570 mJ/cm 2} , a film containing 1 wt% or more than 1 wt% β-carotene can be Deoxygenation effect can be displayed within ten hours. Example 5 : Preparation of deoxidizing package

Add 0.009 g, 0.03 g, and 0.09 g β-carotene (0.3 wt%, 1 wt%, or 3 wt%) to 9 g butyl acetate solvent, respectively, and heat the resulting three solutions to dissolve β-carotene . Under continuous stirring and heating, 3 g of styrene-butadiene-styrene and 0.03 g of cobalt neodecanoate (1 wt%) were then added to the solution to obtain a β-carotene-containing deoxygenation formulation. (The above-mentioned weight percentages are based on the total weight of styrene-butadiene-styrene.) Then, the formulations were respectively coated on the polypropylene (PP) substrate by using a doctor blade. The coated PP substrate was dried at 80°C, so that the oxygen-scavenging formulation on the PP substrate became an oxygen-scavenging film with a thickness of 25 μm. #6 coating rod is used to coat polyurethane (PU) adhesive on polyethylene terephthalate (PET) substrate. After the coated PET substrate is dried, the PU adhesive side of the PET substrate is attached to the oxygen scavenging film of each of the PP substrates to form a thin layer. Place the formed thin layer separately in an aluminum foil bag.

The resulting thin layer is cut into pieces with a ^{size of 3×3 cm 2.} PP substrates from two thin-layer pieces of the same thin layer are configured to face each other, and the two thin-layer pieces are sealed to form a package. Then 11 ml of air was injected into each of the packages. The oxygen concentration in the package was measured at intervals by gas chromatography (trace 1310). The results are shown in Table 2: Table 2

The above results show that when the amount of β-carotene is 3 wt% or more than 3 wt% based on the weight of styrene-butadiene-styrene, the oxygen scavenging formulation can significantly reduce the oxygen concentration in the package. No need to use triggers or heat or light. Example 6 : Other carotenoids

Films each containing 1 wt% β-carotene, lycopene, retinol or astaxanthin were prepared according to the process described in Example 1 and then exposed to the 400 described in Example 2 at a distance of 7 cm W UV lamp for 30 seconds. As shown in Figure 4, the deoxygenation effect can be triggered by all membranes each containing 1 wt% of different carotenoids.

Figure 1-(a) and (b) respectively illustrate the reduced oxygen concentration and oxygen content in an 11 ml gas-sealed bottle with respect to the blank film and the oxygen scavenger film containing 1 wt% benzophenone or 1 wt% β-carotene The change in clearing time. Figure 2-(a) and (b) respectively illustrate the reduced oxygen concentration and oxygen content in an 11 ml gas-sealed bottle with respect to the oxygen scavenger containing 1 wt% β-carotene when exposed to UVC light with different energy densities Changes in the removal time of the membrane. Figure 3-(a) and (b) respectively illustrate the changes of the reduced oxygen concentration and oxygen content in the 11 ml gas sealed bottle with respect to the scavenging time of the oxygen scavenger film containing different amounts of β-carotene. Figure 4 illustrates the change of oxygen concentration in an 11 ml gas-sealed bottle with respect to the clearance time of a membrane containing 1 wt% β-carotene, lycopene, retinol or astaxanthin.

Claims (16)

An oxygen-scavenging formulation comprising an oxidizable polymer resin, a transition metal catalyst, and a sensitizer selected from one or more carotenoids, wherein the amount of the sensitizer ranges from the weight of the oxidizable polymer resin About 0.5 to about 5wt%. Such as the deoxygenation formulation of claim 1, wherein the carotenoid is lycopene, zeaxanthine, retinol, cantaxanthine, α-carotene, β-carotene , Γ-carotene and δ-carotene, astaxin, astaxanthin, chrysanthemaxanthin, torularhodin, violaxanthin, capsanthin , Capsorubin (capsorubin), riboflavin (riboflavin), lutein (xanthophyll), or lutein (lutein). The oxygen-scavenging formulation of claim 1 or 2, wherein the oxygen-scavenging formulation is in the form of an oxygen-scavenging film coated on a substrate. Such as the oxygen-scavenging formulation of claim 3, wherein the substrate is an outer layer and/or an inner layer of an encapsulated product. The oxygen-scavenging formulation of claim 4, wherein the encapsulated product further includes an intermediate layer and/or an adhesive layer. A method for reducing the oxygen atmosphere in an encapsulated product, which comprises providing an oxygen-scavenging formulation to the encapsulated product to allow the oxygen-scavenging formulation to contact oxygen and reduce the oxygen atmosphere in the encapsulated product, wherein the oxygen-scavenging formulation The substance includes an oxidizable polymer resin, a transition metal catalyst, and a sensitizer selected from one or more carotenoids, wherein the amount of the sensitizer ranges from about 0.5 to about 5 wt% based on the weight of the oxidizable polymer resin . The method of claim 6, wherein the carotenoid is lycopene, zeaxanthin, retinol, cantharidin, α-carotene, β-carotene, γ-carotene and δ-carotene, shrimp Rubin, astaxanthin, chrysanthemum, red yeast red, purple red, pepperin, capsanthin, riboflavin, lutein, or lutein. A method for reducing the oxygen atmosphere in an encapsulated product, comprising: a) exposing an oxygen scavenging formulation to UV radiation to trigger oxygen removal, wherein the oxygen scavenging formulation includes an oxidizable polymer resin, a transition metal catalyst, and a catalyst selected from the group consisting of One or more carotenoid photosensitizers, wherein the amount of the photosensitizer ranges from about 0.5 to about 5 wt% based on the weight of the oxidizable polymer resin; and b) providing the triggered deoxygenation formulation to The inner side of the packaged product allows the oxygen scavenging formulation to contact oxygen and reduces the oxygen atmosphere in the packaged product. The method of claim 8, wherein the exposing step comprises exposing the oxygen scavenging formulation to the UV radiation having an energy density in the ultraviolet C (UVC) band of ^{about 250 mJ/cm 2} to 600 mJ/cm ^2. Such as the method of claim 8 or 9, wherein the carotenoid is lycopene, zeaxanthin, Retinol, cantharidin, α-carotene, β-carotene, γ-carotene and δ-carotene, astaxanthin, astaxanthin, chrysanthemum, red yeast red, violaxanthin, pepper Flower element, capsaicin, riboflavin, lutein, or lutein. The method of claim 8 or 9, wherein the oxygen-scavenging formulation is in the form of an oxygen-scavenging film coated on a substrate. A method for reducing the oxygen atmosphere in an encapsulated product, which comprises: a) exposing a multilayer encapsulation film containing an oxygen scavenging film to UV radiation to trigger oxygen removal, wherein the oxygen scavenging film is composed of an oxygen scavenging formulation containing the following: An oxidizable polymer resin, a transition metal catalyst, and a photosensitizer selected from one or more carotenoids, wherein the amount of the photosensitizer ranges from about 0.5 to about 5 wt% based on the weight of the oxidizable polymer resin; and b) sealing the multilayer packaging film to form the packaging product to allow the oxygen scavenging formulation to contact oxygen and reduce the oxygen atmosphere in the packaging product. The method of claim 12, wherein the exposing step includes exposing the oxygen scavenging film to the UV radiation having an energy density of ^{about 250 mJ/cm 2} to 600 mJ/cm ^{2 in an ultraviolet C (UVC) band.} The method of claim 12 or 13, wherein the carotenoid is lycopene, zeaxanthin, retinol, cantharidin, α-carotene, β-carotene, γ-carotene, and δ-carotene , Astaxanthin, astaxanthin, chrysanthemum, red yeast red, violaxanthin, peppolin, capsanthin, riboflavin, lutein, or lutein. Such as the method of claim 12 or 13, wherein the multilayer packaging film further includes an outer layer, an inner layer, and an adhesive layer as appropriate. The method of claim 15, wherein the oxygen scavenging film is coated on the outer layer or the inner layer.

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