NZ599088B - High density polyethylene blend films - Google Patents

Abstract

ABSTRACT - 599088 The disclosure relates to film comprising (A) at least one moisture barrier layer comprising a polymer blend comprising (a) high density polyethylene in an amount from about 69 % about 90 % by weight of the blend, wherein the high density polyethylene has a melt index of at least 1.0 g/10 min and a density greater than 0.958 g/cc; (b) hydrocarbon resin in an amount from about 5 % about 30 % by weight of the blend, wherein the hydrocarbon resin comprises petroleum resins, terpene resins, styrene resins, cyclopentadiene resins, saturated alicyclic resins or blends thereof; and (c) nucleating agent in an amount from about 0.01 % to about 1 % by weight of the blend, wherein the nucleating agent comprises glycerol alkoxide salts, hexahydrophthalic acid salts, similar salts or blends thereof; and (B) at least one additional layer comprising an ionomer, a high density polyethylene, a polyester, a styrene butadiene copolymer or blends thereof; wherein the film has normalized moisture vapour transmission rate of no greater than 0.30 g-mil/100 in2/day measured at about 100 °F and 90 % external relative humidity. These films are tear-resistance and chlorine-free that have no significant sticking, forming, cutting, filling or sealing issues, which makes them suitable as packaging sheets that can be thermoformed into articles, such as trays, cups, etc., which may then be used to package food, non-food, medical and industrial products. t 1.0 g/10 min and a density greater than 0.958 g/cc; (b) hydrocarbon resin in an amount from about 5 % about 30 % by weight of the blend, wherein the hydrocarbon resin comprises petroleum resins, terpene resins, styrene resins, cyclopentadiene resins, saturated alicyclic resins or blends thereof; and (c) nucleating agent in an amount from about 0.01 % to about 1 % by weight of the blend, wherein the nucleating agent comprises glycerol alkoxide salts, hexahydrophthalic acid salts, similar salts or blends thereof; and (B) at least one additional layer comprising an ionomer, a high density polyethylene, a polyester, a styrene butadiene copolymer or blends thereof; wherein the film has normalized moisture vapour transmission rate of no greater than 0.30 g-mil/100 in2/day measured at about 100 °F and 90 % external relative humidity. These films are tear-resistance and chlorine-free that have no significant sticking, forming, cutting, filling or sealing issues, which makes them suitable as packaging sheets that can be thermoformed into articles, such as trays, cups, etc., which may then be used to package food, non-food, medical and industrial products.

Description

Patents Form 5 NZ. No.

NEW ZEALAND Patents Act 1953 COMPLETE SPECIFICATION HIGH DENSITY HYLENE BLEND FILMS We, CURWOOD, INC, a company of the United States of America of 2200 Badger , Oshkosh, Wisconsin 54903, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- (Foilowed by 1A) HIGH DENSITY POLYETHYLENE BLEND FILMS BACKGROUND OF THE INVENTION This present application relates to a packaging film, specifically a high density polyethylene (HDPE) blended with a nucleating agent and arbon resin.

Moisture protection is an important function of many packages. For example, in the cereal market, HDPE is ly used for its moisture barrier property. Film thickness is increased to match the desired level of moisture barrier, but this adds weight and cost to the package.

US 6,969,556 (which is incorporated in its entirety in this application by this reference) relates to a sheet or film which comprises at least one layer comprising a first al which is very highly crystalline polymer (preferably polypropylene of 99% or greater isotacity) er with at least one second material in an amount sufficient to improve one or more of the r properties, mechanical properties and/or optical properties 'of the sheet. The second material comprises (a) a nucleating agent; (b) a polymeric material having a ring and ball softening point from about 110° C. to about 170° C. and/or (c) a hydrogenated resin such as dicyclo-pentadiene hydrogenated resin, a hydrogenated mixed monomer resin; and/or a resin obtainable from a mixture of a-methyl styrene, indene and/or vinyl toluene monomers. -1A- US 2008/0118749 (which is incorporated in its entirety in this application by this reference) relates to r films prepared from a blend of two high density polyethylene blend ents and a high. mance organic nucleating agent. The two high density polyethylene blend components have substantially different meit indices. Large reductions. in the moisture vapor transmission rate of the film are observed in the ce of the nucleating agent when the melt s of the two blend components have a ratio of greater than 10/1.

US 6,432,496, 6,969,740, and 7,176,259 (each of which is incorporated in its entirety in this application by this reference) relate to oriented HDPE films containing arbon resins having improved moisture barrier. The effects of hydrocarbon resins in oriented films are not predictive of the effect on non-oriented films. The mechanical properties of non-oriented films are more likely to be adversely affected by additives than are oriented films. (which is incorporated in its entirety in this application by this reference) relates to polyoiefin composition blends comprising an additive composition comprising a hydrocarbon resin and a high performance nucleating agent. The nucleating agent is used to se the crystallization temperature and, therefore, decrease the amount of hydrocarbon resin needed. According to , reducing the amount of hydrocarbon resin reduces the compromising effects of the hydrocarbon resin on the film’s ical properties, WC 2010/1 04628 provides examples of polypropylene polyolefin itions.

What is needed are HDPE films with improved barrier properties without increased film thickness.

In other aspects, the application s to a sheet, ically, a chlorine-free packaging sheet with tear-resistance properties. Packaging sheets are used for many purposes. One of these many purposes includes thermoforming the sheet into articles, such as trays, cups, etc., which may then be used to package food, non-food, medical and industrial products.

One packaging sheet that is currently used for thermoforming into packaging es comprises a fully coextruded sheet with nylidene chloride (PVdC) ched between high impact polystyrene (HIPS), with ethylene vinyl acetate copolymer (EVA) used to laminate the central PVdC layer to the outer HIPS layers.

This PVdC sheet generally has no significant sticking, forming, cutting, filling or sealing issues when used for thermoforming into articles. However, it is well known that PVdC has many environmental health concerns. with chlorine as the source of many of these concerns. Both the cture and the al of PVdC produce dioxin, a highly carcinogenic chemical; and many localities do not permit a converter or packager to reprocess or landfill-dispose of packaging materials ning PVdC. As a result, chlorine-free materials may be preferred.

A chlorine-free ing sheet that is currently used comprises a fully coextruded sheet with ethylene vinyl alcohol copolymer (EVOH) sandwiched between HIPS, with high density polyethylene (HDPE) between the central EVOH tayer and the outer HIPS iayers. (See, for example, US Patent 5,972,447, pubtished February 15, 2007, which is incorporated in its entirety in this application by this reference.) Such a sheet may have a layer structure of HIPS / HDPE / EVOH / HDPE / HIPS or HIPS / tie / HDPE / tie / EVOH /tie / HDPE / tie / HIPS (where “/” is used to indicate the layer boundary). Both ures are ne-free. However, both structures are known to have significant forming and cutting issues when used for thermoforming into articles. What is needed is a chlorine-free packaging sheet that has no icant sticking, forming, cutting, filling or sealing issues when used for thermoforming into articles.

BRIEF SUMMARY OF THE INVENTION The present invention relates to a film comprising (A) at least one moisture barrier layer comprising a polymer blend comprising (a) high density polyethylene in an amount from about 69 % about 90 % by weight of the blend, wherein the high density polyethylene has a melt index of at least 1.0 g/10 min and a density r than 0.958 g/cc; (b) hydrocarbon resin in an amount from about 5 % about 30 % by weight of the blend, wherein the hydrocarbon resin comprises petroleum resins, terpene resins, styrene resins, cyclopentadiene , saturated alicyclic resins or blends thereof; and (c) nucleating agent in an amount from about 0.01 % to about 1 % by weight of the blend, wherein the nucleating agent comprises glycerol alkoxide salts, hexahydrophthalic acid salts, similar salts or blends f; and (B) at least one additional layer comprising an ionomer, a high density polyethylene, a polyester, a styrene ene copolymer or blends thereof; wherein the film has normalized moisture vapor transmission rate of no greater than 0.30 gmil /100 in2/day ed at about 100 °F and 90 % external ve humidity.

The need for HDPE films with improved barrier properties without increased film thickness is met by a non-oriented film having a moisture (followed by page 4A) barrier layer. The moisture barrier layer ses a blend of high density polyethylene, hydrocarbon resin and nucleating agent. The blend comprises from about 69 % by weight to about 90 % by weight high density polyethylene or from about 75 % by weight to about 85 % by weight high density polyethylene. The high density polyethylene has a melt index of at least 1.0 g/10 min and a density greater than 0.958 g/cc. The blend further comprises from about 5 % by weight to about 30 % by weight hydrocarbon resin or from about 5 % by weight to about 20 % by weight arbon resin or from about % by weight to about 15 % by weight hydrocarbon resin. The blend also comprises from about 0.01 % by weight to about 1 % by weight ting agent or from about 0.04% by weight to about 0.10% by weight nucleating agent. The film has normalized moisture vapor transmission rate of no greater than 0.30 100 in2/day measured at about 100 °F and 90 % external relative humidity. The nucleating agent may be a glycerol alkoxide salt, hexahydrophthalic acid salt, glycerolate salt or calcium hexahydrophthalate.

In some s, the film further comprises an oxygen barrier material, and the film has a normalized oxygen transmission rate of less than about 150 ccmil /100 - 4A - (Followed by page 5) in2/day or less than about 100 cc-mil/100 in2/day. In other aspects, the film may further comprise at least one layer comprising an ionomer, at least one layer comprising a high density hylene, at least one layer comprising a copolymer of ethylene and an ester, at least one layer comprising an ethylene vinyl acetate copolymer (EVA), at least one layer sing a styrene butadiene copolymer, or combinations of the above.

The film may have a thickness of less than 3.00 mil or less than 1.70 mil.

In yet other aspects, the film may comprise a second moisture barrier layer sing a blend. The blend comprises high density polyethylene, hydrocarbon resin and nucleating agent. The blend comprises from about 69 % by weight to about 90 % by weight high density hylene, wherein the high density polyethylene has a melt index of at least 1.0 g/10 min and a y‘greater than 0.958 g/cc. The blend r comprises from about 5 0/o by weight to about 30 % by weight hydrocarbon resin and from about 0.01 % by weight to about 1 % by weight nucleating agent. in one embodiment, a polymer blend of at least three polymers is provided. The blend comprises high density polyethylene, hydrocarbon resin and ting agent.

The blend comprises from about 69% by weight to about 90% by weight high density polyethylene or from about 75 % by weight to about 85 % by weight high density polyethylene. The high density polyethylene has a melt index of at least 1.0 g/10 min and a density greater than 0.958 9/00. The blend further comprises from about 5% by weight to about 30% by weightlhydrocarbon resin or from about 10 % by weight to about 15 % by weight hydrocarbon resin. The blend also comprises from about 0.01% by weight to about 1% by weight nucleating agent or from about 0.04% by weight to about 0.10% by weight nucleating agent.

In another embodiment, a film layer comprising a blend of high y poiyethylene, hydrocarbon resin and nucleating agent is provided. The blend comprises from about 69% by weight to about 90% by weight high density polyethylene or from about 75 % by weight to about 85 % by weight high density polyethylene, wherein the high density polyethylene has a melt index of at least 1.0 g/10 min and a density greater than 0.958 g/cc. The blend further comprises from about 5% by weight to about 30% by weight hydrocarbon resin or from about 10 % by weight to about 15 % by weight hydrocarbon resin. The blend also comprises from about 0.01% by weight to about 1% by weight nucleating agent or from about 0.04% by weight to about 0.10% by weight nucleating agent. The film layer is non-oriented and has a normalized moisture vapor transmission rate of no greater than 0.30 g-mil/1OO in2/day or no greater than 0.20 g- mil/1OO y or no r than 0.15 100 in2/day, as measured at about 100 °F and 90 % external relative ty. in still another embodiment, a packaging e comprises the non-oriented film having the moisture barrier layer as described above. in some aspects, the packaging article is a rigid article or a semi-rigid article.

The need for a ne-free packaging sheet that has no significant sticking, forming, cutting, filling or sealing issues when used for thermoforming into articles is met by a chlorine—free packaging sheet comprising a first rigid component, a second rigid component and a multilayer film. The multilayer film is positioned between the first rigid component and the second rigid component. The packaging sheet has a normalized combined tear initiation and propagation resistance in both the machine direction and the transverse ion of less than about 0.115 in*lbf/ mil energy to break and less than about 0.800 % / mil elongation as measured in accordance with ASTM D1004, and has a normalized tear propagation resistance in both the machine direction and the transverse direction of less than about 0.300 in*lbf/ mil energy to break and less than about 0.145 [bf / mil peak load as measured in accordance with ASTM D1938. Lower tear ance values are tive of an ease of cutting the packaging sheet. The first rigid component and the second rigid component may comprise various materials. The multilayer film may be of any number of multiple layers (i.e., two or more layers) and may comprise various materials.

In one embodiment, the multilayer film comprises a blown, coextruded film. In another embodiment, the multilayer film comprises an n-layer blown, coextruded tubular extrudate that is collapsed and ed upon itself to form two inner r extrudate layers and that is thermally laminated to itself at the two inner tubular extrudate layers such that the two inner tubular extrudate layers form one inner layer and a romic, 2n-1 layer film results.

In further ments, the multilayer film ses various barrier components, including but not limited to a barrier component comprising a single barrier layer, a barrier ent comprising a first barrier layer and a second barrier layer and a barrier component comprising a first r component layer, a first intermediate layer, an oxygen barrier layer, a second intermediate layer and a re barrier layer.

In another embodiment, the multilayer film comprises an oxygen barrier material and the barrier layer or layers have a normalized oxygen transmission rate of less than about 0.1 cc—mil/1 00 inz/day as measured in accordance with ASTM D3985. In a further embodiment, the multilayer film comprises a moisture barrier material and the barrier layer or layers have a normalized water vapor transmission rate of less than about 0.15 g-mil/100 inzlday as measured in accordance with ASTM F1249.

In still another embodiment, a package comprises the packaging sheet. In further embodiments, the packaging sheet may be thermoformed into various packages and n various products.

In still yet another embodiment, s s of manufacturing the packaging sheet are described. in general, the methods comprise the sequential steps of (a) adding thermoplastic resins to extruders to extrude an outer layer of an n-layer multilayer barrier film, to extrude a barrier component of the multilayer barrier film and to extrude an inner layer of the ayer barrier film, such that the barrier component is oned between the outer layer and the inner layer of the multilayer barrier film and such that the multilayer r film has a first surface and an opposing second surface; (b) heating the thermoplastic resins to form streams of melt-plastified polymers; (0) forcing the streams of melt-plastified polymers through a die having a central orifice to form a tubular extrudate having a diameter and a hollow interior; (d) expanding the diameter of the tubular extrudate by a volume of fluid entering the hollow interior via the central orifice; (e) collapsing the tubular extrudate; (f) flattening the r extrudate to form two inner r extrudate iayers; (g) attaching a first rigid ent to the first surface of the multilayer barrier film; and (h) attaching a second rigid component to the opposing second surface of the multilayer barrier film.

BRIEF DESCRIPTION OF THE DRAWINGS is a diagrammatic cross-sectional view of the general ment of the chlorine~free packaging sheet described in the present‘application. is a diagrammatic cross-sectionai view of a first embodiment of the chlorine-free packaging sheet described in the present application. is a diagrammatic cross-sectional view of a second embodiment of the chlorine-free packaging sheet described in the present application. is a mmatic cross-sectional view of a third embodiment of the ne-free packaging sheet described in the present appiication.

HS. 5 is a schematic representation of a blown film process for producing a multilayer film included in the ne-free packaging sheet described in the present ation. is a cross-sectional view of a tubular extrudate made according to the process of is a diagrammatic cross-sectional view of a non-oriented three layer film having at least one moisture barrier layer. is a diagrammatic sectional view of a non-oriented five layer film having at ieast one moisture barrier layer. is a diagrammatic cross-sectional view of a non-oriented nine layer film having at least one moisture barrier layer. is a diagrammatic cross-sectional view of a non-oriented thirteen layer film having at ieast one moisture barrier layer.

DETAILED DESCRIPTION OF THE INVENTION As used throughout this application, the term "chiorine-free" refers to rs without chlorine within the repeating backbone (i.e., chain) of the r. Such polymers may contain trace amounts of al chlorine present from a chlorine- containing catalyst (e.g., TiCI3) used to produce the polymers. Examples of chlorine- free polymers include but are not limited to ne vinyl alcohol copolymer, polyamide, polyglycolic acid and acrylonitrile-methyl acrylate copolymer. Examples of lorine- free polymers include but are not limited to polyvinyl chloride and nyiidene chloride.

As used throughout this application, the term "sheet" refers to a plastic web of any ess and is not limited to a plastic web having a thickness of greater than about 10 mil. The term “film" means a plastic web of any thickness and is not limited to a plastic web having a ess of less than about 10 mil. For convenience, this application may refer to a sheet having a thickness greater than or including a film; but the terms are not limited to such interpretation.

As used throughout this application, the term "about” refers to approximately, rounded up or down to, reasonably close to, in the vicinity of, or the like. The term “approximate” is synonymous with the term “about.” As used throughout this application, the term "component” refers to a monolayer or multilayer film sing thermoplastic resin.

As used throughout this application, the term “rigid component” refers to a component selected from the group consisting of styrenic polymer, aromatic polyester, aliphatic polyester, polypropylene homopolymer and blends of such. Examples include, but are not limited to, high impact polystyrene (HIPS), l purpose polystyrene , styrene block copolymer (880) (including but not limited to styrene butadiene copolymer (88)), polyethylene terephthalate (PET), ed polyethylene terephthalate (OPET), amorphous polyethylene terephthalate (APET), glycol-modified polyethylene thalate (PETG), polylactic acid (PLA) and blends of such.

As used throughout this application, the term "multilayer” refers to a plurality of layers in a single film ure lly in the form of a sheet or web which can be made from a polymeric material or a non-polymeric material bonded together by any conventional means known in the art (i.e., coextrusion, lamination, coating or a combination of such). The ne—free packaging sheet described in the present application comprises a multilayer film including as many layers as desired and, preferably, at least three .

As used throughout this application, the term ”tear—resistance properties” includes but is not limited to the ed tear initiation and propagation resistance in both the machine direction and the transverse (i.e., cross) direction of a sheet (as measured in accordance with ASTM D1004 and further explained below) and the tear propagation ance in both the machine direction and the transverse ion of a sheet (as measured in accordance with ASTM D1938 and further explained below).

As used throughout this application, the term "polystyrene” or “PS” refers to a homopolymer or copolymer having at least one styrene monomer linkage (such as benzene (i.e., CsH5) having an ethylene substituent) within the repeating backbone of the polymer. The styrene linkage can be represented by the general formula: [CH2 ~CH2 (C6H5)]n. Polystyrene may be formed by any method known to those skilled in the art.

As used throughout this application, the term “coextruded” refers to the process of extruding two or more polymer materials through a single die with two or more orifices arranged so that the extrudates merge and weld er into a laminar structure before ng (i.e., quenching.) 'Coextrusion methods known to a person of ordinary skill in the art include but are not limited to blown film coextrusion, slot cast coextrusion and extrusion coating. The flat die or slot cast process includes extruding polymer streams through a flat or slot die onto a chilled roll and subsequently winding the film onto a core to form a roll of film for further processing.

As used throughout this application, the term “blown film” refers to a film produced by the blown coextrusion s. In the blown coextrusion process, streams of melt-plastified polymers are forced through an annular die having a central mandrel to form a tubular extrudate. The r extrudate may be expanded to a desired wall thickness by a volume of fluid (e.g., air or other gas) entering the hollow interior of the extrudate via the mandrel, and then rapidly cooled or quenched by any of various methods known to those of skill in the art.

As used throughout this application, the term “layer” refers to a discrete film or sheet component which is nsive with the film or sheet and has a substantially uniform composition. In a monolayer film, "film, )1 il sheet” and "layer” would be synonymous.

As used throughout this application, the term "barrier" refers to any al which controls a permeable element of the film or sheet and includes but is not limited to oxygen barrier, moisture barrier, al barrier, heat barrier and odor r.

As used throughout this application, the term "tie material” refers to a polymeric material serving a primary purpose or on of adhering two surfaces to one another, presumably the planar surfaces of two film layers. A tie material adheres one film layer e to another film layer surface or one area of a film layer e to another area of the same film layer surface. The tie material may comprise any polymer, copolymer or blend of polymers having a polar group or any other polymer, lymer, copolymer or blend of polymers, including modified and unmodified polymers (such as grafted mers), which provide sufficient interlayer adhesion to adjacent layers comprising otherwise nonad hering polymers.

As used throughout this application, the term “polyester” refers to a homopoiymer or copolymer having an ester linkage between monomer units which may be formed, for example, by condensation polymerization ons n a dicarboxylic acid and a diol. The ester linkage can be represented by the general formula: C(O)-R'~ '10 C(O)]n where R and R' are the same or different alkyl (or aryl) group and may be lly formed from the polymerization of dicarboxylic acid and diol monomers containing both carboxylic acid and hydroxyl moieties. The dicarboxylic acid (including the carboxylic acid moieties) may be linear or aliphatic (e.g., lactic acid, oxalic acid, maleic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azeiaic acid, sebacic acid, and the like) or may be aromatic or alkyl substituted aromatic (e.g., various isomers of ic acid, such as paraphthalic acid (or terephthalic acid), isophthalic acid and naphthalic acid). Specific es of a useful diol include but are not limited to ethylene glycol, propylene glycol, trimethylene , 1,4-butane diol, neopentyl giycol, cyclohexane diol and the like. Polyesters may include a homopolymer or copolymer of alkyl-aromatic esters ing but not limited to polyethylene terephthalate (PET), amorphous polyethylene terephthalate (APET), crystalline poiyethylene terephthalate (CPET), glycol-modified polyethylene terephthalate (PETG) and poiybutylene terephthalate; a copolymer of terephthalate and halate including but not limited to polyethylene thalate/isophthalate copolymer; a homopolymer or copolymer of aliphatic esters including but not limited to polylactic acid (PLA); polyhydroxyalkonates including but not limited to polyhydroxypropionate, poly(3- hydroxybutyrate) , poly(3-hydroxyvalerate) , poly(4-hydroxybutyrate) (PH4B), poly(4—hydroxyvalerate) (PH4V), poly(5-hydroxyvalerate) (PHSV), poly(6— hydroxydodecanoate) (PH6D); and blends of any of these materials.

As used throughout this application, the term “anchor coat material" refers to a material that is placed n one layer and an adjacent layer to anchor one layer to another layer. It may also be referred to as an “undercoat material.” As used throughout this application, the term "polyethylene" or “PE” refers (unless indicated otherwise) to ethylene homopolymers as well as mers of ethylene with at least one alpha-olefin. The term will be used without regard to the presence or absence of substituent branch groups.

As used throughout this application, the term “high density hylene” or “HDPE" es but is not limited to both (a) homopolymers of ethylene which have densities from about 0.960 g/cm3 to about 0.970 g/cm3 and (b) copolymers of ethylene and an alpha-olefin (usually 1-butene or 1-hexene) which have densities from about 0.940 g/cm3 to about 0.958 g/cm3. HDPE includes polymers made with Ziegler or Phillips type sts and polymers made with single-site metallocene catalysts. HDPE also includes high molecular weight "polyethylenes." In contrast to HDPE, whose polymer chain has some branching, are "ultra high molecular weight poiyethylenes," which are essentially unbranched specialty polymers having a much higher molecular weight than the high molecular weight HDPE.

As used throughout this application, the term "low density polyethylene” or “LDPE” refers to branched homopolymers having densities between 0.915 g/cm3 and 0.930 g/cms, as well as mers containing polar groups resulting from copolymerization (such as with vinyl acetate or ethyl acrylate). LDPE typically contains long branches off the main chain (often termed “backbone") with alkyt substituents of two to eight carbon atoms.

As used throughout this application, the term “copolymer” refers to a polymer product obtained by the polymerization on or copolymerization of at teast two monomer species. Copoiymers may also be referred to as bipolymers. The term “copolymer” is also inclusive of the rization on of three, four or more monomer s having reaction products referred to terpolymers, quaterpolymers, etc.

As used throughout this application, the term “copolymer of ethylene and at least one alpha-olefin” refers to a modified or unmodified copolymer ed by the co- polymerization of ne and any one or more alpha-oiefins. Suitable alpha-olefins include, for e, 03 to Czo alpha-olefins such as propene, 1-butene, 1-pentene, 1- hexene, 1-octene, 1—decene and combinations of such. The co-potymerization of ethylene and an olefin may be produced by heterogeneous catalysis, such as oo— polymerization reactions with Ziegter-Natta catalysis systems, including, for example, metal halides activated by an organometallic catalyst (e.g., titanium chloride) and optionally containing magnesium chloride complexed to trialkyl aluminum.

Heterogeneous catalyzed copolymers of ethylene and an alpha-otefin may include linear low density polyethylene (LLDPE), very low density hytene (VLDPE) and ultra low density poiyethylene (ULDPE) (commercially available as, for example, DowlexTM from The Dow Chemical Company (Midland, Michigan)). Additionally, the co- polymerization of ethylene and an olefin may also be produced by homogeneous catalysis, such as co-polymerization reactions with metallocene catalysis s which include constrained ry catalysts, (e.g., monocyclopentadienyl transition-metal complexes). Homogeneous catalyzed copolymers of ne and aipha-olefin may include modified or unmodified ethylene alpha-olefin copolymers having a long-chain branched (i.e., 8-20 pendant carbons atoms) alpha-olefin co-monomer rcially available as, for example, AffinityTM and AttaneTM from The Dow Chemical Company (Midland, Michigan», linear copolymers (commercially available as, for example, TafmerTM from the Mitsui Petrochemical Corporation (Tokyo, Japan», and modified or fied ethylene olefin copolymers having a short-chain branched (i.e., 3-6 pendant carbons atoms) alpha-olefin co-monomer (commercially available as, for example, ExactTM from ExxonMobii al Company (Houston, Texas». in general, neous zed ethylene alpha-olefin copolymers may be characterized by one or more methods known to those of skill in the art, including but not limited to molecular weight distribution (MW/Mn), composition distribution breadth index (CDBI), narrow melting point range and single g point behavior.

As used throughout this application, the term "modified" refers to a al derivative, such as one having any form of anhydride functionality (e.g., anhydride of maleic acid, crotonic acid, citraconic acid, itaconic acid, fumaric acid, etc.), whether grafted onto a polymer, copolymerized with a polymer or blended with one or more polymers. The term is also inclusive of derivatives of such functionalities, such as acids, esters and metal salts derived from such.

As used throughout this application, the term ating agent” refers to an additive which forms nuclei in a polymer melt to promote the growth of crystals.

As used throughout this application, the term “hydrocarbon resin" refers to a product produced by polymerization from coal tar, petroleum and turpentine feedstocks, as defined by ISO Standard 472, ics — Vocabulary,” which is incorporated in its entirety in this ation by this reference.

As used throughout this ation, the term "intermediate layer” refers to a layer that is positioned between two other layers.

As used throughout this application, the term “ethylene vinyl alcohol copolymer” or “EVOH” refers to copolymers sed of repeating units of ne and vinyl alcohol. Ethylene vinyl alcohol copolymers can be represented by the l formula: [(CHg-CH2)m-(CH2 -CH(OH))]n. Ethylene vinyl alcohol copolymers may include saponified or hydrolyzed ethylene vinyl acrylate copolymers. EVOH refers to a vinyl alcohol copolymer having an ethylene co-monomer and prepared by, for example, hydrolysis of vinyl acrylate copolymers or by chemical reactions with vinyl alcohol. The degree of hydrolysis is preferably at least 50% and, more preferably, at least 85%.

Preferably, ethylene vinyl alcohol copolymers comprise from about 28 mole percent to about 48 mole percent ethylene, more ably, from about 32 mole percent to about 44 mole percent ethylene, and, even more preferably, from about 38 mole percent to about 44 mole t ethylene.

As used throughout this application, the term "poiyamide" or “PA” or “nylon” refers to a homopolymer or mer having an amide linkage between monomer units which may be formed by any method known to those skilled in the art. The amide linkage can be represented by the general formula: [C(O)-R-C(O)-N H-R’~NH]n where R and R' are the same or different alkyl (or aryl) group. Examples of nylon potymers include but are not limited to nylon 6 aprolactam), nylon 11 (polyundecanoiactam), nylon 12 (polyauryllactam), nylon 4,2 (polytetramethylene ethylenediamide), nylon 4,6 (polytetramethylene adipamide), nylon 6,6 (polyhexamethylene adipamide), nylon 6,9 (polyhexamethylene azelamide), nylon 6,10 (polyhexamethylene mide), nylon 6,12 (polyhexamethylene dodecanediamide), nylon 7,7 (polyheptamethylene pimelamide), nylon 8,8 (polyoctamethylene suberamide), nylon 9,9 (polynonamethylene azelaiamide), nylon 10,9 (polydecamethyiene azelamide), and nylon 12,12 odecamethylene dodecanediamide). Examples of nylon copolymers include but are not limited to nylon 6,6/6 copolymer (polyhexamethylene adipamide/caprolactam copolymer), nylon 6,6/9 copolymer (polyhexamethylene adipamide/azelaiamide copolymer), nylon (3/66 mer aprolactam/hexarnethylene adipamide copolymer), nylon 6,2/6,2 copolymer examethylene ethylenediamide/hexamethylene ethylenediamide copolymer), and nylon 6,6/6,9/6 copolymer (polyhexamethylene adipamide/hexamethylene azelaiamide/caprolactam copolymer). Examples of ic nylon polymers include but are not limited to nylon 4,|, nylon 6,|, nylon 6,6/6l copolymer, nylon 6,6/6T copolymer, nlen MXD6 (poly-m— xylylene adipamide), poly-p-xylylene adipamide, nylon 61/6T copolymer, nylon 6T/6l copolymer, nylon MXDI, nylon 6/MXDT/l copolymer, nylon 6T (polyhexamethylene terephthalamide), nylon 12T (polydodecamethylene terephthaiamide), nylon 66T, and nylon 6-3—T (poiy(trimethyl hexamethylene terephthalamide).

As used throughout this application, the term “ionomer” refers to a partialty neutralized acid copolymer.

As used throughout this application, the term "polypropylene” or “PP” refers to a homopolymer or copolymer having at least one propylene monomer e within the repeating backbone of the polymer. The propylene linkage can be represented by the general formula: H(CH3)]n.

As used throughout this application, the term "palindromic film” refers to a multi- layer film, the layers of which are ntially symmetrical. Examples of palindromic films are film or sheet having the layer configurations A/B/A or A or A/B/C/B/A or A/B/C/D/E/D/C/F/C/D/E/D/C/B/A, etc. An example of a layer configuration of a non- palindromic film would be A/B/C/A.

As used throughout this application, the term “thermoformed” refers to polymer film or sheet permanently formed into a desired shape by the application of a differential of heat, by the pressure between the film or sheet and a mold, by the ation combination of heat and the ation of a differential pressure between the film or sheet and a mold, or by any thermoforming technique known to those skilled in the art As used hout this application, the term oplastic” refers to a polymer or polymer mixture that softens when exposed to heat and then returns to its original condition when cooled to room temperature. In general, thermoptastic materiats may include natural or synthetic polymers. Thermoplastic materials may further include any polymer that is cross-linked by either radiation or chemical reaction during manufacturing or post-manufacturing processes.

As used throughout this application, the term “polymer” refers to a material which is the product of a polymerization or copolymerization reaction of natural, synthetic or combined l and synthetic monomers and/or co-monomers and is inclusive of homopolymers, copolymers, terpolymers, etc. In general, the layers of the chlorine-free packaging sheet bed in the present application may comprise a single polymer, a mixture of a single polymer and non-polymeric material, a combination of two or more polymers blended er, or a mixture of a blend of two or more polymers and non- polymeric al. It will be noted that many polymers may be synthesized by the mutual on of complementary monomers. it will also be noted that some polymers are obtained by the chemical modification of other polymers such that the structure of the macromolecules that constitute the ing polymer can be thought of as having been formed by the homopolymerization of a etical monomer.

As used throughout this application, the term "polyvinylidene chloride” or “PVDC” refers to a polymer derived from vinylidene chloride. PVdC may be formed from the polymerization of vinylide chloride with various rs including but not limited to acrylic esters and unsaturated yl groups.

Referring now to the drawings, is a diagrammatic cross-sectional view of the general embodiment of the chlorine-free packaging sheet described in the present application. Generic packaging sheet 60 comprises three layers: first rigid component 61, c multilayer film 62 and second rigid component 63. (In each of the figures of the present application, the dimensions are not to scale and may be exaggerated for clarity.) First rigid component 61 and second rigid component 63 may comprise the same material or may se different materials (relative to each . First rigid component 61 and second rigid component 63 comprise styrenic r, aromatic polyester, aliphatic polyester, polypropylene homopolymer, or blends of such.

Examples of styrenic polymers include but are not limited to high impact polystyrene (HIPS), general purpose polystyrene (GPPS) and styrene block copolymer (SBC). HIPS is sometimes called rubber-modified yrene and is normally produced by copolymerization of styrene and a synthetic rubber. (See Wagner, et al., “Polystyrene,” The Wiley Encyclopedia of Packaging Technology, Second Edition, 1997, pp. 768-771 (John Wiley & Sons, lnc., New York, New York), which is incorporated in its entirety in this application by this reference.) Examples of HIPS include but are not limited to Impact Polystyrene 825E and Impact Polystyrene 945E, both of which are available from Total Petrochemicals USA, Inc; E86025 Rubber Modified High Impact Polystyrene, which is ble from Chevron ps Company (The Woodlands, Texas); and 6210 High Impact Polystyrene, which is available from Ineos Nova LLC (Channahon, is). GPPS is often called crystal polystyrene, as a nce to the clarity of the resin. Examples of GPPS include but are not limited to Crystal Polystyrene 5248 and Crystal Polystyrene 5258, both of which are ble from Total Petrochemicals USA, inc. Styrene block copolymers (880) include styrene butadiene copolymers (SB). The styrene-butadiene copolymers that are suitable for packaging applications are those resinous block copolymers that typically contain a greater proportion of e than butadiene and that are predominantly polymodal with respect to molecular weight distribution. (See Hartsock, ne-Butadiene Copolymers,” The Wiley Encyclopedia of Packaging Technology, Second Edition, 1997, pp. 863-864 (John Wiley & Sons, Inc., New York, New York), which is incorporated in its entirety in this application by this reference.) A non-limiting example of SB is DK13 K-Resin® Styrene- Butadiene Copolymer, which is available from Chevron ps Chemical Company (The Woodlands, Texas).

Examples of aromatic ters include but are not limited to polyethylene terephthalate (PET), oriented polyethylene thalate (OPET), amorphous polyethylene terephthalate (APET) and glycol-modified polyethylene terephthalate . A non-limiting example of APET is EastmanTM PET 9921, which is available from Eastman Chemical Company (Kingsport, Tennessee). A non-limiting e of PETG is EastarTM Copolyester 6762, which is also available from Eastman Chemical Company (Kingsport, Tennessee). An example of an aliphatic polyester includes but is not d to polylactic acid (PLA).

Examples of polypropylene homopolymer include but are not limited to those polypropylene homopolymers traditionally used to cast . Non-limiting examples of such polypropylenes include Polypropylene 3287WZ, which is available from Total Petrochemicals USA, Inc. on, Texas); and HOZC—OO Polypropylene Homopolymer, which is available from lneos Olefins & Polymers USA (League City, Texas).

More specifically, first rigid component 61 and second rigid component 63 may each comprise HIPS, APET, PETG, a blend of GPPS and SB, a blend of HIPS and GPPS, a blend of HIPS, GPPS and SB, a blend or APET and SB, or blends of such.

First rigid component 61 and second rigid component 63 may each also comprise processing aids and/or color concentrates. Examples of processing aids e but are not limited to slip/antiblock concentrates, such as SKR 17 available from Chevron Phillips Corporation (The Woodlands, Texas); release agents, such as SF18- 350 Polydimethylsiloxane Fluid available from DC Products Pty Ltd (Mt. Waverley, Victoria, Australia); and slip agents, such as axTM PS available from Croda Polymer ves (Cowick, United Kingdom). Examples of color concentrates include but are not limited to Accel A14477SGCP1 White Color Concentrate and Accel A19111S4CP1 Blue Color trate, both of which are available from Accel Corporation (Naperville, Illinois).

Returning to as described above, generic packaging sheet 60 also comprises generic multilayer film 62. shows the general embodiment of the packaging sheet 60 described in the present application. As such, generic multilayer film 62 may be a three-layer, four-layer, five-layer, layer, nine—layer, thirteen-layer or any other mUltilayer film (i.e., film having two or more layers), provided that the resulting generic packaging sheet 60 has a normalized ed tear initiation and propagation resistance in both the e direction and the erse direction of less than about 0.115 in*lbf / mil energy to break and less than about 0.800 % / mil elongation and has a normalized tear propagation resistance in both the machine ion and the transverse direction of less than about 0.300 in*lbf/ mil energy to break and less than about 0.145 lbf/ mil peak load (as further defined and described in the ES below). Embodiments of a chlorine-free packaging sheet comprising a five-layer film, a nine-layer film and a thirteen—layer film are shown in FIGS 2, 3 and 4, respectively. Generic multilayer film 62 may be a blown, coextruded film.

Referring to is a diagrammatic cross-sectional view of a first embodiment of the chlorine-free packaging sheet described in the present application.

First packaging sheet 70 comprises first rigid component 61, first ayer film 72 and second rigid component 63. First rigid component 61 and second rigid component 63 are as described above.

First multilayer film 72 comprises outer layer 74, first barrier component 78 and inner layer 76. In first ayer film 72 is shown as a yer romic film, resulting from a blown, coextruded three-layer tubular extrudate that is collapsed and flattened upon itself to form two inner tubular extrudate layers 50 (see and that is thermally laminated to itself at the two inner tubular extrudate layers 50 to form one inner layer 76.

Outer layer 74 may comprise ic copolymer, tie material, polyester anchor coat material, copolymer of ethylene and an ester, copolymer of ethylene and at least one alpha olefin, or polypropylene copolymer.

Outer layer 74 may comprise styrenic copolymer when first rigid component 61 and/or second rigid component 63 comprise styrenic copolymer. Styrenic copoiymers are as described above. As described above, a miting example of a styrenic copolymer is to DK13 K-Resin® Styrene-Butadiene Copolymers, which is ble from Chevron Phillips Chemical Company (The Woodlands, Texas).

.- Outer layer 74 may comprise tie material when first rigid component 61 and/or second rigid component 63 comprise tic polyester. Tie material includes but is not limited to glycidyl methacrylate—modified copolymers of ethylene (e.g., epoxy-functional tie materials), anhydride-modified (such as maleic anhydride modified) copolymers of ethylene, copolymers of ethylene and a carboxylic acid (such as an acrylic acid), copolymers of ethylene and an ester (such as an te), and blends of such. Further es of tie material are provided below.

Outer layer 74 may se polyester anchor coat material when first rigid ent 61 and/or second rigid component 63 comprise aromatic polyester.

Polyester anchor coat materials may be polyethylene-based and are known in the art.

Outer layer 74 may comprise copolymer of ethylene and an ester when first rigid component 61 and/or second rigid component 63 comprise polypropylene lymer. Examples of copolymers of ethylene and an ester include but are not limited to ethylene vinyl acetate copolymer (EVA). Non-limiting examples of EVA are described below.

Outer layer 74 may comprise copolymer of ethylene and at least one alpha olefin when first rigid component and/or second rigid component 63 comprise polypropylene homopolymer. Examples of copolymers of ethylene and at least one alpha olefin include but are not limited to linear low density polyethylene and piastomers. c non-limiting examples of such ethylene copolymers are DowlexTM 2045 Polyethylene Resin available from The Dow Chemical Company nd, Michigan) and ExactlM Plastomers (various grades) available from ExxonMobil al Company (Houston, Texas). Copolymers of ethylene and at least one alpha olefin are further described below.

Outer layer 74 may comprise polypropylene copolymer when first rigid ent 61 and/or second rigid ent 63 comprise polypropylene homopolymer. Polypropylene copolymers include but are not limited to impact copolymers, such as Propylene 4170 ble from Total Petrochemicals USA, Inc.

(Houston, Texas).

Outer layer 74 may also comprise processing aids. es of processing aids include but are not limited to slip/antiblock concentrates, such as SKR 17 available from Chevron ps ation (The Woodlands, Texas); and thermal stabilizers, such as SKR 20 available from Chevron Phillips Corporation (The nds, Texas).

For a palindromic film, inner layer 76 may comprise any material that is e of thermally laminating or heat sealing to itself. Examples of materials for inner layer 76 include but are not limited to high density polyethylene, low density polyethylene, copolymers of ethylene and at least one alpha-olefin, copolymers of ethylene and an ester, anhydride-modified copolymers of ethylene, copolymers of ethylene and a carboxylic acid, ionomers, styrenic copolymers, pressure sensitive adhesives, polypropylene copolymers or blends of such.

Examples of high density polyethylene (HDPE) include but are not limited to HDPE as described below.

Examples of copolymers of ethylene and at least one alpha-olefin include but are not d to butene LLDPE, such as ExxonMobilTM LLDPE LL1001.32 available from ExxonMobil Chemical Company (Houston, Texas); Dow LLDPE DFDA—7047 NT 7 available from the Dow Chemical Company (Midland, Michigan); Novapol® PF—O118—F available from Nova Chemicals Corporation (Calgary, Alberta, Canada); Sabic® LLDPE 118N available from Sabic Europe (Sittard, The Netherlands); and ExactTM Plastomers ble from ExxonMobil al Corporation (Houston, Texas).

Examples of copolymers of ethylene and an ester include but are not limited to ethylene vinyl acetate copolymer (EVA), ethylene methyl methacrylate copolymer, ethylene ethyl methacrylate copolymer and ethylene alkyi acrylates such as ethylene methyl acrylate, ethylene ethyl te and ethylene butyl acrylate. Non-limiting examples of EVA include EscoreneTM Ultra LD 705.MJ available from ExxonMobil Chemical Company (Houston, , EscoreneT'V' Ultra LD 768.MJ available from ExxonMobil Chemical Company (Houston, Texas) and Ateva® 2861AU available from se Corporation (Edmonton, a, Canada). es of anhydride-modified copolymers of ethylene include are but not limited to tie materials as described above and below.

Examples of mers of ethylene and a carboxylic acid include but are not limited to ethylene-methacrylic acid (EMAA) and ethylene acrylic acid (EAA).

A non-limiting example of ionomers (i.e., partially neutralized acid copolymers) is Surlyn® ble from E. l. du Pont de Nemours and Company (Wilmington, Delaware).

Examples of styrenic copolymers are as described above.

Examples of pressure sensitive adhesives (PSA) include but are not limited to those compositions that comprise a base meric resin and a tackifier to enhance the ability of the ve to instantly bond and to enhance the bond strength. es of eiastomers used as the base resin in tackified multicomponent PSA include but are not limited to natural rubber, polybutadiene, polyorganosiioxanes, styrene-butadiene rubber, carboyxlated e-butadiene , poiyisobutylene, butyl rubber, halogenated butyl rubber, block polymers based on styrene with isoprene, butadiene, ethylene-propylene or ethylene-butylene, or combinations of such elastomers. (See Yorkgitis, “Adhesive Compounds," Encyclopedia of Polymer Science and logy, Third Edition, 2003, Volume 1, pp. 256-290 (John Wiley & Sons, inc, Hoboken, New Jersey), which is incorporated in its entirety in this application by this reference.) A non-limiting specific example of a PSA is an ve comprising a block '10 copolymer of styrene and elastomer having a density of 0.96 g/cm3 and available as M3156 from Bostik Findley, Inc. (Wauwatosa, Wisconsin).

Examples of polypropylene copolymers include but are not limited to propylene, ethyiene and/or butene copolymers. A miting specific e of such copolymers is VersifyT'V' Plastomers and Elastomers us grades) available from The '15 Dow Chemical Company nd, Michigan).

Inner layer 76 may comprise a blend of any of the above materials. As a non- iimiting example, this blend may be a blend of copolymers of ethylene and an ester and copolymers of ethylene and at least one alpha olefin. As a further non-limiting example, this blend may be a blend of EVA and LLDPE. As an even further non—limiting example, this blend may be a biend of EscoreneTM Ultra LD 768.MJ and ExxonMobilTM LLDPE LL1001.32. inner layer 76 may also comprise processing aids. es of processing aids include but are not limited to antiblock additives, such as t® 10853 ble from Ampacet Corporation (Tarrytown, New York).

Returning to as described above, first multilayer film 72 of first packaging sheet 70 also comprises first barrier component 78. In this embodiment, first barrier component 78 comprises a single layer, which may be a barrier layer comprising high y hylene (HDPE), low density polyethylene (LDPE), copolymer of ethylene and at least one alpha olefin, or blends of such.

LDPE and copblymer of ethylene and at least one alpha olefin is each described above; HDPE-is also described above. HDPE may be further described as a semicrystalline polymer. It may be a lymer when the density is 3 0.960 g/cm3 and a copolymer when the density is below this value. HDPE is available in a wide range of molecular weights as determined by either melt index (Ml) or HLMl load melt . (See Carter, “Polyethylene, High-Density," The Wiley opedia of Packaging Technology, Second Edition, 1997, pp. 745-748 (John Wiley & Sons, inc, New York, New York), which is incorporated in its entirety in this application by this reference.) Specific non—limiting examples of HDPE include Alathon® M6020 available from Equistar als LP (Houston, Texas); Alathon® L5885 available from Equistar Chemicals LP (Houston, Texas); ExxonMobilTM HDPE HD 7925.30 available from ExxonMobil Chemical Company (Houston, Texas); Exxonil/lobilTM HDPE HD 7845.30 available from ExxonMobil Chemical Company (Houston, Texas); and Surpass® HPs167—AB available from Nova Chemicals Corporation (Calgary, Alberta, Canada First barrier component 78 may also comprise tie material. As described above, tie material includes but is not limited to glycidyl methacrylate—modified copolymers of ethylene (e.g., epoxy-functional tie materials), anhydride-modified (such as maleic anhydride modified) copolymers of ethylene, copolymers of ethylene and a carboxylic acid (such as an acrylic acid), copolymers of ethylene and an ester (such as an acrylate), and blends of such. Specific non-limiting examples of tie material inciude Lotader® AX 8900 available from Arkema Inc. (Philadelphia, Pennsylvania); GT4157 availabte from Westlake Chemical Corporation (Houston, Texas); DuPontTM Bynel® 41 E710 available from El du Pont de s and Company, Inc. (Wilmington, re); T'V' Bynel® 41 E687 available from El du Pont de Nemours and Company, Inc. (Wilmington, Delaware); Plexar® PX 3084 available from Equistar Chemicals LP (Houston, Texas); M A available from Mitsui als America, Inc. (Rye Brook, New York); DuPontTM Bynel® 40E529 available from El. du Pont de Nemours and Company, lnc. (Wilmington, Delaware); DuPontTM Bynel® 4164 available from El du Pont de Nemours and Company, Inc. (Wilmington, Delaware); Plexar® PX 3080 available from ar Chemicals LP on, Texas); and r® 2210 available from Arkema Inc. (Philadelphia, Pennsylvania).

First barrier component 78 may also comprise a nucleating agent, a hydrocarbon resin or blends of such.

In embodiments of the present ation in which the barrier component comprises HDPE blended with nucleating agent, the HDPE may have a medium molecular weight, a melt index within the range of about 0.5 to about 50 dg/min, a density greater than or equal to about 0.941 g/cm3, a iong chain branching index or less _30- than or equal to about 0.5 and a melt flow ratio less than or equal to about 65. (See US Patent Apptication 2007/0036960, published February 15, 2007, which is incorporated in its entirety in this application by this nce.) A nucleating agent may comprise any of those nucleating agents disclosed in US Patent 556, issued November 29, 2005, which is incorporated in its ty in this application by this reference. More specifically, as a non-limiting example, the nucleating agent may comprise glycerol alkoxide Salts, hexahydrophthalic acid salts, similar salts or mixtures of such salts, as disclosed in US Patent Application 2008/0227900, hed September 18, 2008, and in US Patent Application 2007/0036960, published February 15, 2007, both are which are incorporated in their entireties in this application by this reference. Such salts include ammonium and metal salts, including but not limited to zinc, magnesium, calcium and mixtures of such metals.

An example of a zinc olate nucleating agent is lrgastab® 287 available from Ciba Specialty Chemicals Holding. inc. (Basel, Switzerland). An example of a calcium hexahydrophthalate is Hyperform® HPN-ZOE available from Millikan & Company (Spartanburg, South na). Calcium hexahydrophthalate is also available d with LDPE as Polybatch® CLR122 available from A. Schulman Inc. , Ohio). The nucleating agent may be included in barrier component layer (or layers) in an amount from about 0.001% to about 1% by weight (of the layer), from about 0.002% to about 0.2% by weight, from about 0.02% to about 0.12% by weight, or from about 0.04% to about 0.10%.

A arbon resin may comprise any of those hydrocarbon resins disclosed in US Patent 6,432,496, issued August 13, 2002, or in US Patent Application 2008/0286547, published November 20, 2008, both of which are incorporated in their entireties in this ation by this nce. More specifically, as a non-limiting e, the hydrocarbon resin may include petroleum resins, terpene resins, styrene resins, cyclopentadiene , saturated alicyclic resins or mixtures of such resins.

Additionaily, as a non-limiting e, the hydrocarbon resin may comprise hydrocarbon resin derived from the polymerization of olefin feeds rich in dicyclopentadiene (DCPD), from the polymerization of olefin feeds produced in the petroleum cracking process (such as crude Cg feed streams), from the polymerization of pure monomers (such as styrene, d-methylstyrene, 4-methylstyrene, vinyltoluene or combination of these or similar pure monomer feedstocks), from the polymerization terpene olefins (such as d-pinene, B—pinene or d-limonene) or from a combination of such. The hydrocarbon resin may be fully or partially hydrogenated. Specific examples of hydrocarbon resins include but are not limited to Plastolyn® R1140 arbon Resin available from n Chemical Company (Kingsport, Tennessee), Regalite® T1140 available from Eastman Chemical y (Kingsport, Tennessee), Arkon® P- 140 available from Arakawa Chemical industries, Limited (Osaka, Japan) and Piccoiyte® S135 Polyterpene Resins available from Hercules Incorporated (Wilmington, Delaware). The hydrocarbon resin may be included in barrier component layer (or layers) in an amount from about 5% to about 30% by weight (of the layer), from about 5 to about 20 % by weight, from about 10% to about 20% by weight, or from about 10% to about 15% by weight. is a diagrammatic sectiona| view of a second embodiment of the chlorine-free packaging sheet bed in the present ation. Second packaging sheet 80 comprises first rigid component 61, second multilayer fiim 82 and second rigid component 63. First rigid component 61 and second rigid component 63 are as described above.

Second multilayer film 82 ses outer layer 74, second barrier component 88 and inner layer 76. in second multilayer film 82 is shown as a seven-layer palindromic film, resulting from a blown, coextruded four-layer r extrudate that is collapsed and flattened upon itself to form two inner tubular extrudate layers 50 (see and that is thermally laminated to itself at the two inner tubular extrudate layers 50 to form one inner layer 76. Outer layer 74 and inner layer 76 are as described above.

Second barrier component 88 comprises two layers: first barrier layer 83 and second r layer 84. First barrier layer 83 and second barrier layer 84 may each comprise HDPE, LDPE, copolymer of ethylene and at least one alpha olefin, or blends of such; each of these materials is as described above. First barrier layer 83 may also comprise tie material; this tie material is as described above. Furthermore, first barrier iayer 83 may also comprise nucleating agent, arbon resin or blends of such; each of these materials is as described above. is a diagrammatic cross-sectional view of a third embodiment of the chlorine-free packaging sheet described in the present application. Third packaging sheet 90 ses first rigid component 61, third multilayer film 92 and second rigid component 63. First rigid component 61 and second rigid ent 63 are as described above.

Third ayer film 92 comprises outer layer 74, third barrier component 98 and inner layer 76. in FlG. 4, third multilayer film 92 is shown as a thirteen-layer palindromic film, resulting from a blown, coextruded seven-layer tubular extrudate that is sed and flattened upon itself to form two inner tubular extrudate layers 50 (see FtG. 6) and that is thermally laminated to itself at the two inner tubular extrudate layers 50 to form one inner layer 76. Outer layer 74 and inner layer 76 are as described above.

Third barrier component 98 comprises five layers: first barrier ent layer 93, first intermediate iayer 94, oxygen barrier layer 95, second intermediate iayer 96 and moisture barrier layer 97.

In one ment of third packaging sheet 90, first r component layer 93 and at least one alpha olefin, or may comprise HDPE, LDPE, copolymer of ethylene blends of such; each of these als is as described above. First barrier component layer 93 may also comprise tie material; this tie material is as described above. rmore, first barrier component layer 93 may also comprise nucleating agent, hydrocarbon resin or blends of such; each of these materials is as described above. As such, in one embodiment of third packaging sheet 90, first r component layer 93 and nucleating agent. may comprise a blend of HDPE, tie material In another embodiment of third packaging sheet 90, first barrier component layer 93 may comprise a copolymer of ethylene and an ester. Copolymers of ethylene and of a an ester are as described above. As described above, a non-limiting example copolymer of ethylene and an ester is EVA. As described above, one non-limiting example of EVA is EscoreneT'V' Ultra LD 705.MJ available from Exxoanlobii Chemical Company (Houston, Texas).

First ediate layer 94 may se tie material or polyamide, Tie material is as described above. Polyamide (which is further described above) may be ed .for clarity, thermoformability, high strength and toughness over a broad ature range, chemical ance and/or barrier properties. (See “Nylon,” The Wiley Encyclopedia of ing Technology, Second Edition, 1997, pp. 681-686 (John Wiley & Sons, Inc., New York, New York), which is incorporated in its ty in this application by this reference.) Specific, miting examples of polyamide include UBE Nylon 5033 8 available from UBE Engineering Plastics, S.A. (Castellén, Spain); Ultramid® C40 L 01 available from BASF Corporation (Florham Park, New Jersey); Ultramid® C33 01 available from BASF Corporation (Florham Park, New Jersey); and a blend of 85% by weight (of the blend) of Ultramid® BB6 available from BASF Corporation (Florham Park, New Jersey) and 15% by weight ofDuPontTM Selar® PA3426 ble from El. du Pont de Nemours and Company, Inc. (Wilmington, Delaware).

Oxygen barrier layer 95 may comprise any chlorine-free oxygen barrier al. ln the embodiment of third packaging sheet 90 comprising third multilayer film 98, the barrier material is split (i.e., in non-adjacent layers) as a result of the seven-layer tubular extrudate being collapsed and flattened upon itself to form two inner tubular extrudate layers and thermally laminated to itself at the two inner tubular extrudate layers.

Examples of chlorine—free barrier materials include but are not limited to EVOH, polyamide, polyglycolic acid and acrylonitrile-methyl acrylate copolymer.

EVOH is as described above. Specific non—limiting examples of EVOH include EVALTM H171 available from EVAL Company of America (Houston, Texas); Evasin EV- 3801V available from Chang Chun Petrochemical Co., Ltd. (Taipei, Taiwan); and Soarnol® ET3803 available from Soarus L.L.C. (Arlington Heights, Illinois).

Polyamide is as described above. Specific non-limiting examples of polyamide include Nylon MX06® (various grades) available from Mitsubishi Gas Chemical Company, inc. (Tokyo, Japan); and a blend of 85% by weight (of the blend) of Ultramid® B36 available from BASF ation (Florham Park, New Jersey) and 15% by weight of DuPontTM Selar® PA3426 available from El. du Pont de Nemours and Company, Inc. (Wilmington, Delaware). ycolic acid (PGA) (or polyglycolide) is a biodegradable, thermoplastic polymer and the simplest linear, aliphatic polyester. It offers high gas barrier to carbon dioxide and , llable hydrolysis and excellent ical strength.

AcrylonitriIe—methyl acrylate copolymer imparts high barrier to gases (such as oxygen), aromas and fragrances as well as chemical resistance and inertness. A specific non-limiting example of acrylonitrile~methyl acrylate mer is Barex® (various grades) available from Ineos Olefins & Polymers USA e City, Texas).

Second intermediate layer 96 may comprise tie material or polyamide. Tie material and polyamide are each as described above.

Moisture r layer 97 may comprise HDPE, LDPE, copolymer of ethylene and at least one alpha olefin, or blends of such; each of these materials is as described above. Moisture barrier layer 97 may also comprise tie material; this tie material is as described above. Furthermore, moisture barrier layer 97 may also comprise ting agent, hydrocarbon resin or biends of such; each of these materials is as described above. As such, in one embodiment of third packaging sheet 90, moisture barrier layer 97 may se a blend of HDPE and nucleating agent. In another embodiment of third packaging sheet 90, moisture barrier layer 97 may se a blend of HDPE, tie material and nucleating agent. in an alternate ment, a non-oriented film comprises at least one moisture barrier layer comprising a blend. The blend comprises high y polyethylene, hydrocarbon resin and nucleating agent.

The blend comprises from about 69 °/o by weight to about 90 % by weight high density polyethylene or from about 72 % by weight to about 88 % by weight high density polyethylene or from about 75 % by weight to about 85 % by weight high density polyethylene. it is important that the high density polyethylene has a melt index of at least 1.0 g/10 min and a density greater than 0.958 g/cc. High density polyethylenes which do not y these requirements afford poor results. An example of a high density polyethylene which has a melt index of at least 1.0 g/10 min and a density greater than 0.958 g/cc is Alathon® M6020 (Equistar Chemicals, LP, Houston, Texas).

Other high density polyethylenes such as Alathon® L5485 (Lyondell Chemical Company, Houston, Texas), ExxonMobilTM HDPE HD 7845.30 (ExxonMobil Chemical Company, Houston, Texas) and n® L5885 (Lyondell Chemical Company, Houston, Texas) do not have the required density and/or melt index and are not preferred for the blend of the moisture barrier layer of the non-oriented film of the t application.

The blend further comprises a hydrocarbon resin as described above. The blend comprises from about 5 % by weight to about 30 % by weight hydrocarbon resin or from about 5 % by weight to about 20 % by weight hydrocarbon resin or from about 10 % by weight to about 20 % by weight hydrocarbon resin or from about 10 % by weight to about 15 % by weight hydrocarbon resin.

The blend of the non-oriented film further comprises a nucleating agent as described above. The blend comprises from about 0.01 % by weight to about 1 % by weight nucleating agent or from about 0.04 % by weight to about 0.10 % by weight nucleating agent. The nucleating agent may be a glycerol alkoxide salt, a hexahydrophthalic acid salt, zinc glycerolate salts or calcium hexahydrophthalate.

The non-oriented film may, in some aspects, se an oxygen barrier material as described above. When the non-oriented fiim comprises an oxygen barrier material, the film has a normalized oxygen transmission rate of less than about 150 /100 y or less than about 100 cc—mil/100 in2/day.

The non-oriented film may have a thickness of less than 3.00 mil, preferably less than 1.70 mil.

Referring to non~oriented film 100 may be a three-layer film comprising a re barrier layer but not necessarily the first rigid component nor the second rigid component as described above. The moisture barrier layer comprises a blend comprising a high density polyethylene, n the high y polyethylene has a melt index of at least 1.0 g/10 min and a density greater than 0.958 g/cm3, a hydrocarbon resin and a nucleating agent.

With reference to a generic non-oriented film may comprise the moisture barrier layer in any of the three layers 101, 102 or 103 of the multilayer film. For example, the moisture barrier layer may be middle layer 102 or, alternatively, outer layer 101 or inner layer 103. The non-oriented film may be a three-layer, four-layer, five- layer, layer, nine~layer, thirteen-layer or any other ayer film (i.e., film having two or more layers), provided that the non-oriented film has a normalized moisture vapor transmission rate of no greater than 0.30 g-mil/100 in2/day measured at about 100 °F and 90 % external relative humidity (as further defined and described in the EXAMPLES below). Embodiments of a non-oriented film comprising afive—layer film, a nine-layer film and a thirteen-layer film are shown in FIGS. 8, 9 and 10, respectively.

The non-oriented film may be a blown, coextruded film.

The non-oriented film may comprise layers other than the re barrier layer.

For example, the film may se at least one layer comprising an ionomer, at least one layer comprising a high density polyethylene, at least one layer comprising a copolymer of ethylene and an ester, at least one layer comprising an ethylene vinyl acetate copolymer (EVA), at least one layer comprising a styrene butadiene copolymer, or combinations of the above. In some aspects, the film comprises a layer comprising high density polyethylene in addition to the moisture barrier layer. In other aspects, the film comprises the moisture barrier layer and a t layer coated with PET. is a diagrammatic cross-sectional View of a second alternate embodiment of non-oriented film 110, as described in the present application. Any of the five layers 111, 112, 113, 114, and 115 may comprise the moisture barrier layer comprising a HDPE, a hydrocarbon resin and nucleating agent. in some aspects, more than one layer may comprise the moisture barrier layer. For example, layers 115 and 113 may comprise the barrier layer. One e of a five-layer film is layer 115 as a 0.8 mil thick layer with a blend of HPDE, nucleating agent and arbon resin, layer 114 as a 0.8 mil thick layer with a blend of LLDPE, LDPE and nucleating agent, layer 113 as a 0.2 mil thick layer with a blend of HDPE, nucleating agent and arbon resin, layer 112 as a 0.1 mil thick layer with a blend of EVA and polybutylene and layer 111 as a 0.1 mil thick layer with EVA. is a diagrammatic cross-sectional view of a third alternate embodiment of the non-oriented film described in the present application. The multilayer film 120 is shown as a nine-layer palindromic film, resulting from a blown, coextruded five—layer tubular extrudate that is collapsed and flattened upon itself to form two inner tubular extrudate layers 50 (see and that is thermally laminated to itself at the two inner tubular extrudate layers 50 to form one inner layer 125.

FIG 10 is a mmatic cross~sectional view of a fourth alternate embodiment of the iented film bed in the present application. The multilayer film 130 is shown as a thirteen—layer palindromic film, resulting from a blown, coextruded seven- layer tubular extrudate that is collapsed and flattened upon itself to form two inner tubular extrudate layers 50 (see and that is thermally laminated to itself at the two inner tubular extrudate layers 50 to form one inner layer 137. The multilayer film comprises at least one moisture barrier layer and may ally comprise more than one moisture barrier layer. As described above, the moisture barrier layer comprises HDPE, hydrocarbon resin and nucleating agent. In some aspects, moisture barrier layers comprising a HDPE, a hydrocarbon resin and a nucleating agent may be used for layers 132, 134, and 136. In other aspects, a moisture barrier layer comprising a HDPE, a hydrocarbon resin and a nucleating agent may be used for layer 136.

Generic ing sheet 60, as embodied in first ing sheet 70, second packaging sheet 80, third packaging sheet 90 or ise, and the non-oriented film, as embodied in film 100, 110, 120, 130 or otherwise, may be included in a package for a product. In one embodiment, the package comprising the chlorine-free ing sheet or non-oriented film described in this application may be a thermoformed package ing from the packaging sheet or iented film having been thermoformed.

A description of “thermoformed” is provided above. rmore, thermoforming and other similar techniques are well known in the art for packaging. (See Throne, “Thermoforming,” Encyclopedia of Polymer e and Technology, Third Edition, 2003, Volume 8, pp. 222-251 (John Wiley & Sons, Inc., Hoboken, New Jersey), which is incorporated in its entirety in this ation by this reference; see also InNin, “Thermoforming,” Modern Plastics Encyclopedia, 19844985, pp. 329-336 (McGraw—Hill, inc., New York, New York), which is incorporated in its entirety in this application by this reference; see also “Thermoforming,” The Wiley Encyclopedia of Packaging Technology, Second Edition, 1997, pp. 1 (John Wiley & Sons, Inc., New York, New York), which is incorporated in its entirety in this application by this reference.) Suitable thermoforming methods include standard, deep-draw or plug-assist vacuum forming. During rd vacuum forming, a thermoplastic web, such as a film or sheet, is heated and a vacuum is applied beneath the web allowing atmospheric pressure to force the web into a preformed mold. When relatively deep molds are employed, the process is referred to as a "deep-draw" ation. In a plug—assist vacuum forming method, after the thermoplastic web has been heated and sealed across a mold cavity, a plug shape similar to the mold shape impinges on the thermoplastic web and, upon the appiication of vacuum, the thermoplastic web conforms to the mold surface.

The thermoformed package comprising the chlorine-free packaging sheet or non- oriented film described in the present ation may be a cup, a tub, a bucket, a tray or a myriad of other items. Furthermore, the product contained in the thermoformed e may be a food, od, medical and/or industrial product. Examples of such products include but are not limited to syrups ding but not limited to breakfast syrup, cough syrup, etc), creams, cheeses, condiments (including but not limited to salad dressings, jellies, jams, ketchup, etc.), personal care items (including but not limited to shampoos, hand creams, ashes, toothpastes, antacids, etc), medications, liquid detergents, oils, pates, pet foods, glues, ges (including alcoholic and non-alcoholic) and confections (including but not d to hard , fudge, toffee, licorice, chocolate, jelly candies, marshmallow, marzipan, divinity, pastry, chewing gum, ice cream, etc).

Generic ing sheet 60, as embodied in first packaging sheet 70, second packaging sheet 80, third packaging sheet 90 or othen/vise, and iented film, as embodied in films 100, 110, 120, 130 or otherwise, may manufactured by various methods. In general, the methods comprise the sequential steps of (a) adding thermoplastic resins to extruders to extrude the various layers of the sheet or film, such as, for example, an outer layer of an n—layer multilayer barrier film, an intermediate layer (which may be but not necessarily is a barrier component of the multilayer barrier film) and an inner layer of the multilayer barrier film, such that the intermediate layer is positioned between the outer layer and the inner layer of the multilayer barrier film and such that the multilayer barrier film has a first surface and an opposing second surface; (b) heating the thermoplastic resins to form streams of melt-plastifiecl polymers; (0) forcing the streams of melt-plastified polymers h a die having a central orifice to form a tubular ate having a diameter and a hollow interior; (d) expanding the diameter of the tubular extrudate by a volume of fluid (such as a volume of gas) entering the hollow interior via the central orifice; (e) collapsing the tubular ate; (f) flattening the tubular extrudate to form two inner tubular extrudate layers. In embodiments of the generic packaging sheet 60, the method further comprises the steps of (g) attaching a first rigid component to the first surface of the multilayer barrier film; and (h) attaching a second rigid component to the opposing second surface of the multilayer barrier film. It is to be understood that steps (g) and (h) are not ed for the non—oriented film.

Referring again to the drawings, is a schematic representation of a blown film process for producing a multilayer film included in the chlorine-free ing sheet or non-oriented film described in the present application. ageousiy, this multilayer blown film may be extruded, blown, cooled, collapsed, etc, using well known and available equipment. depicts a schematic view of a typical s 10 for steps (a) — (f) above.

' In the depicted process 10, first thermoplastic resin 11 for an outer layer of a multilayer barrier film is placed in first hopper 12 of first extruder 13. The er 13 is heated to an appropriate temperature above the melting point of the first thermoplastic resin 11 such that first thermoplastic resin 11 is heated to form streams of melt-plastified polymers. Extruder 13 may also be provided with a jacketed chamber through which a cooiing medium is circulating. The rotation of a screw within first extruder 13 forces melt—plastified polymer h first connecting pipe 14 through coextrusion die 15.

Simultaneous with the introduction of the melt-plastified first thermoplastic resin 11 to coextrusion die 15, second thermoplastic resin 16 (which has been placed in second hopper 17 of second extruder 18) is similarly heated to form streams of melt- plastified rs and forced by second extruder 18 through second connecting pipe 19 through coextrusion die 15. Third thermoplastic resin 20 is similarly heated to form streams of melt-plastified polymers and forced by third extruder 22 through third connecting pipe 23 through usion die 15. In the embodiment of first packaging sheet 70, three extruders are typically used to produce first multilayer film 72. In other ments, additional extruders may be used. For example, four extruders are typically used to produce second multilayer film 82; five extruders are typically used to produce multilayer film 120 and seven extruders are typically used to produce third multilayer film 92 or multilayer film 130. However, in the coextrusion art it is also known that when the same thermoplastic resin is used in more than one layer of a multilayer film, the melt-plastified resin from one extruder may be divided at the die and used for multiple . In this way, a five-layer film may be made using three or four extruders.

The usion die 15 has an annular, preferably circular, opening and is designed to bring together the first, second and third melt—plastified thermoplastic resins such that the first, second and third melt-plastified thermoplastic resins are coextruded out of the coextrusion die 15 as tubular extrudate 24. In the art, the term “tubular ate" is synonymous with the terms “bubble” and “blown .” Coextrusion die is equipped, as is known in the art, with a central orifice h which a fluid, such as a volume of gas, is typically introduced to radially expand the er of tubular extrudate 24 forming an expanded tubular extrudate 24 having an exterior surface 25 and interior surface 26. in a multilayer film, such as first multilayer film 72, outer layer 74 of first multilayer film 72 ponds to the outermost layer of tubular extrudate 24 and inner layer 76 of first ayer film 72 corresponds to the innermost layer of tubular extrudate 24.

Tubular extrudate 24 may be externally cooled by cooling means such as air ring 27 which blows cooling air along lower outer surface 28 of tubular extrudate 24.

Simultaneously, internal surface 26 may be , such as by contact with refrigerated air (at a temperature of, for example 5 °C — 15 °C) delivered through an internal bubble cooling unit having perforated pipe 29. Perforated pipe 29 is concentrically disposed around longer pipe 30 of narrower diameter. Longer pipe 30 is open at distal end 31 to e and remove warmer air which has risen to upper end 32 of tubular extrudate 24.

The s of external and internal cooling fluids, such as air and/or water, constitute a cooling zone serving to chill or set r ate 24 at the desired diameter.

Tubular extrudate 24 may be stabilized by external concentric cage 33 to help maintain tubular extrudate 24 along a straight path to a collapsing frame or ladder comprising a series of converging rolls 34. Concentric cage 33 may be particularly useful to stabilize films made using an internal bubble cooling unit.

Tubular extrudate 24 is collapsed in converging rolls 34 and flattened by driven nip rolls 35, which may also assist in collapsing tubular extrude 24. Driven nip rolls 35 function to pull and/or transport tubular extrudate 24 and also to collapse tubuiar extrudate 24 to form flattened extrudate 26. However, other ort means and collapsing means may be employed and are known in the art; these means e but are not limited to such apparatus as collapsing ladders and drive belts.

Referring now to a cross-sectional view of tubular extrudate 24, made according to the process of is shown having or surface 25 and interior surface 26. r extrudate 24 has three layers: inner tubular extrudate layer 50, intermediate tubular extrudate layer 51 (which may be but not necessarily is a barrier component extrudate layer) and outer tubular extrudate layer 52. Each extrudate layer may comprise any number of layers. For example, as a barrier component extrudate of layers, layer, intermediate tubular extrudate layer 51 may se any number including but not limited to one layer as in first barrier component 78 (see FlG. 2), two third barrier layers as in second barrier component 88 (see and five layers as in component 98 (see .

As tubular extrudate 24 is collapsed and flattened by converging rolls 34 driven nip rolls 35 to form flattened extrudate 36, two inner tubular extrudate layers laminate to are formed. The two inner tubular extrudate layers 50 may thermally themselves to form one inner layer, resulting in a palindromic multilayer film having a first surface and a second surface. This is ed if the blown film equipment is operated at a high enough output rate (as ined by a person of ordinary skill in art without undue experimentation) so that the flattened extrudate 36 is of sufficient ature for such thermal lamination. If flattened extrudate 36 is laminated to itself, the resulting palindromic, ayer film is conveyed by rollers (not shown in to a wind-up reel (not shown in FlG. 5) for r sing.

Alternatively, flattened extrudate 36 may be slit open into one or more sheets which may be wound on paperboard or plastic cores for subsequent dispensing or use. slitter in the embodiment depicted in FlG. 5, flattened extrudate 36 is ed through 37 where the flattened extrudate is slit by knives to form a first multilayer film 38 and a second multilayer film 39. First ayer film 38 is conveyed by first rollers 40 to first wind-up reel 41 for further processing, and second multilayer film 39 is conveyed by second rollers 42 to second wind—up reel 43 for further processing.

In producing a multilayer film included in the chlorine-free packaging sheet or non—oriented film described in the present application, it will be appreciated by those skilled in the art that such parameters as the usion die diameter, nip roll speed, amount and temperature of fluid (e.g., air) uced and captured between the coextrusion die and nip rolls, flow rate of the tubular extrudate from the coextrusion die, melt temperatures, type of cooling medium (e.g. water or air), and internal and external tubular ate cooling temperatures may all be adjusted to optimize process conditions. For example, the circumference or lay-flat width of the r ate die diameter by may be increased to varying degrees above that of the usion modification of one or more of the above parameters. Similarly, the tubular extrudate and may be conditioned or d, such as by internal and/or external application ion of the types, amounts and characteristics of als (including gaseous or liquid fluids contacting the tubular extrudate) as well as by setting and changing such parameters as pressures and atures. It will be understood in the art that such parameters may vary and will depend upon practical considerations, such as the particular thermoplastic resins comprising the tubular extrudate, the presence or absence of modifying agents, the equipment used, desired rates of production, desired tubular extrudate size (including diameter and thickness), and the quality and desired performance characteristics of the tubular extrudate. These and other process parameters are expected to be set by one skilled in the art without undue experimentation. Also, n non-uniformities in processing, including but not d to variation in film thickness, unequal heating or cooling of the tubular extrudate and iform air flows, may be obviated by rotation with or without oscillation, either alone or in combination, of the usion die, the air ring or other apparatus with respect to the vertical axis of the tubular extrudate. It should also be understood that while manufacture of the tubular extrudate has been described above with respect to a coextrusion process which used vertical upward transport of the tubular extrudate and expanded tubular extrudate, those skilled in the art may extrude and expand the tubular extrudate in other directions ing vertically downward.

After the multilayer film included in the chlorine-free packaging sheet is produced, a first rigid ent is attached to a first surface of the film. A second rigid component is then attached to the opposing second e. The first rigid component and the second rigid component may be attached by various methods as known in the art. These methods include but are not limited to thermal tion, adhesive lamination (including solvent or solvent-less lamination), extrusion iamination and extrusion coating. As described above, the parameters for such lamination or coating are expected to be set by one skiiled in the art without undue experimentation.

Examples 1—8 are chiorine-free packaging sheets exemplifying the present invention. Each of these packaging sheets is produced, generally, as foliows: A multilayer, blown, coextruded film is produced and thermally ted to itself at the inner layers, then a first rigid ent is extrusion coated on a first surface of‘the blown film and then a second rigid component is extrusion coated on the ng second surface of the blown film.

Comparative Examples are also produced and/or were ed. ative Examples 1, 5 and 6 are ed, generally, as follows: A multilayer, blown, coextruded film is produced and then a first rigid component is extrusion coated on a first surface of the blown film. Comparative Examples 2, 3 and 4 were obtained and are further described below.

More specifically, in producing the blown films of Examples 1-8 and Comparative Examples 1, 5 and 6, various materials are first added to the extruders of a blown film line to produce a seven—layer blown, coextruded film. The seven-layer blown, coextruded films of Examples 1-8 have the compositions (by approximate weight percent) shown in TABLE 1 and TABLE 2; and the seven—layer blown, coextruded films on Comparative Examples 1, 5 and 6 have the compositions (by approximate weight percent) shown in TABLE 3.

TABLE 1 ; Exam les 2-5 Weight % Component Weight % Weight % Component Weight % of Film of Layer of Film of Layer First 1390— 98.50 9‘50 (or ") processing aid 1.50 corocessin aid 12.60 EVA 1 100.00 24.00 HDPE 78.0 (or "First Barrier Tie Resin 2 20.0 Component") LDPE/Nucleating No000 Agent Blend Third 7.60 Tie Resin 1 100.00 7.60 Tie Resin 2 —L o .0oo (or "First lntermedate" 100.00 (or "Oxygen Barrier" Fifth 7.60 Tie Resin 1 100.00 7.60 Tie Resin 2 100.00 (or "Second Intermediate" Sixth 31.50 HDPE 98.00 29.00 HDPE 98.0 (or "Moisture LDPE/Nucleating 2.00 LDPE/Nucleating Nooo Barrier") Agent Blend Agent Blend Seventh 14.00 EVA 2 45.70 9.50 EVA 2 45.70 (or "inner") LLDPE 54.30 LLDPE 54.30 -50_ TABLE 2 Exam oles 7—8 Weight A) Component Weight A: Weight% Component Weight% of Film of Layer of Film of Layer First 12.90 SB 100.00 14.90 88 98.50 (or "Outer") processing aid Second 21.10—— 13.70 EVA 1 100.00 (or "First Barrier Component") ucleating 2.00 Agent Blend Third 6.80 Polyamide 100.00 7.60 Tie Resin 1 100.00 (or "First Copolym er Intermedate" (or "Oxygen Barrier" Fifth 6.80 Polyamide 100.00 7.60 Tie Resin 1 100.00 (or "Second m er Intermediate" Sixth 17.00 28.50 HDPE (or "Moisture LDPE/Nucleating 2.00 Barrier") LDPE/Nucleating 2.00 Agent Blend Agent Blend Seventh 15.00 EVA 1 100.00 (or "lnner") TABLE 3 Weight A: Component Werght% Weight% ent Weight % Weight% Component Weight% of Film of Layer of Film of Layer of Film of Layer First 11.50—_11.40_—11.50—— (or "Outer'l Hrocessin aid 100.00 Second 14 20 DPE 79.0 23.20__13.2oTie Resin 4 (or "First ie Resin 3 20.0 LDPEINucleating 2.00 Barrier LDPE/Nucleating 1 00. Agent Blend Component") Agent Blend Third 100.00 ' 7.00 Polyamide 100.00 Tie Resin 1 100.00 7.00 Polyamide (or "First Copoiym er Copoiymer lntermedate" Fourth 22.00 EVOH 100.00 21.80 EVOH 100.00 25.10 EVOH 100.00 (or "Oxygen Barrier" 100.00 Fifth 7.00 ide 100.00 Tie Resin 1 100.00 7.00 Poiyamide (or "Second Copoiymer mer Intermediate" Sixth 13.5O 79.0 24.00 11.50 Tie Resin 4 100.00 (or "Moisture Tie Resin 3 20.0 LDPE/Nucleating 2.00 Barrier“) 'LDPE/Nucleating _\ ODOO. Agent Blend Agent Blend Seventh 24.80 HDPE 97.00 5.80 Polypropylene 100.00 24.70 HDPE (or "lnner") processing aid OC) Copolymer Hydrocarbon Resin LDPE/Nucleating 1.00 LDPE/Nucleating 1 .00 Agent Blend Agent Blend As noted in TABLE 1, the blown films included in the chlorine-free ing sheets of Examples 2-5 are identical; and, as noted in TABLE 2, the blown films included in the chlorine-free packaging sheets of Example 7—8 are cal.

The materials included in the various blown films are as follows: EVA 1 has a reported vinyl acetate content of about 12.8% by weight (of total EVA composition), a reported melt index of about 0.4 g/10 min, a ed density of about 0.934 g/cm3 and a reported peak melting temperature of about 94°C and is commercially available as EscoreneTM Ultra LD 705.MJ from ExxonMobil Chemical Company (Houston, Texas).

EVA 2 has a reported vinyl acetate content of about 26.2% by weight (of total EVA composition), a ed melt index of about 2.3 g/10 min, a reported y of about 0.951 g/cm3 and a reported peak melting temperature of about 74°C and is commercially available as neTM Ultra LD 768.MJ from ExxonMobil Chemical Company (Houston, Texas).

EVOH has a reported ethylene content of about 38 mole percent, a reported density of about 1.17 g/cm3 and a reported melting point of about 173°C and is commerciaity available as l® ET3803 from Soarus L.L.C. (Arlington s, Illinois).

HDPE has a reported melt index of about 2.0 g/10 min and a reported density of about 0.960 g/cm3 and is commercially available as Alathon® M6020 from Equistar Chemicals LP (Houston, Texas). _15 Hydrocarbon Resin is an amorphous, lecular-weight hydrocarbon resin derived from aromatic petrochemical feedstocks, has a reported ring and ball softening point of about 140°C and a reported density of about 0.98 g/cm3 and is commercially available as Plastoiyn® R1140 Hydrocarbon Resin from Eastman al Company (Kingsport, Tennessee).

LDPE/Nucleating Agent Blend is a ying agent masterbatch having a reported specific gravity of about 0.93 and is commercially available as Polybatch® CLR122 from A. Schulman Inc. (Akron, Ohio). 0.918 LLDPE comprises butene LLDPE resin, has a reported density of about g/cm3, a reported melt index of about 1.0 g/10 min, a reported peak g ature and is commercially of about 121°C and a reported crystallization point of about 106°C available as ExxonMobil LLDPE LL1001.32 from ExxonMobil Chemical Company (Houston, Texas). of about Polyamlde Copolymer comprises nylon 6/6,6, has a reported density 1.129/cm3 and a reported melting point of about 193°C and is commercially available as Ultramid® C40 L 01 from BASF ation (Florham Park, New Jersey). flow of opylene Copolymer is an impact copolymer, has a reported melt and a reported melting about 0.75 9/10 min, a reported density of about 0.905 g/cm3 point range of about 160°C-165°C and is commercially available as Propylene 4170 from Total Petrochemicals USA, inc. (Houston, Texas). and e Processing aids used vary depending on the equipment used Such aids are antibiock , slip agents, stabilizing agents and release agents. t undue known to a person of ordinary skill in the art and may be ined experimentation. melt flow rate SB has a reported specific gravity of about 1.02 g/cm3, a reported of about 61°C (200°C/5.0 kg) of about 10.0 g/10 min and a reported vicat softening point from and is commercially available as DK13 K-Resin® Styrene Butadiene Copolymers Chevron Phillips Chemical Company LP (The Woodlands, Texas).

Tie Resin 1 comprises ide-modified LLDPE resin, has a reported density of about 1.7 g/10 min, a of about 0.91 g/cm3, a reported melt flow rate (190°C/2.16 kg) of about 84°C reported melting point of about 119°C and a reported vicat softening point and is commercially available as DuPontTM Bynel® 41 E687 from El. du Pont de Nemours and Company, lnc. (Wilmington, Delaware).

Tie Resin 2 comprises ide-modified LLDPE resin, has a reported density of about 0.93 g/cm3, a reported melt flow rate (190°C/2.16 kg) of about 1.2 g/10 min, a reported melting point of about 127°C and a reported vicat softening point of about 110°C and is commercially available as DuPontTM Bynel® 4164 from El. du Pont de Nemours and Company, lnc. (Wilmington, Delaware).

Tie Resin 3 comprises anhydride-modified LLDPE resin, has a reported density of about 0.91 g/cm3, a reported melt flow rate (190°C/2.16 kg) of about 2.7 g/10 min, a IO reported melting point of about 115°C and a reported vicat softening point of about 103°C and is commercially available as DuPontTM Bynel® 41 E710 from El. du Pont de Nemours and Company, Inc. (Wilmington, Delaware).

Tie Resin 4 comprises maleic anhydride-modified LLDPE resin, has a reported melt index of about 1.0 g/10 min and a reported density of about 0.9200 g/cm3 and is commercially available as GT4157 from ke Chemical Corporation (Houston, Texas).

In making the blown films of Examples 1-8 and Comparative Examples 1, 5 and 6, one extruder is used for each layer. If a layer comprises more than one thermoplastic resin (as in, for example, the first, sixth and seventh layers of Example 1), the resins for that tayer are pre-blended prior to being added to the er. The layer ents are then heated to form streams of melt-plastified rs and extruded h a die.

The coextruded plastified, extruded components then form a tubular ate (or bubble). The outer layer of the blown film is the outermost layer of the tubular extrudate; the inner layer of the blown film is the innermost layer of the tubular extrudate. The diameter of the tubular extrudate is expanded by air entering the extrudate at the die. The approximate die diameter, lay-flat width of the expanded tubular ate and blow-up ratio (i.e., the ratio of the diameter of the expanded tubular extrudate to the er of the die) used to produce the blown films of Examples 1-8 and Comparative Examples 1, 5 and 6 are shown in TABLE 4.

TABLE4 —l-lll—inches inches -—--__— The expanded tubular extrudate is then collapsed by a collapsing frame and flattened through nip rolls. in the collapsing and flattening, two inner tubular ate layers are formed.

For Examples 1-8. the blown film ent is ed at a high enough output rate (as determined by a person of ordinary skill in the art without undue experimentation) so that the collapsed, flattened r extrudate is of a sufficient temperature to laminate to itself at the two inner tubular extrudate layers. In laminating to themseives, the two inner r extrudate layers form one inner layer and a palindromic thirteen-layer film results.

For Comparative Examples 1, 5 and 6, the collapsed, flattened tubular extrudate is not laminated to itself at the two inner tubular extrudate layers. For these comparative examptes, the tubular extrudate is slit into two seven-layer films.

For the thirteen-layer films of Examples 1-8, the first surface of each en- layer film is then extrusion coated with a rigid component. After the first surface is ion coated with a rigid component, the second surface is extrusion coated with a rigid component. For the seven-layer films of Comparative Examples 1, 5 and 6 only the first surface (i.e., the surface comprising EVA) is extrusion coated with a rigid component. The rigid ents have the compositions (by approximate weight percent) shown in TABLE 5. _ Q U ' Second Rigid Component HIPSi HlPSZ PPSi G 2 Color Processing HIP81 HIPSZ GPPS 1 GPPSZ Color Processing Concentrate Aid Concentrate Aid _-_—_--__---- _--_—---20.15%-_— ___--__----— —--_—-----__ _------_--_— _--__-_----—_ _--__—-75.45%---—_ —--—_--75.40%-21.50%-__ Comparative 76.00% 20.00% 2.80% 1.20% not applicable Example 1 Comparative 76.00% 20.00% 2.80% 1.20% not applicable Example 5 Comparative 97.20% 2.80% not applicable Example 6 The cempositions shown in TABLE 5 may be achieved by a blend of s layers comprising HIPS, GPPS, coior concentrate and processing aid. For example, for e 2, each of the first rigid component and the second rigid component ses three layers. The first iayer comprises 73.50% by weight (of the first layer) HtPS 1, 20.50% by weight GPPS 1, 4.00% by weight color concentrate and 2.00% by weight processing aid; the second layer comprises 76.00% by weight (of the second layer) HIPS 1, 20% by weight GPPS 1 and 4.00% by weight color concentrate; and the third layer comprises 73.50% by weight (of the third layer) HIPS 1, 20.50% by weight GPPS 1, 4.00% by weight color concentrate and 2.00% by weight sing aid. Taken together, these three layers result in a first rigid component and a second rigid component each with the ition shown in TABLE 5.

As noted in TABLE 5, for Examples 1-8 the same rigid component is used for each surface of the thirteen-layer film (i.e., for both the first rigid component and the second rigid component). Also, the rigid component used for Example 2 is identical to the rigid component used for Example 3, the rigid component used for Example 4 is identical to the rigid component used for Example 5, and the rigid components used for Exampies 2 and 3 are substantially similar to that used for Examples 4 and 5. As noted by the “not applicabie," Comparative Examples 1, 5 and 6 have only a first rigid component (i.e., are extrusion coated only on the surface comprising EVA).

The materials ed in the various rigid components are as follows: Color concentrates are chosen based on the desired color of the chlorine-free packaging sheet. Such concentrates are known to a person of ordinary skill in the art and may be determined without undue mentation.

GPPS 1 is a crystal (i.e., genera! purpose) polystyrene, has a reported melt flow /5 kg) of about 9.0 g/10 min, a ed vicat softening of about 101°C and a reported density of about 1.04 g/cm3 and is commercialiy available as Crystal Polystyrene 5258 from Total Petrochemicals USA, inc. (Houston, Texas).

GPPS 2 is a crystal (l.e., general purpose) polystyrene, has a reported melt flow (200°C/5 kg) of about 9.09/10 min, a reported vicat softening of about 101°C and a reported density of about 1.04 g/cm3 and is commercially available as Crystal Polystyrene 5248 from Total Petrochemicals USA, Inc. (Houston, Texas).

HIPS 1 is a high impact polystyrene, has a reported melt flow (200°C/5 kg) of about 3.0 g/10 min, a reported vicat softening of about 102°C and a reported density of about 1.04 g/cm3 and is commercially available as Impact Polystyrene 8255 from Total Petrochemicals USA, Inc. (Houston, Texas).

HIPS 2 is a super high impact polystyrene, has a reported melt flow (200°C/5 kg) of about 3.5 g/10 min, a reported vicat softening of about 98°C and a ed density of about 1.04 g/cm3 and is commercially available as Impact Polystyrene 945E from Total Petrochemicals USA, Inc. on, Texas).

Processing aids vary depending on the equipment used and include antiblock agents, slip , stabilizing agents and release agents. Such aids are known to a person of ry skill in the art and may be determined without undue experimentation.

As ned above, Comparative es 2, 3 and 4 were obtained.

Comparative Example 2 is a fully coextruded nine-layer sheet having the following structure: HIPS / tie / HDPE ltie / EVOH ltie / HDPE / tie / HIPS. Comparative Example 3 is a fully coextruded five-layer sheet having the following structure: HIPS / HDPE / EVOH / HDPE / HIPS. And comparative Example 4 is a fully uded five- layer sheet having the following structure: PPS / EVA/ PVdC / EVA/ HIPS+GPPS. (For these sheets, “l” is used to indicate the iayer boundary.) As futly coextruded sheets, the rigid components (i.e., HIPS or HiPS+GPPS) are extruded with the other layers and not coated on or laminated to a previously produced film (as in Examples 1-8 and Comparative Examples 1, 5 and 6). es 1-8 and ative Examples 1-6 were tested for various properties. in measuring the various ties, the thicknesses of the overall sheet, of the blown film, of the blown film’s barrier components and of the sheet’s rigid components may be considered. These thicknesses, listed in mil, for each of the es and comparative examples are shown in TABLE 6.

TABLE 6 Overall Biown Moisture Barrier First Rigid Second Rigid (I) 3' CDet Film Com «onents Corn oonents Com orient Com . onent Exam ale 1 3 5 not relevant 9.75 9.75 Exam ole 2 NNM (no:—l 3 5 1.65 9.75 9.75 Exam ole 3 3 5 not relevant 8.75 8.75 Exam ole 4 18.5 3.5 not relevant 7.5 ‘1 ()1 Exam ole 5 3 5 6.75 not relevant 6.75 Exam ole 6 |\)|’\?I\JI\J—‘k OVQUWUINI 4 not relevant 10.5 10.5 Examle 7 3 5 1.00 10.75 10.75 Exam ole 8 3 5 1.00 9.75 9.75 Comparative 4 not relevant not relevant 21 not applicable Exam ole 1 Comparative 25 not applicable not relevant Exam u le 2 Comparative 25 8.00 m 01 ExamoleS Comparative 25 1.30 A. N 10.5 Exam . Ie 4 Comparative 25 4 -0.70 not relevant not applicable Exam le 5 Comparative 25 4 .83 0.85 not appiicable Exam nle 6 A thickness is listed as “not applicable" if the sheet does not contain a blown film (as in Comparative Examples 2, 3 and 4) or a second rigid component (as in Comparative es 1, 5 and 6). A thickness is listed as “not relevant” if the r property was not determined for that example (as the oxygen transmission rate was not measured for Examples 1, 3, 4 and 5 and Comparative Examples 1 and 2 and as the water vapor transmission rate was not measured for Examples 1, 3, 4, 5 and 6 and Comparative Examples 1, 2, and 5).

Properties measured include the properties described beiow, with a reference to an ASTM Standard Test Method. Each standard test method referenced below is incorporated in its entirety in this application by this reference.

Combined Tear initiation and Propagation Resistance is a measure of the force required to both initiate and ate (or continue) a tear in a plastic fiim or sheet. To determine this force, both energy to break and eiongation are ined in both the machine direction and the transverse (or cross) direction of the sheet. Energy to break is expressed in in*lbf (or “inch pounds” or “pounds inch") and elongation is expressed as a percentage, and both are measured in accordance with ASTM D1004, “Standard Test Method for Tear ance (Graves Tear) of Plastic Film and Sheeting.” For this application, both ements are normalized as per one mil of the packaging sheet thickness.

Tear Propagation ance is a measure of the force required to propagate (or continue) a tear in a plastic film or sheet. To determine this force, both energy to break and peak load are determined in both the machine direction and the transverse (or cross) direction of the sheet. Energy to break is sed in in*lbf (or “inch pounds” or “pounds inch") and peak load is expressed in lbf (or “pound force”), and both are measured in ance with ASTM D1938, “Standard Test Method for Tear- Propagation Resistance (Trouser Test) of Plastic Film and Thin Sheeting by a Single— Tear Method." For this appiication, both measurements are normalized as per one mil of the packaging sheet thickness.

Oxygen Transmission Rate (OTR) is a measure of the rate of the transmission of oxygen gas through plastics in the form of film, ng, laminates, coextrusions, etc. It is expressed in ems/100 in2/day and is measured in accordance with ASTM D3985, “Standard Test Method for Oxygen Gas Transmission Rate h Plastic Film and Sheeting Using a Coutometric Sensor.” For Examples 2, 6, 7 and 8 and ative Examples 3- 6, the ed value is normalized as per one mil of thickness of the oxygen barrier material (i.e., PVdC or EVOH) in the packaging sheet tested, such that an oxygen transmission rate for a sheet expressed as 0.1 cc-mil/1OO in2/day refers to 0.1 cc of oxygen transmitted h one mil of oxygen barrier in a 100 inZ-size sheet per day. For Examples 4a — 7a and Comparative Examples 8a — 9a, the measured value is normalized as per one mil of thickness of the film, such that an oxygen transmission rate for a sheet expressed as 76.8 cc—mil/100in2/day refers to 76.8 cc of oxygen transmitted through one mil of film in a 100in2-size sheet per day. For Examples 4a — 7a and Comparative Examples, 8a — 9a, OTR was measured at 73°F and 0 % relative humidity.

Water Vapor Transmission Rate (WVTR) or Moisture Vapor Transmission Rate (MVTR) is a measure of the rate of the transmission of water vapor or moisture through flexible r materials. It is expressed in g/100in2/day and is measured in accordance with ASTM F1249, “Standard Test Method for Water Vapor Transmission Rate Through Plastic Film and Sheeting Using a Moduiated ed Sensor." For Examples 2, 7 and 8 and ative Examples 3, 4, and 6, the ed value is normaiized as per one mil of thickness of the moisture barrier material (i.e., PVdC or HDPE) in the packaging sheet tested, such that a water vapor transmission rate for a sheet expressed as 0.15 mil/100 inzlday refers to 0.15 g of water transmitted through one mil of moisture barrier in a 100in2-size sheet per day. For Examples 1a — 10a and Comparative Examples 1a — 10a, the measured value is normalized as per one mil of thickness of the film, such that a re vapor transmission rate for a film expressed as 0.254 g—mil/1OO in2/day refers to 0.254 g of moisture transmitted through one mil of film in a 100in2-size sheet per day.

The measured values of the various properties of Examples 1-8 and Comparative es 1-6 are reported in TABLE 7 and in TABLE 8. Each value is an average of at least two measurements.

(The “**” in TABLE 7 and TABLE 8 are explained as s: For Examples 2-5, the Combined Tear Initiation and Propagation Resistance and the Tear Propagation Resistance were determined by measuring the values for at least three samples of each ing sheet and then averaging the at least twelve data points. This approach was selected as Examples 2-5 only vary by the thicknesses of the first rigid component and the thicknesses of the second rigid component; the compositions of the first rigid components, the compositions of the second rigid component and the itions and the thicknesses of the thirteen~|ayer films are either substantially similar or cai.

For Example 2, the Normaiized Oxygen Transmission Rate is assumed to be at least equal to (if not less than) the Normalized Oxygen Transmission Rate for Example 7, as the itions and thicknesses of the oxygen barrier layers are identical.) TABLE 7 Tear Propa-ation Resistance .,_.-..,,,. Wa'fi . .

Mach eD on Transverse ion Machine Direction Transverse Direction Normalized Normalized Normalized Normalized Normalized Normalized Normalized Normalized Energy to Break Elongation Energyto Break Elongation Energy to Break Peak Load Energy to Break Peak Load (in‘lbf/ mil) (°o / mil) f / mil) (% / mil) (in*lbf/ mil) (lbf I mii) f/ mil) (lbf Imil) Example1 0123 Examples 2-5“ 0.133 Exam'IeG 0.138 Example 1 0 101 0.432 0.116 0 827 0 176 0.114 0.304 0.149 Example 2 0 260 1.184 0.432 1.812 0.497 0.269 0.493 0.345 Example3 0.127 0.440 not determined not determ. 0.264 0.141 0.366 0.237 Example 4 0.071 0.296 0.072 0.330 0.112 0.062 0.090 0.076 TABLE 7 reports the normalized combined tear initiation and propagation ance and the normalized tear propagation resistance for the ing sheets of Examples 1-6 and Comparative Examples 1-4. As reported in TABLE 7, each of the sheets exemplifying the present invention has a normalized combined tear initiation and propagation resistance in both the machine direction and the erse direction of less than about 0.115 in*lbf/ mil energy to break and less than about 0.800 % / mil elongation, and has a normalized tear propagation ance in both the machine direction and the transverse direction of less than about 0.300 in*lbf/ mil energy to break and less than about 0.145 lbf/ mil peak load. The packaging sheets of Comparative Examples 1-3 exceed the normalized combined tear initiation and propagation resistance and the normalized tear ation resistance achieved by the ne-free packaging sheets Examples 1-6 and, therefore, do not exemplify the present invention. The packaging sheet of Comparative Example 4 achieves similar tear resistance vaiues as the chlorine-free packaging sheets of Examples 1-6.

However, this sheet is not chlorine-free (as it inciudes PVdC) and, therefore, does not exemplify the present invention.

.As Shown by the following observations, lower tear resistance numbers correlate to an ease of processing the packaging sheet. (And lower oxygen or water vapor transmission rates have no correlation to ease of processing.) The chlorine-free ing sheet of e 1 was thermoformed into a cup and filled with a liquid product. Sticking of the sheet to the contact heater plate was observed, resuiting in sealing issues. However, the sticking was attributed to the processing aid in the rigid component and not due to the overall structural components (e.g., rigid component(s) and multilayer film) of the chlorine-free packaging sheet.

The chlorine-free packaging sheet of Example 2 was thermoformed into a cup and filled with a liquid product. No ng, forming, cutting, filling or sealing issues were ed.

The ne-free packaging sheet of e 3 was thermoformed into a cup and filled with a liquid product. No sticking, forming, cutting, filling or sealing issues were observed.

The chlorine-free packaging sheet of Example 5 was thermoformed into a cup and filled with a liquid product. No sticking, forming, cutting, filling or sealing issues were observed.

The chlorine-free ing sheet of Example 7 was thermoformed into a cup and filled with a liquid product. No significant sticking, forming, g, filiing or sealing issues were observed. -65..

The chlorine-free ing sheet of Example 8 was thermoformed into a cup and filied with a liquid product. No sticking, forming, cutting, filling or sealing issues were observed.

The packaging sheet of Comparative Example 1 was formed into a cup and filled with a liquid product. Moderate sticking of the sheet to the contact heater plate was observed. In filling the cup with the liquid product, the moderate sticking caused the sheet to ripple and the product to splash out of the cup. The sticking was attributed to the seven-layer blown film used in the packaging sheet and to the absence of a second rigid component.

The packaging sheet of Comparative Example 5 was thermoformed into a cup and filled with a liquid product. Some splashing of the product was observed. The splashing was uted to the sticking of the sheet to the contact heater piate, which and to the was attributed to the seven-layer blown film used in the packaging sheet e of a second rigid component.

The packaging sheet of Comparative Example 6 was thermoformed into a cup and filled with a liquid product. Some ng of the sheet to the contact heater plate and small ers left after trimming (i.e., cutting) were both observed. These were attributable to the seven-layer blown film used in the packaging sheet and to the absence of a second rigid component. —66- TABLE 8 Normalized Normalized Oxygen Transmission Rate Water Vapor Transmission Rate (cc-mil/100in2/day) (g-mil/1 00in2/day) Example 2 “'0 0608 0.1172 Exam sle 6 0 0625 not ined Examole 7 0 0608 0.0966 Example 7 - Thermoformed Cup 0 0299 0.0036 Example 8 0.078 Com arative Exam . le 3 0.3056 Com-arative e 4 0.0456 Comparative e 4 -- Thermoformed Cup 0.0970 0.0129 Comparative Exam ale 5 nOt determined Com oarative Exam ale 6 0.0827 Comparative Example 6 - Thermoformed Cup 0.0634 0.0025 TABLE 8 reports the normalized oxygen ission rate for the packaging sheets of Examples2, 6, 7 and 8 and Comparative Examples 3—6. TABLE 8 further reports the normalized water vapor ission rate for the packaging sheets of Examples 2, 7 and 8 and Comparative Examples 3, 4 and 6. Additionally, the packaging sheets of Example 7, Comparative Example 4 and Comparative Example 6 were thermoformed into cups and also measured for oxygen transmission rate and water vapor transmission rate. The oxygen transmission rates for the packaging sheets of Example 2, 6, 7 and 8 and Comparative Examples 3-6 were measured at about 23°C, 80% internal relative humidity and 80% external relative humidity. The water vapor transmission rates for the packaging sheets of Example 2, 7 and 8 and Comparative Examples 3, 4 and 6 were measured at about 38°C, 0% internal relative humidity and 90% al relative humidity. The oxygen ission rates for the thermoformed cups of the packaging sheets of Example 7, Comparative Example 4 and Comparative Example 6 were measured at about 23°C, 80% internal relative humidity and 50% al relative ty. The water vapor transmission rates for the thermoformed cups of the packaging sheets of Example 7, Comparative Example 4 and Comparative Example 6 were measured at about 38°C, 0% al relative humidity and 50% external relative humidity.

As reported in TABLE 8, each of the sheets (and thermoformed cup) exemplifying the present invention has a normalized oxygen transmission rate of less than about 0.1 /100 in2/day and a ized water vapor transmission rate of less than about 0.15 g-mil/100 inzlday. The packaging sheet of Comparative Example 3 exceeds the normalized oxygen transmission rate and the normalized water vapor transmission rate achieved by the chlorine-free packaging sheets (and thermoformed cup) of Examples 2, 6, 7 and 8 and also exceeds the ized ed tear initiation and propagation resistance and the normalized tear propagation resistance achieved by the chlorine—free packaging sheets of Examples 1-6; therefore, Comparative Example 3 does not exemplify the t invention. The packaging sheet (and thermoformed cup) of Comparative Example 4 es similar transmission rates as the chlorine—free packaging sheets (and thermoformed cup) of Examples 2, 6, 7 and 8. However, this sheet is not chlorine-free (as it es PVdC) and, therefore, does not exemplify the present invention. The ing sheet of Comparative Example 5 achieves similar oxygen transmission rates as the chlorine-free ing sheets (and thermoformed cup) of Examples 2, 6, 7 and 8. However, as noted above, this sheet had processing issues attributable to structural components (i.e., the multilayer film and the absence of a second rigid component) of the packaging sheet. The packaging sheet (and thermoformed cup) of Comparative Example 6 achieves similar transmission rates as the packaging sheets (and thermoformed cup) of Examples 2, 6, 7 and 8 (albeit the oxygen transmission rate for the packaging sheet of Comparative Example 6 is somewhat higher). However, as noted above, this sheet had processing issues utable to structural components (i.e.. the multilayer film and the absence of a second rigid component) of the packaging sheet.

Examples 1a — 10a are non-oriented films also exemplifying the present invention. ative Examples 1a — 10a were also ed. Example 1a and Comparative Examples 2a — 5a were extruded as monolayer films on a Labtech Engineering cast extrusion line. Examples 23 — 10a and Comparative es 63 — 10a were produced, generally, as follows: A multilayer, blown, coextruded film was produced and thermally laminated to itself at the inner layers. atively, the coextruded film was slit open-into one or more films.

TABLE 9 reports the normalized water vapor transmission rate for the monolayer films of e 1a and Comparative Examples 1 a-4a. The moisture vapor transmission rates for the films of Example 1a and Comparative Examples ta — 5a were measured at about 100°C and 90 % external relative humidity. Example ta comprises 83 % by weight M6020 HDPE, 15 % by weight hydrocarbon resin and 0.08 % by weight nucieating agent; the normalized moisture vapor transmission rate for this film is 0.254 g-mil/100in2/day. By comparison, Comparative Example 1a comprises 100 % by weight M6020 HDPE and has a greater normalized moisture vapor transmission rate of 0.396 100in2/day. The addition of 0.08 % by weight nucleating agent to M6020 HDPE decreases the normalized moisture vapor transmission rate to 0.351 g-mil/1 00in2/day as shown in Comparative Example 2a. The addition of 15 % by weight hydrocarbon resin to M6020 HDPE increases the ized moisture vapor transmission rate to 0.434 g- mil/100in2/day as shown in Comparative Example 3a. Thus, the nucleating agent and hydrocarbon resin have opposing effects on the normalized moisture vapor transmission rate. When the nucleating agent and hydrocarbon agent are combined as in Example 1a, a synergistic effect is observed. Example 13 has a lower normalized re vapor transmission rate than any of Comparative Examples 1a-3a, including Comparative Example 2a which comprises the nucleating agent. Thus, the effect of adding a nucleating agent and hydrocarbon resin in combination is not predicted based on the results of the nucleating agent and hydrocarbon resin alone and, therefore, is a surprising result.

Comparing Comparative Examples 4a and 5a illustrate that, although a ion in normalized re vapor transmission rate is observed with polypropylene instead of M6020 HDPE, the magnitude of the effect is smaller and therefore does not predict the results rated in Example 1a.

TABLE 9 - Plastolyn R1140 Alathon M6020 Polypropylene hydrocarbon HPN-ZOE HDPE resin ting agent Thickness MVTR Normalized MVTR (% by weight) ( 'g ) (% by ) (% by weight) ( y (mils) (gliOOinZ/day) (g—mil/1 00in2/da ) _—_ . 6 0061—.

---Exampleia 100 “m -m-Example2a ---Example3a 85 m— --Example4a 3. ative- Example 53 1.92 The moisture vapor transmission rates for the films of TABLES 10-14, were measured at about 100 °F and 90 % external relative humidity.

TABLE 10 illustrates 1.75 mil collapsed blown films with a total ess of approximately 3.5 mil and en layers. In Example 2a and Comparative Example 6a, layers six and eight se M6020 HDPE and nucleating agent. Example 2a differs from Comparative Example 6a in that layers six and eight of Example 2a further se Piccolyte® 8135 hydrocarbon resin. Example 2a has an improved normalized moisture vapor transmission rate of 0.22 g-mil/100in2/day as compared to Comparative Example 6a which has a normalized moisture vapor transmission rate of 0.23 g- mil/100in2/day.

TABLE 11 reports different collapsed blown films of about 10 mil total ess and thirteen layers. Example 3a differs from Comparative e 7a in that layers two, four, six, eight, ten, and twelve of Example 3a comprise M6020 HDPE in combination with hydrocarbon resin and nucleating agent while layers two, four, six, eight, ten, and twelve of Comparative Example 7a do not comprise Piccolyte® S135 hydrocarbon resin. As shown in TABLE 11, Example 3a affords a reduced normalized moisture vapor ission rate of 0.22 g-mil/100in2/day as compared to Comparative Example 7a, which affords a normalized re vapor transmission rate of 0.35 g~ mil/1005n2/day. in further embodiments, a polyethylene terephthalate, such as PETG, or another rigid component (as described above) may be coated on either or both sides of the film of Example 3a.

TABLE 10 Com arative Exam -!e 6a Weight % Weight % of Weight % of Component Weight % of Film La er Film of La er First 4,75 e 95.50 4.75 Styrene 95.00 butadiene butadiene co-ol mer cool mer O Pol st rene l01'O thermal stabilizer- thermal 0.50 stabilizer Second 1200— 79 00 12.00 Alathon M6020 84.00 HDPE IU'0 [TI O LLDPE 15.0o —_m l—DPE .h HPN-ZOE 100.00 100.00 100.00 Sixth 1 —4.50 Alathon M6020 14.50 Alathon M6020 99.00 HDPE HDPE O l—U '0 lTl _.I=E A HPN-2OE 0.04 Seventh 9.50——D 9.50 I—LDPE 40.0 a).0 ooo Eighth 14 50 Alathon M6020 14.50 Aiathon M6020 co$90o HDPE O l‘I00‘U'ul'l'lrn —_EE 0. & E Twelfth 12.00 12.00 Alathon M6020 ooooo5‘9??? 000A HDPE IU'Um _-m —-E§ Thirteenth 4.75 Styrene 95.50 4.75 Styrene 95.00 butadiene butadiene cool mer co.ol mer stabilizer (mils) (9/1 00in2/day) (g-mil/100in2/day) .

, ”Bi-1511 .

Com oarative Exam ule 7a Weight % -Weight% of Weight %0- Weight % of Film La er Film of La er First —-ma _-§Eil \J 01O HDPE HDPE -—m -m HDPE HDPE —-m -W Fifth a00-. 100.00 8.00-100.00 Sixth 5.50 Alathon M6020 009NO 5.50 Alathon M6020 99.00 HDPE HDPE """""Piccol e S135 14.8O DPE -LDPE —HPN-20E .o O-b —HPN-ZOE 0.04 h 12% EVA 12% EVA 50.0o 28% EVA 28% EVA 50.00 Eighth 5.50 Alathon M6020 84.20 5 50 Aiathon M6020 <05°oo HDPE HDPE Piccol e S135 14.80 LDPE LDPE HPN-20E HPN-ZOE _l Ooo OOCh 8.00 LLDPE d 09.0 oo0&- Tenth 9.50- 00A NO. 9 50 Alathon M6020 co$9oo HDPE HDPE LDPE - _.E§ HPN—ZOE A o.09 oo04:- Twelth 7.50 7.50 Alathon M6020 (D.‘0 oo HDPE HDPE Piccol e 8135 14.80 LDPE LDPE m - HPN-20E E O O. 4: Thirteenth 28% EVA LLDPE 35.00 LLDPE 35.0 antiblock 4.00 antibiock 5‘0oo 9.89 9 4 (mils) (gl100in2/day) (g-mil/100in2/day) TABLE 12 s three layer films with approximately 1.5 mil thickness.

Example 4a is a fiim with a third layer blend containing nominally 85 % by weight M6020 HDPE, 15 % by weight Regalite® T1140 hydrocarbon resin and 800 ppm (0.08 % by weight) nucleating agent. The hydrocarbon resin was compounded into the M6020 HDPE at 15 % by weight prior to extrusion. This compound was blended with a nucleating agent masterbatch (e.g., Polybatch® CLR 122 comprising LDPE and calcium hexahydrophthalate) at the film line and extruded in the third layer of the film. The same film ure was run with both unmodified M6020 HDPE (Comparative Example 9a) thinned to 1.5 mil and M6020 HDPE combined with nucleating agent (Comparative Example 8a). A ized moisture vapor transmission rate measured after one week shows a barrier improvement of 20% for the HDPE M6020 with nucleating agent (Comparative Example Be) as compared to unmodified M6020 HDPE (Comparative Example 9a), and a barrier improvement of 50% for the blend of M 6020 HDPE, arbon resin and nucleating agent le 4a) as compared to unmodified M6020 HDPE (Comparative Example 9a) (all values normalized for gauge). Without wishing to be bound by , it is believed that the nucleation acts on the crysta! phase, and the hydrocarbon resin reduces the free volume in the amorphous phase, leading to the additive effect of the two technologies.

TABLE 12 -Weight% Weight % Weight % Weight % eight % of Film of La er of Film of La er of Film of La er 17.70 Surlyn 96.00 17.70 Surlyn 96.00 14.80 Surlyn (with slip and (with slip and (with slip and antiblock antiblock antiblock % antiblock in 4.00 10% antiblock in 4.00 10% antiblock in 5.00 acid copolymer acid copolymer acid mer Second 62.20 Alathon L5885 100.00 6220 Alathon L5885 100.00 HDPE HDPE 70.20--HDPE Third 20.10-- 20.10-- 15.10 Alathon M6020 HDPE HDPE Reallte T1140 Thickness for MVTR (mils) MVTR (g/100in2/day) Normalized MVTR (g-mil/100in2/day) Thickness for MVTR after 1 week mils) MVTR after 1 week (gl100in2/day) Normalized MVTR after 1 week (g-miI/100in2lday —mils) (cc/100in2/day) ized OTR (cc-milllOOinZ/day) .

TABLE 13 reports additional three layer films with approximately 1.5 mil thickness. The films of TABLE 13 have an ionomer/HDPE/HDPE blend structure. The first and second layers of each of the films in TABLE 13 are the cal. The third layers (the outer skin ) are different. Comparative Example 10a includes an outer skin layer with 85 % by weight M6020 HDPE and 15 % by weight hydrocarbon resin.

This film has a normalized water vapor ission rate of 0.19 g-mil/100in2/day. The addition of nucleating agent decreases the normalized moisture vapor transmission rate, as shown by Examples 5a, 6a and 7a. Examples 5a, 6a and 7a further illustrate the optimization of the amount of hydrocarbon resin for 0.08 % by weight nucleating agent. Example 5a presents the lowest moisture vapor ission rate reported in TABLE 13. in this example, hydrocarbon resin is present at 10.2 % by weight.

Examples 6a and 7a illustrate that increasing the % by weight of hydrocarbon resin has an undesired effect of increasing the moisture vapor transmission rate. Thus, without wishing to be bound by theory, it is postulated that when the % by weight hydrocarbon resin content is too high, the activity of the ting agent is ed. and the synergistic effect of the hydrocarbon resin and the nucleating agent is minimized.

TABLE 13 Exam-Ia 63 am Wt % Component Wt % Component Wt % o Compone o Wt % Component Wt % of Film of of Film of of Film of of Film of La er La er La er La er First 17.70 Surlyn 95.00 1?.70 Surlyn 95.0 17.70 Surlyn 95.00 17.70 Surlyn 95.00 (with slip and . , (with slip and (with slip and (with slip and antiblock antiblock - antiblock antiblock % antiblock 5.00 10% antiblock 5.00 10% antiblock 5.00 10% antiblock 5.00 in acid in acid in acid in acid cool mer co-ol mer co-ol mer cool mer NNo Alathon L5885 HDPE HDPE . HDPE HDPE Third 7.80 20.10Alathon M6020 78.20 2010-- 20.10-- HDPE HDPE HDPE HDPE .20 RegaliteT1140 19.80 RegaliteT1140 15.00 LDPE 1.92 DPE _x .92 LDPE E 08 HPN-ZOE 08 HPN-20E Thickness for 1.49 MVTR (mils) MVTR (g/1 day) Normalized MVTR (g-mil/100in2/day) Thickness for OTR (mils) (cc/100in2/day) Nomalized OTR (cc-mill100in2/day) ~76- TABLE 14 reports additional three-layer films using different hydrocarbon resins.

Examples 8a and 9a illustrate the use of Piccolyte® S135 and Arkon® P-140 hydrocarbon resins in combination with M6020 HDPE and nucleating agent in the third layer of the film. The normalized moisture vapor transmission rate for each of these films is 0.19 and 0.20 g-mil/100in2/day, respectively. Example 10a illustrates the use of Plastolyn® R1140 arbon resin in combination with M6020 HDPE and nucleating agent in the middle layer of the film; this structure affords a ized re vapor transmission rate of 0.15 g-miI/100/in2/day.

TABLE 14 Wt "/0 Component Wt % Wt % Component Wt % 0 Component 0 of Film of of Film of of Film of La er La er La er First 17.70 Surlyn 95.00 17.70 Surlyn 95.00 9.8 Surlyn 95.00 . (with slip and (with slip‘and (With slip and antiblock antiblock antiblock % antiblock 5.00 10% antiblock 5.00 10% antiblock in acid in acid in acid cool mer cool mer co-ol mer Second 62.20 Alathon L5885 100.00 62.20 Alathon L5885 100.00 70.20 Plastoiyn 15.00 R1140 . —m Third 20.10 Alathon M6020 19.90 Alathon L5885 100.00 HDPE 20.10- 84.00 HDPE yte 3135 20.00 —-m —-m H 39.5 .— Thickness for MVTR mils) -(g/100in2/day) f . g-rnil/100in2/day) The above description, the examples and the embodiments disclosed in the examples and othenlvise are illustrative only and should not be interpreted as limiting.

The t ion includes the description, the examples and the embodiments disclosed; but it is not limited to such description, examples or embodiments.

Modifications and other embodiments will be apparent to those skilled in the art, and all such modifications and other embodiments are intended and deemed to be within the scope of the present invention as defined by the claims.

Claims (20)

What we claim is:

1. A film comprising (A) at least one moisture barrier layer comprising a polymer blend comprising (a) high density polyethylene in an amount from about 69 % about 90 % by weight of the blend, wherein the high density polyethylene has a melt index of at least 1.0 g/10 min and a density greater than 0.958 g/cc; (b) hydrocarbon resin in an amount from about 5 % about 30 % by weight of the blend, wherein the hydrocarbon resin comprises petroleum resins, terpene resins, styrene resins, cyclopentadiene resins, saturated alicyclic resins or blends thereof; and (c) nucleating agent in an amount from about 0.01 % to about 1 % by weight of the blend, wherein the nucleating agent comprises glycerol alkoxide salts, hexahydrophthalic acid salts, similar salts or blends thereof; and (B) at least one additional layer comprising an ionomer, a high density polyethylene, a ter, a styrene ene copolymer or blends thereof; wherein the film has normalized moisture vapor ission rate of no greater than 0.30 g-mil/100 y measured at about 100 °F and 90 % external relative humidity.

2. The film of claim 1, wherein the high y hylene comprises from about 75 % to about 85 % by weight of the blend.

3. The film of claim 1, wherein the hydrocarbon resin comprises from about 5 % to about 20 % by weight of the blend.

4. The film of claim 1, wherein the hydrocarbon resin comprises from about 10 % to about 15 % by weight of the blend.

5. The film of claim 1, n the nucleating agent comprises from about 0.04% to about 0.10% by weight of the blend. ‐ 79 ‐

6. The film of claim 1, wherein the nucleating agent is selected from the group consisting of zinc glycerolate salts and m hexahydrophthalate.

7. The film of claim 1, wherein the moisture barrier layer comprises a polymer blend comprising the high density hylene in an amount from about 72% to about 88% by weight of the blend; the arbon resin in an amount from about 10% to about 20% by weight of the blend; and nucleating agent in an amount from about 0.04% to about 0.10 % by weight of the blend.

8. The film of claim 1 wherein the film has a normalized water vapor transmission rate of less than about 0.30 100 in2/day as measured at about 100 °F and 90 % external relative humidity.

9. The film of claim 1, wherein the film comprises an oxygen barrier material and the film has a normalized oxygen transmission rate of less than about 150 cc-mil/100 in2/day.

10.The film of claim 10, wherein the film has a normalized oxygen transmission rate of less than about 100 /100 in2/day.

11.The film of claim 1, wherein the polyester is a polyethylene terephthalate.

12.The film of claim 1, r comprising a second moisture barrier layer comprising the polymer blend of claim 1.

13.The film of claim 1, wherein the film has a thickness of less than 3.00 mil.

14.The film of claim 1, wherein the film has a thickness of less than 1.70 mil.

15.The film of claim 8, wherein the film has a normalized moisture vapor transmission rate of no greater than 0.20 g-mil/100 in2/day as measured at about 100 °F and 90 % external relative humidity. ‐ 80 ‐

16.The film layer of claim 15, wherein the film has a normalized moisture vapor transmission rate of no greater than 0.15 g-mil/100 in2/day as ed at about 100 °F and 90 % al relative ty.

17.A packaging article comprising the film of claim 1.

18. The packaging article of claim 17, wherein the packaging article is a rigid article or a semi-rigid article.

19.A film according to claim 1 substantially as herein described or exemplified.

20.A packaging article according to claim 17 substantially as herein described or exemplified.