FIELD OF THE INVENTION : The present invention generally relates to an induction seal for maintaining the integrity of a container for a beverage or drink (e. g food product) or other environmentally sensitive products (e. g. pharmaceutical products). The induction seal also acts as an active component (e. g. controlling the release of a aroma and/or absorbing oxygen). In one embodiment, the induction seal is composed of a composition having co-continuous interconnecting channel morphology comprising three components--two polymers (i. e. components A and B) and a particle (i. e. component C) wherein the channels consist mainly of component B and the majority of component C resides in the channels. Components A and B are generally immiscible within each other. In addition, one criteria for selecting component C and components A and B may be based on component C preferential affinity for component B over component A. Another criteria for selecting component C may be based on the capacity of component C to absorb and/or release a desired substance. For example, component C may be an inclusion compound such as a cyclodextrin.

BACKGROUND OF THE INVENTION: Plastic materials offer the packaging industry many benefits including a degree of design flexibility. Specifically, polyethylene terephthalate (PET) has made significant inroads into bottling and packaging applications at the expense of the use of glass containers but primarily in applications where the needs for barrier properties are modest. An increased wall thickness is needed to improve the barrier properties of the container but has a negative impact on the economics of the container. The ratio of packaging material to package volume has typically limited PET bottles to multi-serve container uses for packaging of oxygen sensitive foods and beverages such as fruit juices and drinks. As the oxygen sensitivity of the packaged product increases or as the size of the package decreases, at some point the ratio of packaging material versus package volume becomes prohibitive. When that occurs, the production and use of thick walled conventional PET bottles may no longer be economically viable as the cost of the packaging is disproportionate to the value of the packaged product.

Moreover, when compared to traditional packaging materials such as glass and steel, plastics such as PET offer inferior barrier properties which limits their acceptability for use in packaging items that are sensitive to atmospheric gases, particularly when the exposure to the atmospheric gases will entail extended time periods. In response to this inferior barrier properties, the packaging industry has attempted to develop technology to improve the barrier properties of plastic containers by developing multi-layer containers that offer mixed polymer layers. These laminated packaging containers offer improved barrier properties but sacrifice many of the recycling benefits associated with single layer containers such as PET and polyethylene naphthalate (PEN) bottles. Furthermore, depending on the mixtures of polymers, copolymers, blends, etc., used in the layers, clarity of the layered container is often substantially diminished.

In addition to barrier properties, in the case of"oxygen sensitive"materials, including foods, beverages, and pharmaceutical products, special packaging requirements must be employed to prevent the ingress of exterior oxygen into the package and/or to scavenge oxygen which is present inside the package. In some cases, particularly in the orange juice industries, oxygen is conventionally removed from the product by vacuum or by inert gas sparging, or both. This technology, while somewhat equipment intensive, can remove up to about 95% of the oxygen present in air from the product or its container prior to or during packaging. However, removal of the remaining oxygen using this approach requires longer times for vacuum treatment and/or sparging and increasingly larger volumes of higher and higher purity inert gas that must not itself be contaminated with trace levels of oxygen. This makes the removal of the last traces of oxygen very expensive. A further disadvantage of these methods is a tendency to remove volatile product components--the same volatile components that are mainly responsible for the juices flavor and/or aroma.

Specifically, molecular oxygen can be reduced to a variety of highly reactive intermediate species by the addition of one to four electrons. The carbon-carbon double bonds found in virtually all foods and beverages are particularly susceptible to reaction with these intermediate species. The resulting oxidation products adversely affect the performance, odor or flavor of the product. As a result, the industry have developed"oxygen scavengers."An "oxygen scavenger"is any material or compound which can remove oxygen from the interior of a closed package either be reacting or combining with the entrapped oxygen, or by promoting an oxidation reaction which yields innocuous products.

In addition, many containers are typically sealed with"induction seals"as an additional method of preventing oxygen ingress into the container. In one example, induction seals are generally composed of aluminum foil with a plastic sealant layer with adhesive.

Ribbons of this foil/plastic lamination are used by the cap/lid makers to die-cut seals and friction fit them into the caps/lids. In high speed filling lines, once the containers are filled and the caps fitted with induction seals mounted on the containers... bottles, jars, cartons, etc..., the containers pass through a radio-frequency tunnel. The radio frequency activates the adhesive on the induction seal liner and it adheres to the container's access rim. In the case of bottles or cartons, the caps/lids are then tightened. In another example, the induction seal may be composed completely of a plastic material that is sealed by a conventional induction heating process.

DETAILED DESCRIPTION OF THE INVENTION : As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention.

The present invention relates to an induction seal composed of the interconnecting channel morphology of the present invention. In one embodiment, the induction seal is essentially an"active"layer. This is accomplished by having components B and/or C selected so that it has the desired capacity to absorb and/or release a desired substance. For example, component C may be an inclusion compound such as a cyclodextrin. This"active" layer may either be between the aluminum foil and the plastic sealant layer with adhesive or composed of the plastic sealant layer. This enables the induction seal to act as active "managers"of what is inside the container/package.

In another embodiment of the present invention relating to induction seals, a closure for a container (e. g. bottle, carton) includes an inner seal, which is sealed to an outlet opening of the container by a conventional induction heating process or the like to form an"induction" seal. With an induction seal, a hermetic, vacuum retaining seal can be provided for maintaining the integrity of the beverage. This inner seal may also eliminate the possibility of leakage during distribution and storage of the container but is also designed to be removable when the consumer intentionally applies sufficient force so as to access the contents of the container. Further, the induction seal may also prevent the liquid (e. g. beverage) in the container from coming into contact with the closure or cap of the container. In another embodiment, to facilitate removal of the induction the seal, the induction seal may include suitable pull tabs, as is conventional. In another embodiment, the closure or cap further includes a closure base having an internally threaded sleeve which is threadedly joined to the outlet opening of the container. The closure base also includes a tubular spout which communicates with the outlet opening of the bottle and through which the beverage contained in the bottle is adapted to be dispensed.

In yet another embodiment, the interconnecting channel morphology of the present invention may be used as liners or gaskets in crowns or closures for capping beverage containers. Entire closures may also be made of plastics containing compositions of the invention, for instance all plastic screw-on threaded caps for soft drink bottles, and the like.

Another preferred use of the composition of the invention is as a gasket or liner applied to an aluminum or plastic closure or metal crown for plastic or glass bottles.

In one embodiment, the interconnecting channel morphology composition of the present invention may be formed comprising at least three components, wherein: (a) component A is selected from the group of polymers that are semicrystalline polymers and amorphous polymers, wherein the amorphous polymers have a shear modulus greater than about 8 MPa; (b) component B is a polymer; (c) components A and B are immiscible within each other, and if components A and B react after mixing, components A and B are immiscible prior to reacting; (d) component C is a particle; (e) the volume fraction of component A represents at least about 50% by volume of the total volume of components A, B and C; (f) the preferential affinity between component B and component C is greater than between component A and component C; (g) at least two phases are formed, one phase is composed of a majority of component A, and the second phase is composed of a majority of components B and a majority of component C; and (h) two phases form the co-continuous interconnecting channel morphology.

Components A, B and C may be selected based on the desired end-use result--e. g. the desired degree of oxygen absorption or aroma release. For example, component A may typically be selected based on its permeability properties (e. g. barrier properties), its chemical and/or temperature resistance properties, its molding properties, and/or its price (e. g. since it is the component having the largest volume fraction of the composition).

In one embodiment, component A may be composed of conventional bottle closure linings such as thermoplastic materials--PVC or EVA, polyethylene terephthalate ("PET"), polyolefins such as PE or PP, or blends thereof. In order to attain the optimum combination of moldability, resilience, sealability, etc., these materials may be formulated to include plasticizers, heat stabilizers, lubricants, blowing agents, antioxidants, pigments, and other additives. These additive components are well known to one skilled in the art.

Similarly, for example, component B may typically be selected based on its transport properties (e. g. transfer of the desired aroma or oxygen) and/or its preferential affinity with component C. Also, for example, component C may typically be selected based on its ability to retain the aroma component and control release the aroma. Consequently, a specific composition may be uniquely tailored and thus, uniquely optimized for a desired aroma release and/or oxygen absorption.

For example for aroma release and/or oxygen absorption (e. g. scavenging), component C may be an"inclusion"compound. For purposes of the present invention,"inclusion" compounds are materials that have cavities and act as hosts for other materials or ingredients which can be contained within them. Suitable inclusion compounds include cyclodextrins ("CD")--ring sequences of glycosidic units usually with 6,7, or 8 such units. Several derivatives are now available, for examples, through Wacker Biochem. Cyclodextrins may be used to host aroma-causing materials (e. g., natural esters) on the one hand and/or oxygen scavenging materials (e. g., a Vitamin A component such as alpha-tocopherol) on the other.

These cavities make the cyclodextrins capable of forming inclusion compounds with hydrophobic guest or host molecules of suitable diameters.

A cyclodextrin is an oligosaccharide composed of glucose monomers coupled together to form a conical, hollow molecule with a hydrophobic interior or cavity. The cyclodextrins of the instant invention can be any suitable cyclodextrin, including alpha-, beta-, and gamma- cyclodextrins, and their combinations, analogs, isomers, and derivatives. In one embodiment of the present invention, the cyclodextrins of the present invention may form an inclusion complex--a cyclodextrin functioning as a"host"molecule, combined with one or more "guest"molecules (e. g aroma compound or oxygen scavenger) that are contained or bound, wholly or partially, within the hydrophobic cavity of the cyclodextrin or its derivative.

Suitable cyclodextrins for the present invention include derivatives such as carboxymethyl CD, glucosyl CD, maltosyl CD, hydroxypropyl cyclodextrins (HPCD), 2- hydroxypropyl cyclodextrins, 2,3-dihydroxypropyl cyclodextrins (DHPCD), sulfobutylether CD, ethylated and methylated cyclodextrins, and oxidized cyclodextrins that provide aldehydes and any oxidized forms of any derivatives that provide aldehydes. Also included are altered forms, such as crown ether-like compounds prepared by Kandra, L., et al, J. Inclus.

Phenom. 2,869-875 (1984), and higher homologues of cyclodextrins, such as those prepared by Pulley, et al, Biochem. Biophys. Res. Comm. 5,11 (1961). These references, including references contained therein, are applicable to the synthesis of the preparations and components of the instant invention and are hereby incorporated herein by reference. The alpha-cyclodextrin consists of 6, the beta-cyclodextrin 7, and the gamma-cyclodextf°ifa 8 glucose units arranged in a donut-shaped ring. The specific coupling and conformation of the glucose units give the cyclodextrins a rigid, conical molecular structure with a hollow interior of a specific volume. The"lining"of the internal cavity is formed by hydrogen atoms and glycosidic bridging oxygen atoms, therefore this surface is fairly hydrophobic. These cavities can be filled with all or a portion of an molecule (e. g. a host molecule such as an aroma compound or an oxygen scavenger) with suitable size to form an"inclusion complex."Alpha-, beta-, and gamma-cyclodextrins can be obtained from, among others, American Maize- Products Company (Amaizo), Hammond, Ind.

More specifically, a cyclodextrin is a cyclic oligosaccharide consisting of at least six glucopyranose units joined by alpha. (l"4) linkages. Cyclodextrin is typically produced by a highly selective enzymatic synthesis. Cyclodextrin molecules typically have available for reaction with a chemical reagent the primary hydroxyl at the six position, of the glucose moiety, and at the secondary hydroxyl in the two and three position. Because of the geometry of the cyclodextrin molecule, and the chemistry of the ring substituents, all hydroxyl groups are not equal in reactivity. However, with care and effective reaction conditions, the cyclodextrin molecule can be reacted to obtain a derivatized molecule having all hydroxyl groups derivatized with a single substituent type. Such a derivative is a persubstituted cyclodextrin. Cyclodextrin with selected substituents (i. e.) substituted only on the primary hydroxyl or selectively substituted only at one or both the secondary hydroxyl groups can also be synthesized if desired. Further directed synthesis of a derivatized molecule with two different substituents or three different substituents is also possible. These substituents can be placed at random or directed to a specific hydroxyl.

In one embodiment, individual cyclodextrin derivatives as well as dimers, trimers and polymers function as the primary structures, or components, or units (i. e. monomer) used to synthesize the water soluble (or colloidal) cyclodextrin polymer carriers. A cyclodextrin dimer is defined as a unit of two cyclodextrin molecules covalently coupled or cross-linked together to enable cooperative complexing with a guest molecule. A cyclodextrin trimer is defined as a unit of three cyclodextrin molecules covalently coupled or cross-linked together to enable cooperative complexing with a guest molecule. A cyclodextrin polymer is defined as a unit of more than three cyclodextrin molecules covalently coupled or cross-linked together to enable cooperative complexing with several guest molecules. The cyclodextrin dimer, trimer and polymer units may be synthesized by covalently coupling through chemical groups such as coupling agents. Cooperative complexing means that in situations where the guest molecule is large enough, the member cyclodextrins of the CD dimer, trimer or polymer can each noncovalently complex with different parts of the same guest molecule, or with smaller guests, alternately complex with the same guest. In another embodiment, the captured guest molecule is covalently tethered through a spacer to the water soluble (or colloidal) CD polymer to allow formation of a noncovalent complex between the guest and the host CD within the polymer.

Cyclodextrin molecules have their functional groups only on the periphery so that the interior is nonreactive. Therefore, in this embodiment, the guest molecule can form a noncovalent inclusion complex within the cyclodextrin polymer host even though the captured guest is covalently tethered to the host periphery.

Cyclodextrin derivatives are disclosed in U. S. Pat. No. 3,426,011, Parmerter et al., issued Feb. 4,1969; U. S. Pat. Nos. 3,453,257,3,453,258,3,453,259, and 3,453,260, all in the names of Parmerter, et al., and all also issued Jul. 1,1969; U. S. Pat. No. 3,459,731, Gramera, et al., issued Aug. 5,1969; U. S. Pat. No. 3,553,191, Parmerter, et al., issued Jan. 5,1971; U. S.

Pat. No. 3,565,887, Parmerter, et al., issued Feb. 23,1971; U. S. Pat. No. 4,535,152, Szejtli, et al., issued Aug. 13,1985; U. S. Pat. No. 4,616,008, Hirai, et al., issued Oct. 7,1986; U. S. Pat.

No. 4,638,058, Brandt, et al., issued Jan. 20,1987; U. S. Pat. No. 4,746,734, Tsuchiyama, et al., issued May 24,1988; and U. S. Pat. No. 4,678,598, Ogino, et al., issued Jul. 7,1987, all of the above patents are incorporated herein by reference.

In another embodiment the capturing is accomplished through complete physical entrapment by the water soluble (or colloidal) CD polymer carrier. In this embodiment, "completely entrapped"means that a captured guest is not covalently coupled to the polymer but is entrapped within the covalently cross-linked polymer of cyclodextrin molecules so that it cannot leave the polymer by diffusion or extraction. Completely entrapped guests cannot escape until the polymer itself has been degraded or the covalent cross-link bonds are cleaved.

In this embodiment, essentially all possible exit routes for the guest to leave the polymer have been closed by cross-linking. Therefore, additional guest molecules (of that size or larger), cannot enter the closed polymer to be added to the cyclodextrin polymer carrier. In yet another embodiment, the aroma is"controlled release"--the release of a captured guest from the CD polymer carrier only by cleavage of certain linkages that were used to synthesize the carrier.

In addition to cyclodextrins, an effective amount of various additional adjunct aroma controlling materials may be incorporated. Incorporating adjunct aroma-controlling materials may enhance cyclodextrin's capacity for controlling the release of aromas. Such materials include, for example, zeolites, activated carbon, kieselguhr, and water-soluble antibacterial compounds, such as cetyl pyridinium chloride, zinc chloride, copper salts, copper ions, chlorhexidine, quaternary ammonium compounds, chelating agents, parabens, chitin, pH buffered materials, and the like.

The host/inclusion complexes of this invention may be formed in any of the ways known in the art. Typically, the complexes are formed either by bringing the host (e. g. desired aroma material or oxygen absorber) and the cyclodextrin together in a suitable solvent, e. g., water, or, preferably, by kneading/slurrying the ingredients together in the presence of a suitable, preferably minimal, amount of solvent, preferably water. The kneading/slurrying method is particularly desirable because it results in smaller particles so that there is less, or no, need to reduce the particle size. In addition, less solvent is needed and therefore less separation of the solvent is required. Disclosures of complex formation can be found in Atwood, J. L., J.

E. D. Davies & D. D. MacNichol, (Ed.): Inclusion Compounds, Vol. III, Academic Press (1984), especially Chapter 11, Atwood, J. L. and J. E. D. Davies (Ed.): Proceedings of the Second International Symposium of Cyclodextrins Tokyo, Japan, (July, 1984), and J. Szejtli, Cyclodextrin Technology, Kluwer Academic Publishers (1988). The publications are hereby incorporated herein by reference.

In another embodiment, mixtures of cyclodextrins may be combined to provide a mixture of complexes. Such mixtures, e. g., can provide more even aroma profiles by encapsulating a wider range of active ingredients and/or preventing reforming large crystals of said complexes. Mixtures of cyclodextrins can conveniently be obtained by using intermediate products from known processes for the preparation of cyclodextrins including those processes described in U. S. Pat. No.: 3,425,910, Armbruster et al., issued Feb. 4,1969; U. S. Pat. No.

3,812,011, Okada et al., issued May 21,1974; U. S. Pat. No. 4,317,881, Yagi et al., issued Mar.

2,1982; U. S. Pat. No. 4,418,144, Okada et al., issued Nov. 29,1983; and U. S. Pat. No.

4,738,923, Ammeraal, issued Apr. 19,1988, all of said patents being incorporated herein by reference. In one embodiment of the present invention where oxygen scavenging and/or absorbing is required, the"host"complex may be an oxygen scavenger. In another embodiment, the oxygen scavenger should exist as a solid at forming temperatures. In one example, the induction seal containing the oxygen scanvenger should absorb oxygen at a rate faster than the permeability of oxygen through the packaging wall for the planned shelf-life of the packaged product while having enough capacity to remove oxygen from within the package cavity if necessary.

On example of a suitable oxygen scavenger is a particulate oxygen absorbing composition containing metallic iron as a main component for an oxygen absorbing reaction.

As the metallic iron, an iron powder which has been used in an iron powder type deoxidizing agent can be used, and examples of the usable iron powder include iron powders such as a reducing iron powder and a spray iron powder, ground iron materials of a steel material or a cast iron, and an iron powder such as a ground product. In one example, the average particle diameter of the iron powder is selected in the range of 1 to 50 microns. Another component of the particulate oxygen absorbing composition containing the metallic iron may be a metal halide including chlorides, bromides and iodides of alkali metals and alkaline earth metals. The amount of the metal halide to be blended is based on the amount of metallic iron.

In another embodiment, the oxygen scavenger can be a metal powder such as iron, low valence metal oxides or reducing metal compounds. The oxygen scavenger can be used in combination with an assistant compound such as a hydroxide, carbonate, sulfite, thiosulfite, tertiary phosphate, secondary phosphate, organic acid salt or halide of an alkali metal or alkaline earth metal. The water absorbing agent can be an inorganic salt such as sodium chloride, calcium chloride, zinc chloride, ammonium chloride, ammonium sulfate, sodium sulfate, magnesium sulfate, disodium hydrogenphosphate, sodium dihydrogenphosphate, potassium carbonate or sodium nitrate.

In another embodiment, the inclusion compound may be used with a material that acts as an oxygen scavenger and/or that prevents off-flavors due to the presence of aldehydes. A wide variety of tocopherol compounds can be used. The compound dl-alpha-tocopherol, also known as vitamin E, is structurally identified as 2,5,7,8-tetramethyl-2- (4', 8', 12'- trimethyltridecyl)-6-chromanol. Other tocopherol compounds include not only the stereo- specific isomers of alpha-tocopherol but also beta-tocopherol, i. e., 2,5,8-trimethyl-2- (4', 8', 12'- trimethyltridecyl)-6-chromanol, gamma-tocopherol, i. e., 2,7,8-trimethyl-2- (4', 8', 12'- trimethyltridecyl)-6-chromanol, and 6-tocopherol, i. e., 2,8-dimethyl-2- (4', 8', 12'- trimethyltridecyl)-6-chromanol that may also be used in accordance with the present invention.

In one embodiment, component B may be a hydrophilic agent. In various embodiments, component C's loading level can range from about 5 to 10%, 10% to 20%, 20% to 40%, 40% to 60% and 60% to 75% by weight with respect to component A. With respect to component B, for example, component B's loading level can range from about 3% to 5%, 5% to 8%, 8% to 12%, 12% to 15%, 15% to 25% and 25% to 30% by weight with respect to component A.

For example, one method of forming the composition of the present invention is by adding component C and component B to component A, which in one example is a water- insoluble polymer, when component A is in a molten state; or before component A is in the molten state, so that components B and C may be blended throughout component A. For example, such a technique may be useful when components A, B and C are all powders. In another embodiment, component B (such as a hydrophilic agent) and component A are mixed prior to adding component C. Component B is either added before component A is in the molten state or after component A is in the molten state. For example, component C may be added to component A during the thermal process of forming sheets. After blending and processing, component B is drawn out into interconnecting channels that contain a percolation path in component A. The majority of component C resides in the interconnecting channels because of its preferential affinity towards component B over component A. In addition, the composition of the present invention may be described as"monolithic"because the composition does not consist of two or more discrete macroscopic layers.

For purposes of the present invention, the term"phase"means a portion of a physical system that is uniform throughout, has defined boundaries and, in principle, can be separated physically from other phases. The term"water-insoluble polymer"means a polymer having a solubility in water below about 0.1% at 25°C and atmospheric pressure. The term"hydrophilic agent"is defined as a material that is not cross-linked and that has a solubility in water of at least about I % at 25°C and atmospheric pressure. Suitable hydrophilic agents include "channeling"agents. The term"melting point"is defined as the first order transition point of the material determined by DSC. The term"not mutually soluble"means immiscible with each other. The term"immiscibility"means that the components of the blend are driven by thermodynamic forces to separate (i. e. demix) into two or more distinct phases that will coexist indefinitely under equilibrium conditions. An example is the separation of the oil-rich and water-rich phases in a salad dressing. For purposes of the present invention,"partial" immiscibility or"partial"miscibility is deemed"immiscible"and thus, any tendency for a component to phase separate from another component is deemed"immiscible."Immiscibility may be determined by the application of one or more forms of microscopy (e. g., optical, TEM, SEM or AFM) with an observation that the components are separated into two or more distinct phases. The term"particle"means a dispersed component that is either a crystalline or amorphous solid, or a crosslinked organic or inorganic material, and that retains its shape, aside from recoverable deformations, before, during, and after the blend is compounded in the molten state at elevated temperatures. This would include, e. g., a crosslinked polymer latex.

Further, for purposes of the present invention, the term"co-continuous interconnecting channel morphology"means that the minor phase (i. e., component B) is drawn out into interconnected channels that contain a percolation path, while simultaneously, the majority phase (i. e., component A) is percolating."Percolation"means that there exists at least one unbroken path, composed only of points from within that phase, that will lead from any surface of a sample through the interior of the sample to any other surface. Such a percolation path provides a route for a desired object, such as a small molecule, an atom, an ion, or an electron, to be macroscopically transported across the sample while contacting only one of the phases.

For some systems, the existence of an interconnecting channel morphology that is co- continuous may be determined by a minimum of two transport measurements that demonstrate percolation in both minor and major phases. Percolation theory is a mature branch of mathematics and physical science that is described in a variety of review articles, specialized monographs, and many introductory texts on stochastic processes, probability theory, and statistical mechanics. For example, an introductory treatment of percolation theory is described by D. Stauffer in Introduction to Percolatiora Tlzeory, Taylor and Francis, (London 1985).

The term"preferential affinity"means that the particle (i. e., component C) has a lower interfacial energy when contacting one component than compared to contacting another component. A suitable method for determining"preferential affinity"for the present invention is the following: (a) Blend the particle with the two components at elevated temperatures in their liquid state. Mix to achieve a macroscopically homogeneous dispersion.

(b) Cool the mixture and allow to solidify.

(c) Use a form of microscopy (e. g., TEM, SEM, and/or AFM) on a thin section to determine which of the two phases most closely contacts each particle in the field of view.

(d) The component that is in the majority in the phase that contacts the largest number of particles is the component with"preferential affinity"for the particle.

Further, the term"shear modulus"is the ratio of a measured shear stress to the magnitude of a small, elastically recoverable, shear strain that is used to produce that stress.

The criterion of greater than about 8 MPa refers to the shear modulus measured at room temperature. The"shear modulus"is determined by ASTM test method E143-87 (1998). The term"polymer"means a composition that is made by reacting two or more molecular species ("monomers") to form chemically-bonded larger molecules. The term"semicrystalline"means that the polymeric component, at ambient temperature, contains regions in which chain segments are packed with spatial registry into a periodic lattice and these regions are of sufficient size and extent to exhibit a detectable melting endotherm in a differential scanning calorimetry (DSC) measurement. The term"amorphous"means that the polymeric component, at ambient temperature, either contains no regions of periodic packing of segments, or such regions are undetectable with a DSC measurement.

In one embodiment, component B may be a hydrophilic agent. Suitable hydrophilic agents of the present invention may include polyglycols such as poly (ethylene glycol) and poly (propylene glycol) and mixtures thereof. Other suitable materials may include EVOH, pentaerithritol, PVOH, polyvinylpyrollidine, vinylpyrollidone or poly (N-methyl pyrollidone), and saccharide based compounds such as glucose, fructose, and their alcohols, mannitol, dextrin, and hydrolized starch being suitable for the purposes of the present invention since they are hydrophilic compounds.

In another embodiment, suitable hydrophilic agents of the present invention may also include any hydrophilic material wherein, during processing, the hydrophilic agent is heated above its melt point upon melt mixing, and subsequently upon cooling separates from the polymer to form the interconnecting channeled structure of the present invention and a three phase system of a water-insoluble polymer, hydrophilic agent and an absorbing material.

It is believed that the higher the absorbing material (i. e component C) concentration in the mixture, the greater the absorption capacity will be of the final composition. However, the higher absorbing material concentration should cause the body to be more brittle and the mixture to be more difficult to either thermally form, extrude or injection mold. In one embodiment, the absorbing material loading level can range from 10% to 20%, 20% to 40% and 40% to 60% by weight with respect to the polymer (i. e. component A).

In a further embodiment, the particle containing the desired amount and desired type of aroma may be activated by one or more specific activators such as an acid, basic, heat, IR, UV, microwave, light, pressure, and/or agitation.

With respect to component A, in one embodiment, component A may be a water- insoluble polymer such as a thermoplastic material. Examples of suitable thermoplastic materials may include polyolefins such as polypropylene and polyethylene, polyisoprene, polybutadiene, polybutene, polysiloxane, polycarbonates, polyamides, ethylene-vinyl acetate copolymers, ethylene-methacrylate copolymer, poly (vinyl chloride), polystyrene, polyesters, polyanhydrides, polyacrylianitrile, polysulfones, polyacrylic ester, acrylic, polyurethane and polyacetal, or copolymers or mixtures thereof.

In an additional embodiment, component B may be a hydrophobic agent. For purposes of the present invention, the term"hydrophobic agent"is defined as a material that has a solubility in water of less than about 20% at 25°C and atmospheric pressure.

In yet another embodiment, components A, B and C are first dry mixed in a mixer such as a Henschel, and then fed to a compounder. A Leistritz twin screw extruder, for example, or a Werner Pfleider mixer can be used to achieve a good melt mix at about 140°C to about 170°C. The melt can then be either extruded to form, for example, a film or converted into pellets using dry air cooling on a vibrating conveyer. The formed pellets, containing channels, can, for example, then be either injection molded, blow molded or other types of molding into bottles, pouches, containers, or co-injected with a plastic as the inside layer of a container.

In one embodiment, component C contains the inclusion compound with a"guest"or "host"compound of a desired aroma. The aroma may be included with component C by typical methods known in the art including, but not limited to, coating the particle, immersing the particle or methods of applying the flavor to the particle. The amount of aroma that is applied to the particle depends on the degree of flavor enhancement required (e. g. sweetness), the amount of retention on the particle and the efficiency of release of the aroma from the particle to the beverage, drink or food product. One example of an aroma component is juice aroma such as natural esters--orange juice aroma, grapefruit juice aroma and apple juice aroma.

Moreover, in a further embodiment, it is believed that a composition may be formed having channels composed of two discrete polymers (e. g. components B and B') with each type of channel composed of a majority of either the same particles (e. g. component C) or different particles (e. g. components C and C') where B/B'and C/C'are selected, among other characteristics, based on their preferential affinities with each other. For example, a composition may be formed, wherein: (a) component A is a semicrystalline polymer; (b) component B and B'are polymers; (c) components A, B and B'are immiscible within each other; (d) components C and C'are particles; (e) the volume fraction of component A represents at least about 34% by volume of the total volume of components A, B, B', C and C' ; (f) the preferential affinity between components B and C is greater than either between components A and C and between components B'and C; (g) the preferential affinity between components B'and C'is greater than either between components A and C'and between components B and C' ; (h) at least three phases are formed, one phase is composed of a majority of component A, the second phase is composed of a majority of component B and a majority of component C, and the third phase is composed of a majority of components B'and a majority of components C' ; and (i) at least three phases form the co-continuous interconnecting channel morphology. It is further believed that such a composition could be designed to have multiple characteristics. For example, a select channel morphology could have high oxygen moisture transmission properties with a majority of inclusion compound residing in these channels and another channel morphology within the same composition could have high aroma transmission properties with aroma agents. In addition, as another example, additional channel morphology may also be designed using additional components (e. g. components B", B"',... and C", C"'...).

In yet a further embodiment, because the composition of the present invention may typically be more brittle than component A without components B and C, the induction seal may be molded so that an interior portion of the seal is the composition of the present invention while the exterior portions are formed from pure polymer or the composition of the present invention with a lower loading level components B and/or C. For example, an induction seal having an interior portion composed of the composition of the present invention and an exterior portion composed of pure polymer typically will not only be more durable and less brittle, but it will also act as a gas barrier that resists the transmission of the vapor from the exterior into the interior of the package. In this manner, the absorption and/or releasing capacity of component C is potentiated by exposing it exclusively to the interior of the package from which it is desired that the vapor be withdrawn and retained therefrom.