MXPA97009989A - Cover lid for oxygen absorbing container - Google Patents

Abstract

The present invention relates to a container lid, characterized in that it comprises: a base portion having a perimeter, a substantially cylindrical portion extending perpendicularly from said perimeter of said base portion and defining an internal surface of said lid. container, and a fully discovered resin liner disposed in direct contact with said inner surface of said container lid, and which is attached to said internal surface with sufficient contact force to avoid additional mechanisms of mechanical sealing, said liner having an oxygen absorber dispersed therein, whereby said container lid is adapted to seal an opening in a container and to absorb the oxygen contained therein.

Description

PFlRfl TflPfl LINK OXYGEN ABSORBING CONTAINER FIELD OF THE INVENTION This invention relates generally to oxygen absorbers. It relates in particular to an oxygen absorber dispersed in a liner of a container lid.

BACKGROUND OF THE INVENTION Many products are susceptible to putrefaction, denaturation, mold growth, alteration, rancidity, oxidation, or other deterioration when brought into contact with oxygen. Examples of such products include beer, wine, juice, vinegar, sauces, seasonings, processed foods, bread, agricultural foods, meat and pharmaceutical and chemical products, among a variety of other things. The conservation of these products is distributed when mold, bacteria and other organisms that thrive in the presence of oxygen are present. These organisms cause putrefaction and change the flavor or quality of the product. In addition, some of the same products are likely to be affected by oxidation that changes the taste or quality of the product. In order to avoid such oxidation and growth of organisms and therefore to increase the storage stability of these products, the oxygen must be removed from the container in which the products are stored. One technique to avoid or reduce the presence of oxygen is packing under vacuum. This involves evacuating a container before loading it with the product. Another technique is the displacement of gas. Here an inert gas such as nitrogen is used to displace air and therefore oxygen in a container. The displacement can be done before or after the product is loaded into the container. Another technique is a spurning method. Particularly applicable to products such as beers, a jet skimmer can be used to inject a small amount of water under pressure to froth the beer before loading it into the container. The foam acts as a mechanical deoxygenizer, forcing oxygen out of the container. The common disadvantages associated with all the above techniques are the requirement of large-scale apparatus and operation and the difficulty of removing dissolved oxygen in the product achieved also, in general, that techniques leave between 0.2% and 5.0% oxygen in the container. This amount of oxygen in the container is enough to adversely affect most products. A simpler, more efficient technique for removing oxygen involves placing an oxygen absorber in the container with the product. For this purpose, it is known to fix an oxygen absorber on the underside of the lid of the container. For example, in the patent of E.U.fl. Do not.

No. 4,287,995, issued a rioriya, an oxygen absorber is placed on the underside of the lid. The oxygen absorber is held in place by a gas-permeable film cover layer which prevents contact between the absorber and the contents of the container. The Patent of E.U.P. No. 5,143,763, issued to Ya ada et al., Discloses a multi-layer composition adapted to be fixed to a liner on the underside of the lid of the container. The layers of the composition include (1) an adhesive layer that fixes the multi-layered structure to the liner of the lid, (2) an oxygen absorbing layer consisting of an oxygen absorber dispersed in a resin, and (3) a oxygen permeable film layer covering the absorber layer. The oxygen permeable film layer prevents the oxygen absorber from leaving the resin to the contents of the container. The adhesive layer is disposed between the liner of the lid and the oxygen absorbing layer, completely separating the liner from the lid of the oxygen absorbing layer. The Patent of E.U.fi. No. 5,274,024, issued to Koyama et al., Also discloses a multi-layer composition adapted to be affixed to the underside of a container lid. The Patent describes an adhesive layer, used to fix an oxygen absorbing layer to the lid, and an outer layer on the oxygen absorbing layer. The outer layer prevents direct contact between the contents of the container and the oxygen absorber. Again, the adhesive layer is arranged between the cap and the oxygen absorbing layer, completely separating the cap from the oxygen absorbing layer. However, in all known devices, the separated layers are used to achieve the functions of coating the lid in the container, adhering the oxygen absorber to the lid, absorbing the oxygen and covering the oxygen absorber to prevent contact with the content inside the container.

BRIEF DESCRIPTION OF THE INVENTION The present invention provides a container lid having a base portion, a substantially cylindrical portion extending perpendicularly from a perimeter of the portion of the base to define an internal surface of the container lid, and an uncovered liner disposed directly on the inner surface of the lid of the container, the liner having an oxygen absorber disposed therein. The lid of the container is adapted to seal an opening in a container and to absorb oxygen within the container. The present invention also provides a method for removing oxygen from a container by dispersing an oxygen absorber in a liner, fixing the liner directly to an inner surface of a container lid and placing the lid over an opening in the container such that the Liner on the lid of the container seals the opening and absorbs oxygen inside the container.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a cross-sectional side view of an oxygen absorbing container lid in accordance with an illustrative embodiment of the present invention; Figure 2 is a partially cross-sectional perspective view of an oxygen absorbing container lid in accordance with an illustrative embodiment of the present invention; Figure 3 is a partially cross-sectional side view of an oxygen absorbing container lid attached to the container in accordance with an illustrative embodiment of the present invention; Figure 4 is a cross-sectional side view of an oxygen absorbing cap in accordance with another illustrative embodiment of the present invention; Figure 5 is a top view of the embodiment shown in Figure 4.

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an oxygen absorbing cap with an oxygen absorber dispersed in the liner of the lid, the liner being directly attached to the inner surface of the lid. No cover layer is used on the lining. When said lid is secured to the container, the oxygen absorbing liner in the lid acts as a sealant, providing a seal between the lid and the container, and as an oxygen absorber, removing oxygen from the interior of the container. Figure 1 shows a side view of an illustrative embodiment of the present invention. The lid 11 includes a base portion 20 and a cylindrical portion 21 that is typically formed integrally with the base portion 20. The lid 11 may be a plastic material, such as polyvinyl chloride, polystyrene or polycarbonate. Chapter 11 can also be a metallic material, such as aluminum or iron. Slots 13 are formed on the inner surface of the lid 11 to coincide with the threads on the container opening (not shown). The liner 12 is disposed on the inner surface of the lid 11. The liner 12 in the illustrated embodiment includes a carrier resin with an oxygen absorbing material dispersed therein. Oxygen-absorbing materials useful in the present invention include iron, solid electrolyte salts, and glucose oxidase. The iron can be reduced iron with hydrogen, electrolytically reduced iron or chemically reduced iron. Although iron is preferred as the metal oxygen absorbing agent, it will be appreciated that other metals can be used. These are by way of example and not limitation, aluminum, copper, zinc, titanium, magnesium and tin. However, these other materials do not absorb oxygen as quickly as iron or have their oxygen absorbing capacity. Also, other elements that can be used in elemental or partially oxidized form are sodium, manganese, iodine, sulfur and phosphorus. These elements are not as effective as the iron because they do not have the oxygen absorbing capacity of the iron, the oxygen absorption rate of the iron or both. The oxygen absorbing salt may be sodium chloride or any other suitable compatible food salt including, but not limited to, sodium sulfate, sodium chloride, ammonium chloride, calcium phosphate and magnesium chloride. For products that are not food, other compatible salts that are not food can be used. A carrier resin for the oxygen absorbing material is preferably polyvinyl chloride plastisol. Plastisol of polyvinyl chloride is a known resin for coating the inner surface of container covers. Other resins that may be used as the carrier resin for the oxygen absorbing material and which also serve as suitable sealants include, but are not limited to, high density polypropylene, high density polyethylene, acrylic, ethylene vinyl acetate copolymer, ethylene vinyl acetate, polyvinyl acetate copolymer ethylene acetate copolymer, plasticized vinyl chloride, oxidized polyethylene homopolymer, and polyurethane. When plastisol of polyvinyl chloride is used as the carrier resin up to 75% by weight of the liner 12 it can be maya steel 200, a preferred oxygen absorber. The liner 12 is prepared by dispersing the oxygen absorbers within the vehicle resin (in a viscous liquid state) by mixing in a high speed electric mixer. The liner 12 is then sprayed onto the inner surface of the lid 11 in liquid form in accordance with methods known in the art. The liner 12 adheres to the lid 11, the lid 11 and the liner 12 are then heated (approximately 204.4 ° C for 2 1/2 minutes) to solidify the liner 12. Figure 2 is a perspective view showing the lining 12 coated on the inner surface of the lid 11. The lid 11 is fixed to a container by first heating the lid 11 until the liner 12 is softened. The lid 11 is then treated on the container, forming a thread in the liner 12 corresponding to the slots 13 in the cylindrical position 21 of the lid 11. As shown in Figure 3, the lid 11 fits securely over the opening of the container 15. The liner 12 seals the lid 11 to the container 15. In this way, the liner 12 ensures a proper fitting between the lid .1.1 and the container 15 and will facilitate the sealing function. In addition, the liner 12 absorbs oxygen within the container 15 without the need for additional layers, such as cover layers or adhesive layers. The invention provides an economical and practical method for absorbing oxygen within a container by combining the adhesive function (fixing the liner 12 to the lid 11), the oxygen absorbing function, and the sealing function of the container in a single element: the lining 12. Figure 4 is a side view of an alternative embodiment of the present invention. In the illustrative embodiment, the lid 11 has a peripheral liner 30 disposed about the intersection of the base portion 20 and cylindrical portion 21. The peripheral liner 30 extends over the slots 13 such that the slots will be formed in the lining peripheral 30 as the lid 11 is fixed to a container. This ensures sealing of the lid 11 to the container. The peripheral liner 30 does not include an oxygen absorber. The embodiment illustrated in Figure 4 also includes a central liner 31. The central liner 31 is disposed on the inner surface of the base portion 20. The central liner 31 is centrally arranged and circular in the illustrated embodiment, but any shape or thickness. The central liner 31 contains an oxygen absorber that absorbs oxygen within the container to which the lid 11 is attached. The oxygen absorber is dispersed in the central liner 31 as described above. The peripheral liner 30 and the central liner 31 are both sprayed on the lid 11 according to methods known in the art., and then heated to solidification. Figure 5 is a top view of the embodiment illustrated in Figure 4. This embodiment preserves the vehicle resin material used for the liners and oxygen absorbers. The following examples are presented to illustrate the present invention; They do not intend to limit it.

EXAMPLE 1 Plastisol of polyvinyl chloride in an amount of 10.35 grams was mixed with 12.51 grams of 200 mesh iron containing 2% sodium chloride. The mixture was made in a high speed electric mixer. A sample of the resulting lining material was coated on the inner surface of a container lid. The lid of the container was placed in a 500 cm3 clay flask containing 100 crn * of oxygen. A hole of 0.317 cm was made in the lid of the clay flask with a division placed over the hole to prevent oxygen escaping from the container. The container was left at room temperature at 100% relative humidity inside the bottle, and the amount of oxygen reabsorbed by the liner of the lid was measured. This procedure was repeated twice using different weights of lining material inside the lid. The results are tabulated below.

Oxygen absorbed over time (aiP) Sample Sample Sample Average # 1 # 2 # 3 Time (1 .47 gms *) (1 .71 gms *) (1 .51 gms *) (1. .56 gms *) 22 hrs 10 10 10 10 46 hrs 15 14 15 15 96 hrs 24 22 24 23 184 hrs 37 32 34 34 234 hrs 37 32 37 35 330 hrs 51 41 48 47 * Weight of the coated lining on the inner surface of the lid. EXAMPLE 2 Plastisol of polyvinyl chloride in an amount of 8.40 grams was mixed with 5.17 grams of 200 mesh iron containing 2% sodium chloride in a high speed electric mixer. A sample of the resulting liner composition was coated on the inner surface of a container lid, which was placed in a 500-cc jar containing 100 cm3 of oxygen. A .317 cm hole was made in the mud flap lid with a split placed over the hole to prevent oxygen escaping from the container.

The container was left at room temperature at 100% relative humidity inside the bottle and the amount of oxygen absorbed by the liner with time was measured. The procedure was repeated twice using different weight samples of liner inside the lid. The results are tabulated below.

Oxygen absorbed over time (cm3) Sample Sample Sample Average # 1 # 2 # 3 Time (1 .47 gms *) (1 .71 gms *) (1 .51 gms *) (1. .56 gms *) 22 hrs 8 8 8 8 46 hrs 12 12 12 12 96 hrs 26 19 21 22 184 hrs 46 30 30 35 234 hrs 52 33 30 38 330 hrs 61 43 41 48 * Weight of the coated lining on the inner surface of the lid.

The results of Examples 1 and 2 show good oxygen uptake using the present invention. Using the invention, the results are achieved with reduced material and reduced manufacturing time. Although illustrated and described herein with reference to certain specific embodiments, the present invention is not intended to be limited to the details shown. Rather, various modifications can be made to the details within the scope and scale of equivalents of the claims and without departing from the spirit of the invention.

Claims (7)

NOVELTY OF THE INVENTION CLAIMS

1. - A container lid comprising: a base portion having a perimeter; a substantially cylindrical portion extending perpendicularly from said perimeter of the base portion and defining an internal surface of said container lid; and a completely uncoated resin layer disposed in direct contact with the inner surface of the container lid, said layer having an oxygen absorber dispersed therein, whereby said container lid is adapted to seal an opening in a container and to absorb oxygen inside said container.

2. A container lid according to claim 1, further characterized in that said liner is plastisol of polyvinyl chloride.

3. A container lid according to claim 1, further characterized in that said oxygen absorber is selected from the group consisting of iron, aluminum, copper, zinc, titanium, magnesium, tin, sodium, manganese, iodine, sulfur, phosphorus, sodium chloride, sodium sulfate, potassium chloride, ammonium chloride, ammonium sulfate, calcium chloride, sodium phosphate, calcium phosphate, glucose oxidase and magnesium chloride.

4. - A method for removing oxygen from a container comprising: dispersing an oxygen absorber in a resin liner; fixing the completely uncovered liner, immediately on an interior surface of a container lid without a separate adhesive; and placing the lid over an opening in the container such that the liner in the lid of the container seals the opening and absorbs oxygen within the container.

5. A method according to claim 4, further characterized in that the liner is plastisol of polyvinyl chloride.

6. A method according to claim 4, further characterized in that the liner is fixed to the inner surface of the lid of the container by spraying the liner in liquid form on the inner surface.

7. A method according to claim 4, further characterized in that the oxygen absorber is selected from the group consisting of iron, aluminum, copper, zinc, titanium, magnesium, tin, sodium, manganese, iodine, sulfur, phosphorus, sodium chloride, sodium sulfate, potassium chloride, ammonium chloride, ammonium sulfate, calcium chloride, sodium phosphate, calcium phosphate, glucose oxidase and magnesium chloride.