MXPA06001315A - Peelable/resealable packaging film - Google Patents

Abstract

The present invention describes a multilayer film suitable for use in packaging applications comprising at least a polymeric first layer having a first surface and an opposing second surface wherein the polymeric first layer comprises a heat-sealable, water-insoluble polyester;a polymeric second layer having a first surface and an opposing second surface and comprising a pressure-sensitive adhesive, wherein the second surface of the polymeric second layer is in contact with the first surface of the polymeric first layer and forms a peelable/resealable bond therebetween;and a third layer in contact with the first surface of the polymeric second layer.

Description

PACKABLE / RESELLABLE PACKAGING FILM FIELD OF THE INVENTION The present invention relates generally to multilayer films for packaging applications, and particularly, to multilayer films for packaging applications having at least one peelable and resealable interlayer interface.

BACKGROUND OF THE INVENTION As is known in the art, packaging films incorporating a sealing area having a peelable and resealable film interface provide the consumer with easy means both to open a container without having to break the package and to re-close the container as often as necessary. In general, peelable / resealable film interfaces are formed when two film surfaces are bonded or sealed to one another during the package manufacturing process. This sealing or bonding area is considered "peelable" if the consumer simply grabs a portion of the film and pulls or "peels" it away from a second portion thereby causing at least two adjacent film layers to delaminate and expose the film. surface of each layer. The initial force needed to separate the layers is relatively strong before the package is opened so that the sealing area resists the expected abuse during the packaging, dispensing, and storage operation. In contrast, after the package has been initially opened, the peel force required to break the seal and re-open the package is relatively weak afterwards. In addition, the joint is considered "resealable" if the consumer simply engages the two exposed surfaces of film together thereby causing the seal between the layers to re-establish. Generally, the force required to "re-seal" the two exposed surfaces is proportional to the pressure exerted on the sealing or binding area by the consumer. The means forming the peelable / resealable bonds and their use in packaging applications are disclosed in the art. U.S. Pat. No. 6,777,050 to Engelaere discloses a cover for food containers comprising a backing layer, a pressure sensitive adhesive layer, and a breakable-heat sealable layer. The breakable-heat-sealable layer is made of metallocene-catalyzed polyethylene or polyethylene and the pressure-sensitive adhesive layer is formed of polyurethane. U.S. Pat. No. 5,089,320 for Strauss et al. discloses a packaging material consisting of a substrate layer of polyethylene terephthalate or high density polyethylene, an adhesive layer comprising a sticky adhesive, and a thermosetting layer of polystyrene, polyvinylidene chloride, or onomer. The delamination of the packaging material can occur either between the substrate or adhesive layers or the adhesive and heat sealable layers.

U.S. Pat. U U. No. 4,786, 1 90 for Van Erden e al. discloses a bag having a pressure-sensitive adhesive strip secured to the inner surface of a flap which covers the mouth of the bag. When the flap is folded over the mouth in the bag, it can be peelably secured to an outer surface of the bag. U.S. Pat. No. 4,673,601 for Lamping eí al. describes a film for sealing a container comprising a layer containing polyester, polyamide, polyvinyl chloride, biaxially oriented polypropylene, regenerated cellulose, aluminum, or paper, an adhesive layer of ethylene / vinyl acetate copolymer, styrene block copolymer / butadiene / styrene, styrene / isoprene / styrene block copolymer, or polyacrylate, and a covering layer of polyethylene, polypropylene, polyamide, polyvinyl chloride, customer melts, regenerated paper, aluminum or cellulose. The film will be delaminated at the cover layer / adhesive layer interface. U.S. Pat. No. 3,454,210 for Spiegel et al. discloses a covering film for the packaging of containers having a polyethylene layer, a layer of pressure sensitive adhesive, and a breakable layer of polyethylene. U.S. Pat. UU No.3, 329, 331 for Morgan discloses a laminate for the manufacture of resealable containers. The laminate comprises a paper base material, a lacquer coating on the base material, a pressure sensitive adhesive, and a surface sheet of either paper or plastic. The pressure-sensitive adhesive is adhered in a releasable and resealable way to the coating of lacquer on the base material. There is still a need in the packaging industry for a peel / resealable film having improved functionality. Such a film will provide a peel / resealable joint or inter-layer interface that will allow the consumer to easily open and reseal a package formed by this film as often as desired. Ideally, such a film will allow the peelable / resealable bond to open to a predetermined initial peel strength and re-open to a different and second predetermined peel force. The present invention supplies such a peelable / resealable film.

BRIEF DESCRIPTION OF THE INVENTION This present invention relates to packaging films comprising a plurality of layers having at least one polymeric first layer, a second polymeric layer, and a third layer, which may be particularly convenient for food packaging applications. . It has been discovered that the peelable / re-seal functionality can be produced in films where the first polymeric layer and the second polymeric layer each have a predetermined composition and when the second polymeric layer can be positioned in contact with the first and third layers . Accordingly, the first polymeric layer may be a recondite layer of outer film which may include a first surface and a second opposing surface and which may comprise a water-insoluble, heat-sealable polyester. The second polymeric layer may be an inner film layer having a first surface and a second opposing surface which may comprise a pressure sensitive adhesive. The first and second polymer layers may be co-extruded with each other so that the first polymeric layer is immediately adjacent to and in contact with the second polymeric layer. The union between the first and second polymer layers is a peel / resealable bond so that the first and second layers can be manually delaminated or re-bonded. The third layer can comprise any material such as thermoplastic, a cellulose, a metallic material or combinations thereof which can be directly bonded to the surface of the second polymeric layer. The third layer may also be co-extruded together with the first and second polymer layers. In one aspect of the multilayer films of the present invention, the water-insoluble, heat-sealable polyester of the first polymeric layer may include homopolymers and copolymers of alkyl aromatic esters, such as, for example, but not limited to , polyethylene terephthalate (PET), amorphous polyethylene terephthalate (APET), crystalline polyethylene terephthalate (CPET), glycol modified polyethylene terephthalate (PETG), and polybutylene terephthalate; terephthalate and isophthalate copolymers, such as, for example, but not limited to, polyethylene terephthalate / isophthalate copolymer; and homopolymers and copolymers of aliphatic esters such as, for example, polylactic acid (PLA) and polyhydroxyalkanoates, such as, for example, but not limited to, polyhydroxypropionate, poly (3-hydroxybutyrate) (PH3B), poly (3-hydroxyvalerate) (PH3V), poly (4-hydroxybutyrate) (PH4B), poly (4-hydroxyvalerate) (PHV), poly (5-hydroxyvalerate) (PH5V), poly (6-hydroxydecanoate) (P.H6D) and mixtures of any of these materials. In another aspect of the multilayer films of the present invention, the pressure sensitive adhesive or sticky adhesive of the second polymeric layer may comprise a first elastomeric component and a second joining component. The first elastomeric component may comprise styrene / rubber copolymers including, but not limited to, for example, polystyrene / butadiene / styrene (SBS), polystyrene / isoprene / styrene (SIS), polystyrene / ethylene-butylene / styrene (SEBS) ), and polystyrene / ethylene-propylene / styrene (SEPS), or mixtures of any of these materials. The second joining component can comprise any linker used with elastomers to form pressure sensitive adhesives. Suitable binders include, but are not limited to, hydrocarbon binders such as terpene resins, such as resins sold under the tradename of Zonatac® by Arizona Chemical Company, Jacksonville, FL, U.S. A., and petroleum hydrocarbon resins such as resins sold under the tradename Escorez® by ExxonMobil Chemical Company, Houston, TX, U.S. A. In yet another aspect of the multilayer films of the present invention, peelable / resealable functionality can be provided by the bond formed by the first surface of the first polymeric layer in direct contact with the first surface of the second polymeric layer. The second opposing surface of the first polymeric layer may be capable of self-sealing or other substrates so that the heat-sealed bonding strength may be greater than the bonding strength between the first polymeric layer and the second polymeric layer. Therefore, the second opposing surface of the second polymeric layer may also be able to be joined to the third layer so that the bond between these layers may be greater than the bonding strength between the first polymeric layer and the second polymeric layer. In yet another aspect, the junction between the first and second polymer layers can be peelable / resealable and can include at least two distinctive bonding forces that can be varied and controlled over a relatively long range, i.e. , between 0.1 Ib / inch to about 8 Ib / inch (less than 0.017 Kg / cm to about 1.38 Kg / cm.). Accordingly, the peelable / resealable bond can include both a first initial peel force and a second peel force re-set. The first initial peeling force can be characterized as the manual force required to delaminate the first polymeric layer of the second polymeric layer. Preferably, the first initial peel force may be greater than the second peel force re-set. The initial initial peel strength can be at least 2 Ib / inch (0.36 Kg / cm) as measured according to the ASTM F-904 test method when a peel / resealable joint is formed by thermo-sealing the film itself at a temperature of between 126-149 ° C or alternatively, at least 3 Ib / inch (0.54Kg / cm) as measured according to the ASTM-F904 test method when a peel / resealable bond is formed at Thermo-seal the film to itself at a temperature between 126-149 ° C. The second re-set peel force can be characterized as the manual force required to separate the first polymeric layer from the second polymeric layer after these layers have been initially laminated, delaminated and subsequently re-adhered. Preferably, the value of the second re-set peel force may be less than the value of the initial peel force. Accordingly, the second re-set peel force can be at least 0.50 Ib / inch (0.09 Kg / cm) as measured according to the ASTM F-904 test method after the peel / resealable bond is formed by thermo-sealing the film to itself at a temperature of between 126-149 ° C, manually separating the film together with the peel / resealable bond, and re-sealing the film to itself. Alternatively, the second re-set peel force can be at least 0.60 Ib / inch (0.1 1 Kg / cm) as measured according to the ASTM F-904 test method after the peel / resealable bond is formed by thermo-sealing the film to itself at a temperature of between 126-149 ° C, manually separating the film together with the peel / resealable bond, and re-sealing the film to itself. In yet another aspect, the multilayer films of the present invention can supply flexible bags, small bags, containers, lids and portions thereof which are peelable / resealable and which is an improvement over prior art packages. These and other aspects, advantages, and features of the invention will be more readily understood and appreciated by reference to the detailed description of the invention and the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partially schematic cross-sectional view of one embodiment of a multilayer film according to the present invention comprising a first polymeric layer, a second polymeric layer, and a third layer. FIG. 2 is a partially schematic cross-sectional view of one embodiment of a three-layer multilayer film according to the present invention in the form of a flexible package in a closed state. FIG. 3 is a partially schematic cross-sectional view of one embodiment of a multilayer three layer film according to the present invention in the form of a seal region of a flexible package in a partially open state. FIG. 4 is a partially schematic cross-sectional view of one embodiment of a three-layer multilayer film according to the present invention in the form of a cover membrane in a partially open state.

DETAILED DESCRIPTION OF THE INVENTION As used herein, the term "film" is generally used to include plastic netting, regardless of whether it is a film or a sheet. As used herein, the phrase "thermoplastic" refers to a polymer or polymer blend that softens when exposed to heat and returns to its original condition when cooled to room temperature. In general, thermoplastic materials include, but are not limited to, synthetic polymers such as polyester, polyamides, polyolefins, polystyrenes, and the like. The thermoplastic materials may also include any synthetic polymer that is degraded by either radiation or chemical reaction during an operation of the manufacturing or post-manufacturing process. As used herein, the term "polymeric" refers to a material that is the product of a polymerization reaction of natural, synthetic, or natural and synthetic ingredients, and is inclusive of homopolymers, copolymers, terpolymers, etc. In general, the layers of a film or substrate may comprise a single polymer, a mixture of a single polymer and non-polymeric materials, a combination of two or more polymeric materials blended together, or a mixture of a combination of two or more materials polymeric and non-polymeric materials. As used herein, the term "copolymer" refers to polymers formed by the polymerization of the reaction of at least two different monomers. For example, the term "copolymer" includes the product of the co-polymerization reaction of ethylene and an α-olefin, such as 1-hexen. The term "copolymer" is also inclusive of, for example, the co-polymerization of a mixture of ethylene, propylene, 1-butene, 1 -hexene, and 1-octane. As used herein, a copolymer identified in terms of a plurality of monomers, e.g. "ethylene / propylene copolymer" refers to a copolymer in which any monomer can be copolymerized at a higher weight or mole percentage than another monomer or monomers. However, the term "copolymer" as used herein refers to those polymers where the first listed monomer is polymerized at a higher weight percentage than the second listed monomer. As used in the present, the terminology used "/" with respect to the chemical identity of a copolymer (eg, polyvinylidene chloride / methyl acrylate copolymer), identifies the comonomers that are copolymerized to produce the copolymer. As used herein, the phrase "polyolefin" refers to homopolymers, copolymers, including ex. bipolymers, terpolymers, block copolymers, graft copolymers, having a methylene bond between monomer units which can be formed by any method known to those skilled in the art. Examples of polyolefins include polyethylene (PE) which includes, but is not limited to, low density polyethylene (LDPE), linear low density polyethylene (LLDPE), very low density polyethylene (VLDPE), ultra low density polyethylene (ULDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), ultra high density polyethylene (HDPE) UHDPE), and polyethylenes comprising. ethylene / α-olefin (E / AO) which are copolymers of ethylene with one or more α-olefins (alpha-olefins) such as butene-1, hexene-1, octene-1, or the like as a comonomer, and the like. Other examples of polyolefins include cyclic olefin copolymers (COC), ethylene / propylene copolymers (PEP), polypropylene (PP), propylene / ethylene copolymer (PPE), polyisoprene, polybutylene (PB), polybutene-1, poly-3 -methylbutene-1, poly-4-methylpentene-1, ionomers (IO), and propylene / α-olefins (P / AO) which are copolymers of propylene with one or more α-olefins (alpha-olefins) such as butene- 1, hexene-1, octene-1, or the like as a comonomer, and the like. As used herein, the term "polyester" refers to homopolymers or copolymers having an ester linkage between monomer units that can be formed, for example, by condensation polymerization reactions between a dicarboxylic acid and a glycol. The ester can be represented by the general formula: [RC (O) O-R '] n wherein R and R' = alkyl group and can be generally formed by the polymerization of dicarboxylic acid and diol monomers or monomers containing both portions of carboxylic acid as of hydroxy. The dicarboxylic acid can be linear or aliphatic, i.e., oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and the like; or they may be aromatic or aromatic substituted by alkyl, that is, several isomers of etalic acid, such as paraphtalic acid (or terephthalic acid), isophthalic acid and naphthalic acid. Specific examples of alkyl-substituted aromatic acids include the various isomers of dimethylphthalic acid, such as dimethyl isophthalic acid, dimethyl dophthalic acid, dimethylterephthalic acid, the various isomers of diethylphthalic acid, such as diethylsophthalic acid, diethyldophthalic acid, the various isomers of dimethylnaphthalic acid, as 2,6-dimethylnaphthalic acid and 2,5-dimethylnaphthalic acid, and the various isomers of diethylnaphthalic acid. The glycols can be straight or branched chain. Specific examples include ethylene glycol, propylene glycol, trimethylene glycol, 1,4-butane diol, neopentyl glycol, and the like. Polyalkyl terephthalates are aromatic esters having a benzene ring with ester bonds in the 1,4-carbons of the benzene ring as compared to the polyalkyl isophthalates, wherein two ester bonds are present in the 1,3-carbons of the benzene ring. In contrast, the polyalkyl naphthalates are aromatic esters having two fused benzene rings where the two ester bonds can be present in the 2,3-carbons or the 1,6-carbons. An example of a commercial copolyester suitable for use with the present invention is Kodabond 51 16 manufactured by Eastman Chemical Company, Kingsport, TN, USA. As used herein, the terms "polylactic acid" and "polylactide" are used as synonyms throughout this description to describe homopolymers or copolymers having an ester linkage between monomer units and may be represented by the general formula: [ -OCH (R) C (O) -] n where R = CH3. Polylactic acid can be manufactured by the polymerization of lactic acid, which is mostly produced from the carbohydrate fermentation of corn. Polylactic acid can also be produced by the polymerization of lactide which is obtained from the condensation of two molecules of lactic acid. Polylactic acid has a vitreous transition temperature of ranges of 50-80 ° C while the melting temperature varies from 130-180 ° C. Polylactic acid is known to those skilled in the art and fully disclosed in US patents. Nos. 5,698,322; 5, 142.023; 5,760, 144; 5,593,778; 5,807,973; and 5,010, 145, the full disclosure of each is incorporated herein by reference. Examples of commercially available polylactic acid are sold under the trademark of NatureWorks ™ PLA Polymer in grades 4031-D, 4032-D, and 4041-D from Cargill Dow LLC, Minneapolis, MN, USA. UU As used herein, the term "polyhydroxyalkonates" refers to polyesters having a 3-hydroxy alkoxide moiety on the polymer column. Polyhydroxyalconates are semi-crystalline thermoplastic polyesters which are insoluble in water and can be represented by the general formula: [-OCH (R) - (CH2) xC (O) -] n where x = 1 -3 and R = H or CmH2m +? , where m = 1 -1 1. Examples of commercially available polyhydroxyalkonones are sold by Metabolix, Cambridge, MA, USA. As used herein, the term "polyamide" refers to homopolymers or copolymers having an amide bond between monomer units which may be formed by any method known to those skilled in the art. Useful polyamide homopolymers include nylon 6 (polycaprolactam), nylon 1 1 (polyundecanolactam), nylon 12 (polylaurylactam), and the like. Other useful polyamide homopolymers also include nylon 4.2 (polytetramethylene ethylenediamide), nylon 4,6 (polytetramethylene adipamide), nylon 6,6 (polyhexamethylene adipamide), nylon 6,9 (polyhexamethylene azelamide), nylon 6,10 (polyhexamethylene sebamide) ), nylon 6.12 (polyhexamethylene dodecanediamide), nylon 7.7 (polyheptamethylene pimelamide), nylon 8.8 (polyoctamethylene sumide), nylon 9.9 (polynonamethylene azelamide), nylon 10.9 (polydecamethylene azelamide) nylon 12, 12 (polidodecamethylene dodecanediamide), and the like. Useful polyamide copolymers include nylon 6,6 / 6 copolymer (polyhexamethylene adipamide / caprolactam copolymer), nylon 6 / 6,6 copolymer (polycaprolactam / hexamethylene adipamide copolymer), nylon 6.2 / 6.2 copolymer copolymer (polhexamethylene ethylenediamide / hexamethylene ethylenediamide copolymer), nylon 6,6 / 6,9 / 6 copolymer (polyhexamethylene adipamide / hexamethylene azelaamide / caprolactam copolymer), as well as other nylon which are not particularly delineated herein. Examples of even more convenient polyamides include nylon 4, 1, nylon 6, 1, nylon 6,6 / 6 copolymer! , 6,6 / 6T nylon copolymer, MXD6 (poly-m-xylylene adipamide), 6T / 6I nylon copolymer, nylon 6 / MXDT / l copolymer, MXDI nylon, poly-p-xylylene adipamide, polyhexamethylene terephthalamide, polidodecamethylene terephthalamide and the like. As used herein, the term "polystyrene" refers to homopolymers and copolymers having at least one linkage of styrene monomer (benzene having an ethylene substitute) within the repeating column of the polymer. The styrene linkage can be represented by the general formula: [(C6R5) CH2CH2] n wherein R = H or an alkyl group. The polystyrene can be formed by any method known to those skilled in the art. Suitable polystyrene resins include, for example, but not limited to, polystyrene (PS), oriented polystyrene (OPS), syndiotactic polystyrene (SPS), acrylonitrile-butadiene-styrene (ABS), styrene-acrylonitrile (SAN), copolymers of ethylene / styrene, styrene / acrylic copolymers, styrene block copolymers (SBC), and the like. As used herein, the phrase "styrene / rubcopolymer" refers to block copolymers including diblock, tri-block, radial block, multi-block and mixtures thereof of styrene and rub Suitable rubsegments of rub/ styrene rubcopolymers may include, but are not limited to, butadiene, isoprene, butylene, ethylene-butylene, propylene, ethylene-propylene, ethylene, and mixtures thereof. Exemplary styrene / rubcopolymers which are commercially available include styrene / rubcopolymers sold under the tradename Kraton® by Kraton Polymers, Houston, TX, USA. UU Styrene / rubcopolymers are fully disclosed in U.S. Pat. No. 5,221, 534, the disclosure which is incorporated herein by reference. As used herein, the term "binder" is generally an adhesive additive that serves to modify the rheological properties of the final adhesive. Specifically, a bonding resin to improve the tackiness of the adhesive composition. As used herein, the term "tackiness" refers to the "adhesiveness" of the adhesive or its resistance to stirring or deformation of a substrate. The linker may comprise any suitable material, preferably, a hydrocarbon resin material or mixtures thereof. Exemplary binders are Escorez®1 102, Escorez®1304, Escorez®1315, available from ExxonMobil Chemical Company, Houston, TX, USA.; Wingtak® resins available from Goodyear Chemicals, Akron, OH, USA; Piccotac®1 100 and Polipale®1 00 available from Eastman Chamicals, Kingsport, TN, USA. UU As used herein, the phrase "metallic material" as applied to the film layers refers to a metal and / or metal oxide that may be present in such a form as a metal foil or metal coating. Suitable metals and metal oxides may include, but are not limited to, aluminum, aluminum oxide, zinc, zinc oxide, nickel, nickel oxide, copper, copper oxide, silver, silver oxide, and mixtures thereof. As used herein, the phrase "cellulosic material" as applied to film layers refers to any natural or synthetic material comprising paper fibers, wood fibers, wood pulp or powder and the like. As used herein, the term "coextrusion" refers to the process of extruding two or more materials through a single mold with two or more orifices arranged so that the extrudates exit and melt together in a laminar structure before cool down, ex. , by turning off. Coextrusion can be used in blown film, mold film, and extrusion coating. As used herein, the phrase "peel strength" refers to the bond or adhesive force between the outermost, heat-sealable, film layer and the adjacent adhesive layer and therefore depends primarily on the chemical similarity or the dissimilarity of the materials that form the two layers. The peel strength of known materials can also be affected by the production conditions, conditions of the packaging machine, and environmental conditions during the manufacture of the film, the packaging and storage process. The multilayer film according to the present invention can be heat sealed to itself in such a way that the two portions of the innermost outer layer are brought into contact with each other using the heat sealing jaws and applying a pressure ( force) of 30 psi for 1 second at a temperature between 126-149 ° C. The innermost, outer layer can then be separated or delaminated from an adjacent adhesive layer (a second polymeric layer) and the force required to separate these layers can be measured according to the ASM F-904 test method. This is referred to as "the first initial peeling force". After delamination, the separated portions of film can be manually gathered by the application of a manual force to this sealing region of the film. The innermost, outer layer may be re-separated further or delaminated from an adjacent adhesive layer (second polymeric layer) and. The force required to separate these layers can be measured according to the ASM F-904 test method. This is referred to as the "second re-sticking peel force". As used herein, the phrase "peel / reseal bond" as used. herein refers to at least one joint between the two adjacent layers of film that is adapted to be easily separated or delaminated by manual separation of the film, and re-sealed or re-adhered to itself by the joining of the two portions separated from each other by means of manual pressure application. As used herein, the terms "heat seal", "heat seal", "heat seal" and the like refer to a first portion of a surface of the film (i.e., formed of a single layer or multiple layers) which is capable of forming a fusion bond with a second portion of a surface of the film. A heat-sealed layer is capable of melt-bonding by conventional indirect heating means that generate sufficient heat on at least one contact surface of the film for conduction to the contact surface of the adjacent film and the formation of an interface of union between them without losing the integrity of the film. It should be recognized that the heat seal can be carried out by any one or more of a wide variety of ways, such as using a heat-sealing technique (eg, bead sealing by melting, thermal sealing, impulse sealing, ultrasonic sealing, hot air, hot wire, infrared radiation, eic). As used herein, the phrase "innermost, outermost film layer" as applied to the film layers of the present invention refers to the outermost layer of film that is closest to the product relative to the other outermost layers of the film. the multilayer film. A more internal, outer layer can serve as a layer of contact with food. The phrase "outer film" as applied to the film layers refers to any layer having less than two of its principal surfaces directly adhered to another layer of film. In contrast, the phrase "outermost film layer," as used herein, refers to the outermost film layer that is farthest from the product relative to the top of the other layers of the multilayer film. As used herein, the phrase "inner film layer" as applied to the film layers refers to any film layer having both of its principal surfaces directly adhered to another layer of film. As used herein, the phrase "food contact layer" as applied to the film layers refers to any layer of multilayer film that is in direct contact with the food product packaged in the film. As used herein, the phrase "pressure sensitive adhesive" refers to adhesives that are sticky in the application of pressure without their tack being essentially dependent on the rise in temperature. As used herein, the term "water-insoluble" as applied to polymeric materials used in the formation of one or more layers of film refers to those polymeric materials that are not soluble in water. As used herein, the phrase "direct contact" as applied to the film layers, is defined as adhesion of the surface of the film layer attached to another surface of the film layer (presumably, full flat surfaces).

The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention can, however, be incorporated in many different forms and should not be taken into account as limiting the embodiments provided herein; although, these modalities are provided so that disclosure is complete and direct and fully transmits the scope of the invention to those skilled in the art. Similar numbers refer to similar elements throughout the document. FIG. 1 is a cross-sectional schematic diagram of one embodiment of a multilayer film according to the present invention. An embodiment of the inventive film 10 comprising at least a first polymeric layer 11, a second polymeric layer 12, and a third layer 13 is described. The first polymeric layer 11 may include a first surface 11 a and a second opposing surface 11 b such that the first surface 11 a may be in direct contact with the second polymer layer 12. The first polymer layer 11 may be a more internal, outer film layer that can form an inner, outer film 50 surface of film 10. The materials Suitable for use in the first polymeric layer 11 may include homopolymers and copolymers of alkyl aromatic esters, such as, for example, but not limited to, polyethylene terephthalate (PET), amorphous polyethylene terephthalate (APET), polyethylene terephthalate. crystalline (CPET), glycol modified polyethylene terephthalate (PETG), and polybutylene terphthalate; terephthalate and isophthalate copolymers, such as, for example, but not limited to, polyethylene terephthalate / isophthalate copolymer; and homopolymers and copolymers of aliphatic esters such as, for example, polylactic acid (PLA) and polyhydroxyalkanoates, such as, for example, but not limited to, polyhydroxypropionate, poly (3-hydroxybutyrate) (PH3B), poly (3-hydroxyvalerate) (PH3V), poly (4-hydroxybutyrate) (PH4B), po! I (4-hydroxyvalerate) (PHV), poly (5-hydroxyvalerate) (PH5V), poly (6-hydroxydecanoate) (PH6D) and mixtures of any of these materials. Preferably, the first polymer film 11 may comprise a water insoluble polyester which may include an ester selected from the group consisting of polylactic acid, polyethylene terephthalate or mixtures thereof. It will be appreciated that the first polymeric layer 11 can have any thickness of between 0.01-1.000 (0.254-254 μm), preferably, between 0.05-0.5 mil (1.227.7.7 μm), and more preferably, between 0.1- 0.3 thousand (2.54-7.62 μm). It will also be appreciated that since the first polymeric layer 11 can function as an inner, outer, and heat sealable layer, it can also serve as a food contact layer in films suitable for food packaging applications. As described, the second polymeric layer 12 may include a first surface 12a that may be in direct contact with the third layer 13, and a second opposing surface 12b that may be in direct contact with the first surface 1 1 a of the first layer polymeric 11. The second polymeric layer 12 may comprise a pressure sensitive adhesive having a first joining component and a second elastomeric component. Preferably, the second elastomeric component may comprise a styrene / rubber copolymer including, but not limited to, polymers such as, for example, polystyrene / butadiene / non-styrene (SBS), polystyrene / isoprene / styrene (SIS) , polystyrene / ethylene-butylene / styrene (SEBS), and polystyrene / ethylene-propylene / styrene (SEPS), or mixtures of any of these materials. Preferably, the styrene / rubber copolymer may include, but is not limited to, a material selected from the group consisting of butadiene, isoprene, ethylene-butylene, ethylene-propylene, or combinations thereof. As shown, the third layer 13 may be immediately adjacent to the first surface 12a of the second polymer layer 12. The third layer 13 may be an outer film layer, further outward and may form an outer surface, further outwardly. of film 10. Suitable materials for use in the third layer 13 may include any material selected from the group consisting of a thermoplastic material, a cellulosic material, a metallic material, or a combination thereof. More particularly, the third layer 13 may comprise a thermoplastic material that includes any thermoplastic, but preferably, polyolefins, polyesters, polyamides, polystyrenes or mixtures thereof, a cellulosic material, a metallic material that includes any metallic material, but preferably, lamellae metallic or metallic coatings. The first polymeric layer 11 and a second polymeric layer 12 can be co-extruded with each other. When the third layer 13 comprises a thermoplastic material, then the first polymeric layer 11, the second polymeric layer 12 and the third layer 13 can be co-extruded with each other. In any case, any conventional co-extrusion technique or combinations thereof can be used to form these layers and these methods include, but are not limited to. mold coextrusion, blown film coextrusion, extrusion lamination, coextrusion coating, and the like. Preferably, the first polymeric layer 11 and second polymer layer 12 may be co-extruded with each other using either mold coextrusion or blown film, and the first polymer layer 11, second polymer layer 12 and third layer 13 may be co-extruded with each other using mold coextrusion or blown film . It will be appreciated by those skilled in the art that the multilayer films of the present invention are not limited to three layers and may further comprise any number of additional layers as desired. FIG. 2 is a schematic cross-sectional diagram through a film according to the present invention in the form of a package. FIG. 2 is for illustrative purposes only. In this embodiment, a tubular package 20 can be formed when a first portion of film 10, layers 11, 12, 13, are joined with a second portion of film 10, 1 1 '12', 3 'and thermo-sealed to form a peel / resealable joint 53 in the region 54. In this case, the peel / resealable joint 53 of the sealing region 54 is shown in a closed state. It will be appreciated by those skilled in the art that multilayer films according to the present invention can be used to make any container, bag, package, small bag or any portion thereof and are not limited to any particular size, shape or shape. design. As described, the layer 13 (13 ') can serve as an outer film surface, more outwardly 50. Wherein, the layer 11 (11') can supply an innermost, outer film surface 51 and can also serve as a layer of contact with food. FIG. 3 is a schematic cross-sectional diagram through a film 10 illustrating the peel / resealable bond 53 of the sealing region 54 of the package 20 (see FIG 2) in a partially open state. FIG. 3 is for illustrative purposes only. To place the peel / resealable joint 53 in a partially or fully open state, the sealing region 54 can be manually grasped and separated in opposite directions. In doing so, the force exerted on the film 10 in the sealing region 54 can preferably separate the first polymeric layer 1 1 from the second polymeric layer 12. The bonding force between a first portion of the first polymeric layer 11 and a second one portion of the first polymer layer 1 1 '(formed after heat-sealing the film layers themselves) may be larger than the bonding strength between the first polymer layer 1 1 and the second polymer layer 12. Additionally, the Binding force between the second polymeric layer 12 and the third layer 13 can be greater than the bonding strength between the first polymeric layer 1 1 and the second polymeric layer 12. Accordingly, the first surface 1 1 a of a first portion of the first polymeric layer 11 may preferably be delaminated or separated from the second polymeric layer 12 and the second opposing surface 1 1 b of a first portion of the first polymeric layer 1 1 may remain egurated to the second portion of the first polymer layer 1 1 '. If the package 20 (see FIG 2) has never been opened before, the breaking force may eventually fracture the first polymeric layer 11 which can completely divide the sealing region 54 into two sections 54a and 54b (shown here in one embodiment). partially divided state). As a result, the pressure sensitive adhesive of the second polymeric layer 12 can be exposed. To re-close the package 20 (see FIG.2), it may only be necessary to place the section 54a in contact with the section 54b in such a way that the first surface 11a of the first polymer layer 11 of the section 54b is in face to face with the surface of the second polymeric layer 12 of the section 54a, and manually press them lightly with each other. The package can be easily opened and re-closed in this mode repeatedly as necessary. Therefore, the force required to reopen the package 20 (see FIG.2) by peeling the first polymer layer 11 of the second polymer layer 12 may be less than the force required to initially open the package 20 (see FIG.2). It will be appreciated by those led in the art that the peel / resealable bond 53 is not limited to any particular mechanism by which the first polymeric layer 11 can be separated from the second polymeric layer 12. Therefore, there can be a cohesion failure. wherein the adhesive of the second polymeric layer 12 fractures and the adhesive residue remains on the surface of both the first surface 1 a of a first portion of the first polymer layer 1 1 and the surface of the second polymer layer 12. Alternatively, the adhesive of the second polymeric layer 12 can be on only one of the surfaces adhered with the adhesive-free coupling surface. FIG. 4 is a cross-section schematic diagram of another embodiment of the multilayer film according to the present invention in the form of a cover membrane 55 on a rigid container 30, in a partially open state. In FIG. 4, the film 10 is not drawn to scale and is for illustrative purposes only. As described, the inventive film 10 can be heat sealed to the opening of a preformed container 30 and can then be partially or completely separated from the edge of the container 56. During the rupture / opening of the cover membrane 55, a small portion of the first polymeric layer 11"of the film 10 may be sealed to the edge of the container 56. Because the bond between the first polymeric layer 11 and the edge of the container 56 may be stronger than the junction between the first polymeric layer 11 and the second polymeric layer 12, the film 10 can be preferably broken between the first polymeric layer 1 1 and the second polymeric layer 12, thereby allowing the cover membrane 55 to be easily peeled from the container 30. The self-adhesive properties of the second polymeric layer 12 can also allow the membrane of the cover 55 to be easily re-glued to the edge of the container 56.

EXAMPLES The invention is illustrated by the following examples, which are provided for purposes of representation, and are not described as limiting the scope of the invention. Unless otherwise indicated, the thermoplastic resins used in the present invention are generally commercially available in post form and, as is generally recognized in the art, can be melt blended or mechanically mixed by well-known methods using commercially available equipment. including mixers, mixers or blenders. Also if desired, well-known additives such as processing aids, slip agents, anti-blocking agents and pigments, and mixtures thereof can be incorporated into the film, by pre-extrusion mixing. The resins and any additives are introduced into an extruder where the resins are melt-plasticized by heating and then transferred to an extrusion mold (or coextrusion) for formation in a tube. The temperatures of the mold and of the extruder will generally depend on the particular resin or resin containing mixtures being processed and the suitable temperature ranges for commercially available resins are generally known in the art, or are provided in available technical bulletins made by the manufacturers. of resins. Processing temperatures may vary depending on other processing parameters chosen. In all of the following examples, all film structures were produced using a single bubble blowing extrusion apparatus and method. The single bubble blowing film apparatus includes a multi-fold circular mold head through which the film layers are forced and formed into a cylindrical bubble of multilayer film. The bubble is off eg. , via chilled water bath, solid surface and / or air, and then finally collapsed and formed into a multilayer film. For the following examples, a single 7"diagonal represents the division between the individual layers within a film structure.

EXAMPLE 1 For Examples 1-4, the first polymeric layer comprised polyester that was dried at less than 250 ppm moisture and maintained at this moisture level during the melting process. The polyester comprised polylactic acid (PLA) having a density of 1.25 g / cm 3, a melting point of 160 ° C, a glass transition temperature of 58 ° C, a tensile strength in breaking (machine direction / direction transverse) of 15/21 kpsi, and is available under the trade name NatureWorks ™ PLA Polymer 4032-D from Cargill Dow LLC, Minneapolis, MN, USA. UU In Example 1, the second layer was an adhesive comprising a styrene block copolymer and an elastomer having a density of 0.96 g / cm 3 and is available under the tradename M3156 from Bostik Findley, Inc., Wauwatosa, Wl, EE . UU The third layer comprised a high density polyethylene (HDPE) having a density of 0.958 g / cm.3, a melt index of 0.85 g / 10min, a breaking tensile strength (machine direction / transverse direction) of 3.7 / 3.8kpsi, and is sold under the trade name of Alathon® L5885 from Equistar Chemicals; LP, Houston, TX, USA Example 1 was produced having a total film thickness of 2.5 thousand and with the following structure and layer thicknesses (% relative to the total thickness, starting with the first layer and going from left to right: 10% PLA / 25% Adhesive / 65% HDPE EXAMPLE 2 For Example 2, the first polymeric layer was identical in composition to that of Example 1. The second and third layers both comprised an adhesive comprising a styrene block copolymer and an elastomer having a density of 0.96 gl and is available under the product name M31 56 from Bostik Findley, Inc., Wauwatosa, Wl, USA. The fourth layer comprised ultra low density polyethylene (ULDPE) with a density of 0.912 g / cm3, a melt index of 1.0 g / 10min. , a breaking tensile strength (machine direction / transverse direction) of 7.1 /6.5 kpsi, a melting point of 123 ° C and sold under the trade name of Atanne® 4201 G from The Dow Chemical Company, Midland, MI , USA U U. The layers, fifth, sixth and seventh each comprise high density polyethylene (HDPE) having a density of 0.958 g / cm3, a melt index of 0.95 g / 10 min, a breaking tensile strength (direction machine / cross direction) of 7.9 / 3.4 kpsi, and is sold under the trademark of Alathon® M 6210 from Equistar Chemicals; LP, Houston, TX, USA UU Example 2 was produced having a total film thickness of 2.5 thousand and with the following structure and layer thicknesses (% relative to total thickness), starting with the first layer and going from left to right: 6.3% PLA / 14.2% Adhesive /13.1% Adhesive / 13.7% ULDPE / 14.4% HDPE / 14.4% HDPE / 24.0% HDPE EXAMPLE 3 For example 3, the first polymer layer was identical in composition to that of Example 1, and the second, and third layers, respectively, were identical in composition to those in Example 2. The fourth, fifth and sixth layers , layers each comprised high density polyethylene (HDPE) having a density of 0.958 g / cm3, a melt index of 0.85 g / 10min., a breaking tensile strength (machine direction / transverse direction) of 3.7 / 3.8 kpsi, and is sold under the trade name Alathon® L 5885 from Equistar Chemicals, LP, Houston, TX, USA. UU The seventh layer comprises ultra low density polyethylene (ULDPE) with a density of 0.91 2 g / cm3, a melt index of 1.0 g / 10 min, a tensile strength in breakage (machine direction / transverse direction) of 7.1 /6.5 kpsi, a melting point of 123 ° C, and sold under the tradename Attane® 4201 G from The Dow Chemical Company, Midland, MI, USA. UU Example 3 was produced having a total film thickness of 2.5 thousand and with the following structure and layer thicknesses (% relative to total thickness), starting with the first layer and going from left to right: 7.0% PLA / 12% Adhesive / 13% Adhesive / 15% HDPE / 14. 5% HDPE / 14.5% HDPE / 24% ULDPE EXAMPLE 4 For example 4, the first and second polymer layers were identical in composition to those used in example 1. The third layer comprised a mixture of 47.5% (p) linear low density polyethylene, 47.35% (p) ethylene / vinyl alcohol copolymer and 5.3% (p) of processing additives. Linear low density polyethylene (LLDPE) has a melting point of 121 ° C, a density of 0.918 g / cm3, a melt index of 1.0 g / 10min, a tensile strength in breakage (machine direction / transverse direction) of 6.67 / 5.37 kpsi, and is sold under the trade name ExxonMobil Escorene® LL-1 001 of ExxonMobil Chemical Company, Houston, TX, USA. UU The ethylene / vinyl alcohol (E / VA) copolymer has 12% vinyl acetate content, a melting point of 95 ° C, a density of 0.93 g / cm3, a melt index of 0.35 g / 1 min, and it is sold under the trade name! of DuPont ™ Elvax® 3135X from E. L duPont Nemours and Company, Wilmington, DE, USA. UU Example 4 was produced having a module of 54.6 Kpsi in the machine direction and 51.6 Kpsi in the transverse direction, a total film thickness of approximately 2.75 thousand and with the following structure and layer thickness (% relative to the total thickness ), starting with the first layer and going from left to right: 9.1% PLA / 18.2% Adhesive 172.7 %% (LLDPE + E / VA) EXAMPLE 5 For example 5, the first polymeric layer comprised polyethylene terephthalate (PET) having a density of 1.31% g / cm3, a tension modulus of 32 Kpsi, a breaking elongation of less than 5% which is sold under the trade name of Eastobond Copolyester 19412 from Eastman Chemical Company, Kingsport; TN, USA UU The second and third layers were identical in composition to those described in example 4. Example 5 was produced having a total film thickness of approximately 2.75 mil and with the following structure and layer thicknesses (% relative to total thickness) , starting with the first layer and going from left to right: 9.1% PET / 18.2% Adhesive 172.7 %% (LLDPE + E / VA) The invention can be further understood by reference to Table 1. Table 1 summarizes the first initial peeling forces for the peel / resealable bond in the film described in example 3. In. In each case, the peel / resealable joint was formed by thermo-sealing the film to itself using thermostatic jaws and applying pressure (force) of 30 psi for 1 second at a temperature between 126-149 ° C. The measurements were recorded according to the ASTM F-904 test method at a temperature of 23 ° C.

Table 1 First initial peel strength (Ib / inch) for peelable / resealable bond formed at various temperatures (Example 3) 127 ° C 132 ° C 138 ° C 143 ° C 149 ° C 4.6 4.8 3.7 4.2 4.4 4.5 2.9 3.7 4.2 3.5 4.5 4.1 4.4 4.0 4.1 Pro. = 4.5 Pro. = 4.0 Pro. = 4.0 Pro. = 4.1 Pro. = 4.0 The invention can be understood later by reference to Table 2. Table 2 summarizes the second peeling strength of the peelable joint / resellable in the film described in Example 3 obtained after the film was manually separated and subsequently re-sealed to itself. In each case, the peel / resealable joint was initially formed by thermo-sealing the film to itself using thermostatic jaws and applying pressure (force) of 30 psi for 1 second at a temperature between 126-149 ° C. The measurements were recorded according to the ASTM F-904 test method at a temperature of 23 ° C.

Table 2 Second peel strength of re-bonding (Ib / inch) for peel / reseable bonding (Example 3) __ 0. 75 0.93 0.84 0.64 0.92 Pro. = 0.83 The invention can be understood later by reference to Table 3. Table 3 summarizes the first initial peeling forces for the peel / resealable bond in the film described in example 4. In each case , the peel / resealable bond was formed by thermo-sealing the film to itself using thermostatic jaws by applying a pressure (force) of 30 psi for 1 second at a temperature between 126-149 ° C. The measurements were recorded according to the ASTM F-904 test method at a temperature of 23 ° C.

Table 3 First initial peel strength (Ib / inch) for peelable / resealable bond formed at various temperatures (Example 4) 127 ° C 132 ° C 138 ° C 143 ° C 149 ° C 2.3 2.9 3.0 3.4 2.6 The invention can further be understood by reference to Table 4. Table 4 summarizes the second peel forces of re-bonding for the peel / resealable bond in the film described in Example 4 obtained after the film was manually separated and subsequently re-sealed itself.

In each case, the peel / resealable joint was initially formed by thermo-sealing the film to itself using thermostatic jaws by applying a pressure (force) of 30 psi for 1 second at a temperature between 126-149 ° C . The measurements were recorded according to the ASTM F-904 test method at a temperature of 23 ° C.

Table 4 Second re-sticking peel force (Ib / inch) for peel / resealable bond (Example 4) ___ 0. 75 0.63 0.73 0.73 Pro. = 0.69 The invention can further be understood by reference to Table 5. Table 5 summarizes the initial peel forces for the peel / resealable bond in the film described in Example 5. In each case, the peel / resealable bond was formed by thermo - Seal the film to itself using thermo-seal jaws by applying a pressure (force) of 30 psi for 1 second at a temperature between 126-149 ° C. The measurements were recorded according to the ASTM F-904 test method at a temperature of 23 ° C.

Table 5 First initial peel strength (Ib / inch) for peel / resealable bond Formed at various temperatures (Example 5) 127 ° C 132 ° C 138 ° C 143 ° C 149 ° C 5.3 4.5 4.7 4.0 4.4 The invention can still be further understood by reference to Table 6. Table 6 summarizes the second peel forces of re-bonding for the peel / resealable bond in the film described in Example 5 obtained after the film was manually separated and subsequently re-sealed itself. In each case, the peel / resealable joint was initially formed by thermo-sealing the film to itself using thermostatic jaws by applying a pressure (force) of 30 psi for 1 second at a temperature between 126-149 ° C . The measurements were recorded according to the ASTM F-904 test method at a temperature of 23 ° C.

Table 6 Second re-sticking peel force (Ib / inch) for peel / resealable bond (Example 5) ___ 0. 68 0.64 0.62 0.64 Pro. = 0.64 Unless otherwise indicated, the physical properties and performance characteristics reported in this were measured by test procedures similar to the following methods. The following ASTM test procedures are incorporated herein for reference in their totals. Density ASTM D- 505 Vitreous transition temperature ASTM D-3418 melt index ASTM D-1238 Melting point ASTM D-3417 Peel strength ASTM F-904 Initial sealing temperature ATM F-88 Tensile strength ASTM D-882 Water vapor transmission rate ASTM F-1249 Many modifications and other embodiments of the invention will come to mind to those skilled in the art to which this invention pertains having the benefit of the teachings presented in the foregoing descriptions and associated drawings . ThusIt is to be understood that the invention is not to be limited to the specific embodiments disclosed and that the modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are used herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims (41)

1. CLAIMS 1. A multilayer film for packaging applications comprising: (a) at least one first polymeric layer, a second polymeric layer, and a third layer; (b) wherein said first polymer layer is a more internal, outer film layer, said second polymer layer is an inner film layer and both, first and second, polymer layers are co-extruded with each other; (c) wherein said first polymeric layer has a first surface and a second opposing surface and comprises a water-insoluble, water-insoluble polyester homopolymer or copolymer; (d) wherein said second polymeric layer has a first surface and a second opposing surface and comprises a pressure sensitive adhesive; wherein said second surface of said second polymeric layer is in direct contact with and attached to said first surface of said first polymeric layer in such a way that a peel / resealable bond is formed between said first and second polymeric layers; wherein said first surface of said second polymeric layer is in direct contact with and joined to said third layer; and (e) wherein said third layer comprises a material selected from the group consisting of a thermoplastic material, a cellulosic material, a metallic material and combinations thereof.
2. 2. A multilayer film for packaging applications comprising: (a) at least one first polymeric layer, a second polymeric layer, and a third layer; (b) wherein said first polymer layer is a more internal, outer film layer, said second polymer layer is an inner film layer and both, first and second, polymer layers are co-extruded with each other; (c) wherein said first polymeric layer has a first surface and a second opposing surface and comprises a water-insoluble, water-insoluble polyester homopolymer or copolymer; (d) wherein said second polymeric layer has a first surface and a second opposing surface and comprises a pressure sensitive adhesive; wherein said second surface of said second polymeric layer is in direct contact with and attached to said first surface of said first polymeric layer; wherein said bonding between said first polymeric layer and said second polymeric layer is adapted to comprise both an initial peeling force and a second peeling force of re-gluing; wherein said first surface of said second polymeric layer is in direct contact with and joined to said third layer; and (e) wherein said third layer comprises a material selected from the group consisting of a thermoplastic material, a cellulosic material, a metallic material and combinations thereof.
3. 3. A multilayer film for packaging applications according to claim 1 or 2, wherein said at least said first polymeric layer and said second polymeric layer are co-extruded with each other either by coextrusion of blown film or mold.
4. 4. A multilayer film for packaging applications according to claim 1 or 2, wherein said at least said first polymeric layer and said second polymeric layer and said third layer are coextruded with each other either by coextrusion of blown film or mold.
5. A multi-layer film for packaging applications according to claims 1 or 2, wherein said water-insoluble, heat-sealable polyester comprises a material selected from the group consisting of polylactic acid homopolymers and copolymers, polyhydroxyalkonates, polyalkyl terephthalates, polyalkyl isophthalates, polyalkyl naphthalates and mixtures thereof.
6. 6. A multilayer film for packaging applications according to claim 1 or 2, wherein said pressure sensitive adhesive comprises a first bonding component and a second elastomeric component of a styrene / rubber block copolymer.
7. 7. A multilayer film for packaging applications according to claims 1 or 2, wherein said pressure sensitive adhesive comprises a styrene / rubber block copolymer selected from the group consisting of butadiene, isoprene, ethylene-butylene, ethylene-propylene, and mixtures thereof.
8. A multi-layer film for packaging applications according to claims 1 or 2, wherein said peel / resealable bond has a first initial peel strength of at least 2 Ib / inch (0.36 Kg / cm) as measured in accordance with ASTM F-904.
9. A multi-layer film for packaging applications according to claims 1 or 2, wherein said peel / resealable bond has a first initial peel strength of at least 3 Ib / inch (0.54 Kg / cm) as measured in accordance with ASTM F-904.
10. A multi-layer film for packaging applications according to claims 1 or 2, wherein said peel / resealable bond has a second re-peel peel strength of at least 0.50 Ib / inch (0.09 Kg / cm) as measured from in accordance with ASTM F-904. eleven .
11. A multilayer film for packaging applications according to claims 1 or 2, wherein said peel / resealable bond has a second re-peel peel strength of at least 0.60 Ib / inch (0.1 1 Kg / cm) as measured in accordance with ASTM F-904.
12. A multi-layer film for packaging applications according to claims 1 or 2, wherein said water insoluble, water insoluble polyester comprises at least one material selected from the group consisting of homopolymers or copolymers of polylactic acid (PLA), polyethylene terephthalate (PET) and mixtures thereof.
13. 13. A multilayer film for packaging applications according to claims 1 or 2, wherein said first polymer layer has a thickness between 0.05-0.5 ml! (1 .27-1 2.7 μm).
14. A multilayer film for packaging applications according to claims 1 or 2, wherein said first polymeric layer has a thickness between 0.1-0.3 mil (2.54-7.62 μm).
15. 15. A multilayer film for packaging applications according to claim 1 or 2, wherein said first polymeric layer is a food contact layer.
16. 16. A multilayer film for packaging applications according to claim 1 or 2, wherein said thermoplastic material of said third layer comprises a polyolefin, polyester, polyamide, polystyrene, and mixtures thereof.
17. 17. A multilayer film for packaging applications according to claim 1 or 2, wherein said metallic material comprises either a metallic foil or a metallic coating.
18. 18. A multilayer film according to claim 1 or 2, wherein said film forms a container or a portion thereof.
19. 19. A co-extruded multilayer film for packaging applications comprising: (a) at least one first polymeric layer, a second polymeric layer, and a third polymeric layer; (b) wherein said first polymeric layer is an innermost, outermost film layer having a first surface and a second opposing surface and comprises a water insoluble, water-insoluble polyester selected from the group consisting of polylactic acid homopolymers and copolymers, polyhydroxyalkates, polyalkyl terephthalates, polyalkyl isophthalates, polyalkyl naphthalates and mixtures thereof; (c) wherein said second polymeric layer is an inner film layer having a first surface and a second opposing surface and comprises a pressure sensitive adhesive; wherein said second surface of said second polymeric layer is in direct contact with said first surface of said first polymeric layer and forms a peel / resealable bond between said, first and second, polymeric layers; wherein said first surface of said second polymeric layer is in direct contact with said third layer; and (d) wherein said third layer comprises a polyolefin.
20. 20. A coextruded multilayer film for packaging applications according to claim 19, wherein said film is formed by either extrusion of blown film or mold. twenty-one .
21. A coextruded multilayer film for packaging applications according to claim 19; wherein said pressure sensitive adhesive comprises a first coupling component and a second elastomeric component of a styrene / rubber block copolymer.
22. 22. A coextruded multilayer film for packaging applications according to claim 21, wherein said styrene / rubber block copolymer comprises a material selected from the group consisting of butadiene, isoprene, ethylene-butylene, ethylene-propylene, and mixtures thereof. same.
23. 23. A coextruded multilayer film for packaging applications according to claim 1, wherein said peel / resealable bond has a first initial peel strength of at least 2 Ib / inch (0.36 Kg / cm) as measured in accordance with ASTM F-904.
24. 24. A co-extruded multi-layer film for packaging applications according to claim 23, wherein said peelable / resealable bond has a first initial peel strength of at least 3 Ib / inch (0.54 Kg / cm) as measured in accordance with ASTM F-904.
25. 25. A coextruded multilayer film for packaging applications according to claim 19, wherein said peel / resealable bond has a second re-peel peel strength of at least 0.50 Ib / inch (0.09 Kg / cm) as measured in accordance with ASTM F-904.
26. 26. A coextruded multilayer film for packaging applications according to claim 25, wherein said peel / resealable bond has a second re-peel peel strength of at least 0.60 Ib / inch (0.1 1 Kg / cm) as measured in accordance with ASTM F-904.
27. 27. A coextruded multilayer film for packaging applications according to claim 1, wherein said first polymeric layer has a thickness between 0.05-0.5mil (1.227.7.7 μm).
28. 28. A coextruded multilayer film for packaging applications according to claim 27, wherein said first polymeric layer has a thickness of between 0.1-0.3 mil (2.54-7.62 μm).
29. 29. A coextruded multilayer film for packaging applications according to claim 19, wherein said first polymeric layer is a food contact layer.
30. 30. A coextruded multilayer film for packaging applications according to claim 19, wherein said film forms a container or a portion thereof.
31. 31 A coextruded multilayer film for packaging applications comprising: (a) at least one first polymeric layer, a second polymeric layer, and a third polymeric layer; (b) wherein said first polymeric layer is an innermost, outermost film layer having a first surface and a second opposing surface and comprises a water insoluble, water-insoluble polyester selected from the group consisting of polylactic acid homopolymers and copolymers, polyethylene terephthalate and mixtures thereof; (c) wherein said second polymeric layer is an inner film layer having a first surface and a second opposing surface and comprises a mixture of a first bonding component and a second elastomeric component of a styrene / rubber block copolymer; wherein said second surface of said second polymeric layer is in direct contact with said first surface of said first polymeric layer and forms a peel / resealable bond between said, first and second, polymeric layers; wherein said first surface is in direct contact with said third layer; and (d) wherein said third layer comprises a polyolefin.
32. 32. A co-extruded multi-layer film for packaging applications according to claim 31, wherein said film is formed by either coextrusion of blown film or mold.
33. 33. A coextruded multi-layer film for packaging applications according to claim 31, wherein said styrene / rubber block copolymer comprises a material selected from the group consisting of butadiene, isoprene, ethylene-butylene, ethylene-propylene, and mixtures thereof. same.
34. 34. A co-extruded multilayer film for packaging applications according to claim 31, wherein said peelable / resealable bond has a first initial peel strength of at least 2 Ib / inch (0.36 Kg / cm) as measured in accordance with ASTM F -904
35. 35. A coextruded multilayer film for packaging applications according to claim 34, wherein said peel / resealable bond has a first force starts! of peeling from a! less 3 Ib / inch (0.54 Kg / cm) as measured in accordance with ASTM F-904.
36. 36. A co-extruded multilayer film for packaging applications according to claim 31, wherein said peelable / resealable bond has a second peelable peel strength of at least 0.50 Ib / inch (0.09 Kg / cm) as measured in accordance with ASTM F-904.
37. 37. A co-extruded multi-layer film for packaging applications according to claim 36, wherein said peel / resealable bond has a second peeling strength of at least 0.60 Ib / inch (0.1 1 Kg / cm) as measured from in accordance with ASTM F-904.
38. 38. A coextruded multilayer film for packaging applications according to claim 31, wherein said first polymeric layer has a thickness between 0.05-0.5mil (1.227.7.7 μm).
39. 39. A coextruded multilayer film for packaging applications according to claim 38, wherein said first polymeric layer has a thickness between 0.1 -0.3mil (2.54-7.62 μm).
40. 40. A coextruded multilayer film for packaging applications according to claim 31, wherein said first polymeric layer is a food contact layer.
41. 41 A coextruded multilayer film for packaging applications according to claim 31, wherein said film forms a container or a portion thereof.