WO2010039375A1 - Film composition with controlled properties - Google Patents

Abstract

The present disclosure relates to a film including at least a first layer having at least one of polypropylene, polypropylene with cavitating agent, and mono-oriented high density polyethylene; said first layer has a density in the range of 0.2 to 0.96 gm/ cm³ and a thickness in the range of about 0.5 to 80 microns, wherein said film has an impact strength equal to or less than 0.236 cm⋅kg_f/μm.

Description

FILM COMPOSITION WITH CONTROLLED PROPERTIES

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The application claims priority from U.S. Provisional Application Serial No. 61/102,227, filed October 2, 2008, the contents of which are incorporated by reference in their entirety.

FIELD OF THE INVENTION

[0002] The present disclosure relates to a novel film having balanced properties, a method of making same, and package structures comprising same. The present film can replace multi-substrate laminates for peel-and-push or push-through blister packaging. The present film, which can be coated, provides all of the beneficial characteristics of a currently commercial laminate, e.g., barrier protection, sealability to the blister package, peelability and fracturability, while at the same time providing better economics and handling ease. BACKGROUND OF THE INVENTION [0003] The current commercial practices for blister packaging involve a variety of lidding structures. The present disclosure involves a single film, e.g., a simplified mono-web structure, having controlled properties of, for example, tear strength, oxygen transmission rate and water vapor transmission rate, to replace the multi-substrate laminates presently used. This single film either has one layer intentionally structurally weakened, or is exposed to radiation, for example gamma radiation, to permit the push-through feature and provide a tamper-evident appearance. The film provides better economics and handling, e.g., mass reduction and lower cost through simplification, while maintaining stiffness and barrier required for such uses. [0004] Current standard lidding material normally consists of aluminum foil. The foil can be hard or soft tempered, depending on the level of push-though ability the manufacturer wishes to achieve. The aluminum foil for this use is usually about 20 microns (μ) in thickness. One side of the aluminum foil receives a lacquer to seal to the blister package which requires a primer, and the other side, usually also primed, is printed. There could be some lamination with other materials such as, for example, paper or polyethylene. Therefore a typical lidding structure involves, in part, a heat seal, aluminum foil, primer, print medium and then lacquer.

[0005] In any event, the following features are important for blister packaging applications: 1. For child-resistant peel-and-push package structures, where a layer has to be peeled off before being able to push an article, such as, for example, a pill through another layer. A usual structure for this application involves a heat seal, a primer, aluminum foil, adhesive, polyethylene terephthalate, adhesive, paper, print, and then lacquer. 2. The main fitness for use criteria for the materials in this structure are push-through ability (measured using an internal fiber tear test, in tear strength of for example from about 79 to about 197 g/cm), barrier to moisture (for example, less than about 1 g/m²/24 hr @ 38⁰C, 90% relative humidity), resistance to elongation (for example, less than about 50%), and sometimes barrier to oxygen (for example, less than about 2 cm³/ m²/24 hr @ 23°C, 0% relative humidity) or barrier to light (for example less than about 1% light transmission).

[0006] U.S. Patent 6,887,334 discloses a process for forming thin film laminations of fluoropolymer films to receiver sheets, more particularly, the production of very thin, transferable fluoropolymer films. A thin fluoropolymer base layer is applied onto a support layer, which may be a thicker film. The support layer/thin base layer is then laminated to a receiver sheet, followed by stripping away the support layer, leaving the base film on the receiver sheet.

[0007] U.S. Patent 6,413,599 discloses a sealed package for an article of personal use. The package includes a plastic container that defines a storage region and has a sealing surface around an entrance to the region. The package also includes a plastic, multi-layer laminate film sealed to the sealing surface of the container. The film is removable from the sealing surface in one piece and has a deadfold characteristic. The laminate film consists of a plurality of plastic layers such as ethylene vinyl acetate copolymer, low density polyethylene, high density polyethylene, polyethylene terephthalate and combinations thereof. [0008] U.S. Patent 5,342,684 discloses a polymeric, die cuttable symmetrical lidding laminate for a container which is heat sealable to and peelable from the container. The laminate structure may comprise a core layer of a biaxially oriented voided polypropylene film to the opposite sides of which first and second outer layers of a nonvoid-bearing biaxially oriented polyester film are adhesively laminated to form a symmetrical laminate structure. A heat seal layer or coating is applied to one side of the laminate structure and a static charge dissipating layer or coating is applied to the other side of the laminate structure. [0009] U.S. Patent 6,161,699 discloses a child resistant blister package for medicaments in pill form including a blister sheet having a pattern of blisters for receiving individual pills and a rupturable lidding foil laminated to the blister sheet covering and sealing the blisters. A reinforcing card having a corresponding pattern of weakened score line punch-outs is laminated to the lidding foil with a punch-out overlying each blister, and a reinforcing film of high strength flexible material laminated to the card using a low peel adhesive. The reinforcing film covers the punch-outs and an area of the card surrounding each punch-out, and has weakening score lines separating the areas overlying each punch-out to enable the reinforcing film to be peeled from the portion of the package overlying the individual punch- outs without disturbing the portion overlying the remaining punch-outs. The adhesive bond between the reinforcing film and the punch-out removes the punch-out upon peeling away of the overlying reinforcing film. [0010] U.S. Patent Application 5,310,06OA discloses a tamper-evident, child-resistant blister package for articles which could be medicaments or non-medicaments. The blister package has pull tabs which are designed to be pulled away from, rather than towards, article- receiving pockets which may be present in the blister package other than the article-receiving pocket being accessed. The top laminate layer is composed of perforated paper or printable film.

[0011] U.S. Patent 5,522,506 discloses lidding film without metal foil for lidding push- through forms of packaging, where the lidding film contains at least one polyolefm-based or polyester-based thermoplastic and the thermoplastic contains 5 to 50 wt.% filler material. With the aid of a sealing layer the lidding film can, if desired, be sealed onto the bottom part of a push-through form of packaging or blister pack. The lidding film is inelastic to such a degree that the packaged contents can be pushed through the film.

[0012] None of these references teach or suggest a single film, e.g., a simplified mono- web structure, to replace the multi-substrate laminates presently useful as lidding material for package structures such as blister packages. There is a long felt need to develop such film to replace the existing blister package structure that is expensive and difficult to manufacture. Accordingly, an object of the present disclosure is to provide a novel film, e.g., a simplified mono-web structure, having controlled properties of, for example, combination of density, impact strength, thickness, tear strength, oxygen transmission rate and water vapor transmission rate. Another object of the disclosure is to provide such a film to replace the multi-substrate laminates presently useful as lidding material for package structures such as blister packages. The film of this disclosure provides better economics, simplified process of manufacturing, and easier handling than multi-substrate laminates presently useful as lidding material and/or the materials disclosed in the above publications/patents. SUMMARY OF THE INVENTION

[0013] In some embodiments, the present disclosure provides a novel film comprising a first layer comprising at least one of polypropylene, polypropylene with cavitating agent, and mono-oriented high density polyethylene; the first layer has a density in the range of 0.2 to 0.96 gm/ cm³ and a thickness in the range of about 0.5 to 80 microns, wherein the film has an impact strength equal to or less than 0.236 cm»kg_f/μm.

[0014] In some embodiments, the film of this disclosure has balanced properties of, for example, tear strength of from about 79 to about 197 g_f/cm; oxygen transmission rate of from about 0 to about 2.1 cm³/m²/24 hours at 23°C and 0% relative humidity; water transmission rate of less than about 1 g/m²/24 hours at 38⁰C and 90% relative humidity; elongation (inelasticity) of less than about 200%; and light barrier (light transmission rate) of from about 0.4 to about 1.1%.

[0015] In some aspects, the film of this disclosure is made of a polypropylene based coextrusion that is highly cavitated. In other embodiments, the highly cavitated polypropylene film further comprises a metallized skin and/or other layers. The film that is highly cavitated would allow easy push-through without requiring a peeling step, giving a push-through structure.

[0016] In other aspect, the film of this disclosure is made of a mono-oriented high density polyethylene (OHD) based coextrusion. An OHD film would allow a push-through structure without requiring a peeling step.

[0017] In yet other aspects, the film of this disclosure is made of a polypropylene based coextrusion that is exposed to sufficient energy to cause chain scission embrittlement. In some preferred embodiments, the film of this disclosure is exposed to sufficient gamma radiation to reduce the tensile strength of the polypropylene (PP), which yields a film having easy push-through property without requiring a peeling step, giving a push-through structure. [0018] In some embodiments, the film of this disclosure relates to a highly cavitated structure that can be made by loading at least one layer, preferably all layers, except the metallized skin with cavitating agent, such as, CaCθ₃, which weakens the impact strength of the film, suitable for push through applications. The following table illustrates layer structure, functions and examples of materials useful to achieve these functions for these embodiments.

[0019] In other embodiments, the film of this disclosure is made by a mono-oriented polyethylene, such as, mono-oriented high density polyethylene. Such a film structure has impact strength suitable for push through applications. The following table illustrates layer structure, functions and examples of materials useful to achieve these functions for these embodiments.

[0020] In yet other embodiments, this disclosure relates to an embrittled polypropylene structure made by exposing the structure to energy source, such as, gamma radiation. The package having the film, such as, blister package, may also be exposed to energy, such as, gamma radiation to create an embrittled polypropylene structure. The following table illustrates layer structure, functions and examples of materials useful to achieve these functions for these embodiments.

[0021] Further, the present disclosure provides an article of manufacture, such as, for example, a package structure, e.g., a blister package, comprising a film, e.g., a simplified mono-web structure, having controlled properties of, for example, tear strength, oxygen transmission rate and water vapor transmission rate. DETAILED DESCRIPTION

[0022] This disclosure relates to a novel film having a unique and controlled combination of properties, e.g., tear strength, oxygen transmission rate and water vapor transmission rate. The film of this disclosure may be useful for replacing multi-substrate laminates for packaging structures, such as, for example, blister packaging. [0023] Various specific embodiments, versions, and examples are described herein, including exemplary embodiments and definitions that are adopted for purposes of understanding the claimed invention. While the following detailed description gives specific preferred embodiments, those skilled in the art will appreciate that these embodiments are exemplary only, and that the invention can be practiced in other ways. For purposes of determining infringement, the scope of the disclosure will refer to any one or more of the appended claims, including their equivalents, and elements or limitations that are equivalent to those that are recited. Any reference to the "invention" may refer to one or more, but not necessarily all, of the inventions defined by the claims. [0024] As used herein, the term "monomer" is a small molecule that may become chemically bonded to other monomers to form a polymer. Examples of monomers include olefmic monomers, such as, ethylene, propylene, butylene, 1-hexene, styrene, and 1-octene, acrylic monomers, such as acrylic acid, methyl methacrylate, and acrylamide, amino acid monomers, and glucose monomers. [0025] As used herein, the term "polymer" refers to the product of a polymerization reaction, and is inclusive of homopolymers, copolymers, terpolymers, etc.

[0026] As used herein, unless specified otherwise, the term "copolymer(s)" refers to polymers formed by the polymerization of at least two different monomers. For example, the term "copolymer" includes the copolymerization reaction product of ethylene and an alpha- olefin (α-olefin), such as 1-hexene. However, the term "copolymer" is also inclusive of, for example, the copolymerization of a mixture of ethylene, propylene, 1-hexene, and 1-octene. [0027] As used herein, unless specified otherwise, the term "terpolymer(s)" refers to polymers formed by the polymerization of at least three distinct monomers. [0028] As used herein, the term "thermoplastic" includes only those thermoplastic materials that have not been functionalized or substantially altered from their original chemical composition. For example, as used herein, polypropylene, ethylene-propylene copolymers, propylene α-olefm copolymers, polyethylene and polystyrene are thermoplastics. However, maleated polyolefϊns are not within the meaning of thermoplastic as used herein. [0029] As used herein, weight percent ("wt.%"), unless noted otherwise, means a percent by weight of a particular component based on the total weight of the mixture containing the component. For example, if a mixture or blend contains three grams of compound A and one gram of compound B, then the compound A comprises 75 wt.% of the mixture and the compound B comprises 25 wt.%. As used herein, parts per million (ppm), unless noted otherwise, means parts per million by weight. [0030] The combination of properties of this novel film is important for the use thereof as blister packaging film. These properties include impact strength measured by ASTM D3420- 95 (2002) Method, Tear Strength measured by the TMI Method, hereinafter described; Oxygen Transmission Rate measured by the ASTM D3985 Method; Water Transmission Rate measured by the ASTM F 1249 Method; Elongation (inelasticity) measured by the ASTM D882 Method; and Light Barrier (light transmission rate) measured by the ASTM D1003 Method. The TMI Method for measurement of Tear Strength involves a TMI Slip/Peel tester, model 32-06, capable of 30.5 cm/min test speed.

[0031] The thickness of the film and the thickness of the film's layers were measured by using an optical gauge Model # 283-20 available from Beta LaserMike, Dayton, OH. The yields of the film were measured using ASTM D-4321 method. The density of the film and/or the density of the film's layers were measured using ASTM D- 1505 method. The Peel Skin Adhesion Data were measured by using a Sintech Tensile tester according to the following procedure: cutting strip 7.62 cm wide in the transverse direction and 30.48 cm long in the machine direction, applying 2.54 cm wide 3M® 610 tape to the test surface (leaving enough tail to allow a folded end to be inserted into the upper jaw of the Sintech tester), loading specimen into the Sintech tester grips making sure that the specimen is straight vertically and with even tension side to side for 90° angle testing (for 180° angle load sample from backside to hold tail against the sample itself for this testing), running the test, reporting angle of pull (90° or 180°) peak strength and average strength. The TLMI Interfacial Adhesion Data were measured by using a TLMI Lab Master Release and Adhesion Tester according to the following procedure: cutting sample to a 5.08 cm minimum width in the transverse direction and at least 15.24 cm in length in the machine direction, setting calibration arm to 135°, calibrating the unit, setting test condition to test sled angle set to 90°, loading cell with angle set to 135° and speed of 3,048 cm per minute, applying two-sided tape to the test platen beginning at 5.08 cm below the top of the platen and between the etched lines, applying film sample evenly with the top and edge of the tape, cutting a length of 3M^® 610 tape, which allows the generation of a 5.08 cm pull-tab while leaving approximately 17.78 cm of exposed adhesive to apply to the visible surface of the 15.24 cm sample, applying the tape to the sample, running test, and reporting peel force average value in grams per sample width. The Z Tear Skin Adhesion Data were measured by using a TMI Slip/Peel tester capable of 30.48 cm per minute test speed equipped with a glass or metal base plate according to the following procedure: cutting a strip 5.08 cm wide in the transverse direction and at least 7.62 cm long in the machine direction, cutting a 7.62 cm length of double-sided tape and carefully applying it to the glass or metal base plate, applying sample to base plate with desired skin surface facing up, placing sample width over tape width on the glass or metal surface, cutting a 15.24 cm length of 2.54 cm wide 3M^® 610 tape and carefully applying to test surface of sample, inserting folded tail into sample clamp, running test, reporting the Z Tear value. The impact strength (Ballburst data) were measured by using a TMI Ball Burst Tester or Dynamic Ball Burst Tester Model 13-B according to the following procedure: cutting each specimen so that it fits into specimen holder and covers test area (approximately 10.16 cm by 10.16 cm square or 10.16 cm circle), measuring thickness of test specimen using optical gauge as described, placing specimen in the specimen holder with machine direction of film parallel with hinge, running test, and reporting impact strength.

[0032] The film of this disclosure has an Impact Strength of equal to and/or less than 0.236 cm*kg_f/μm. In some embodiments, the film of this disclosure has an Impact Strength in the range of 0.00004 cm*kg/μm to 0.236 cm*kg/μm. The following Impact Strength values are useful lower Impact Strength limits: 0.00004, 0.00020, 0.00039, 0.00197, 0.00394, 0.01969, and 0.03937 cm«kg_f/μm. The following Impact Strength values are useful upper Impact Strength limits: 0.039, 0.079, 0.118, 0.158, 0.197, 0.217, and 0.236 cm^»kg_f/μm. The Impact Strength for the use of the present film as blister pack lidding material falls in a range between any one of the above-mentioned lower Impact Strength limits and any one of the above-mentioned upper Impact Strength limits, so long as the lower Impact Strength limit is less than or equal to the upper Impact Strength limit. The Impact Strength for the use of the present film as blister pack lidding material may be in the range of 0.00004 to 0.236 cm»kg_f/μm in one embodiment, alternatively 0.0197 to 0.217cm»kg_f/μm in another embodiment. [0033] The following Tear Strength values are useful lower Tear Strength limits: 79, 89, 98, 108, 118, 128, 138, 148, and 157 grams. The following Tear Strength values are useful upper Tear Strength limits: 118, 128, 138, 148, 157, 167, 177, 187, and 197 g_f/cm. The Tear Strength for the use of the present film as blister pack lidding material falls in a range between any one of the above-mentioned lower Tear Strength limits and any one of the above-mentioned upper Tear Strength limits, so long as the lower Tear Strength limit is less than or equal to the upper Tear Strength limit. The Tear Strength for the use of the present film as blister pack lidding material may be in the range of 79 to 177 g_f/cm in one embodiment, alternatively 79 to 167 g_f/cm in another embodiment. [0034] The following Oxygen Transmission Rate values in cm³/m²/24 hours at 23°C and 0% relative humidity are useful lower Oxygen Transmission Rate limits: 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8 and 1.9.

[0035] The following Water Transmission Rate values in g/m²/24 hours at 38°C and 90% relative humidity are useful lower Water Transmission Rate limits: 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, and 0.9.

[0036] The following Elongation values in the machine direction (MD) are useful lower Elongation limits: 1%, 20%, 50%, 60%, 70%, 80%, 90%, 100%, 120%, and 150%. The following Elongation values in the machine direction (MD) are useful upper Elongation limits: 80%, 90%, 100%, 120%, 140%, 160%, 180% and 200%. The Elongation f in the machine direction (MD) or the use of the present film as blister pack lidding material falls in a range between any one of the above-mentioned lower Elongation limits in the machine direction (MD) and any one of the above-mentioned upper Elongation limits in the machine direction (MD), so long as the lower Elongation limit is less than or equal to the upper Elongation limit. The Elongation in the machine direction (MD) for the use of the present film as blister pack lidding material may be in the range of 1 % to 200% in one embodiment, alternatively 80% to 160% in another embodiment.

[0037] The following Elongation values in the transverse direction (TD) are useful lower Elongation limits: 1%, 10, 20%, 30% 40%, 50%, 60%, 70%, 80%, 90%, and 100%. The following Elongation values in the transverse direction (TD) are useful upper Elongation limits: 20%, 30% 40%, 50%, 60%, 70%, 80%, 90%, 100%, 120%, 140%, 160%, 180% and 200%. The Elongation in the transverse direction (TD) for the use of the present film as blister pack lidding material falls in a range between any one of the above-mentioned lower Elongation limits in the transverse direction (TD) and any one of the above-mentioned upper Elongation limits in the transverse direction (TD), so long as the lower Elongation limit is less than or equal to the upper Elongation limit. The Elongation in the transverse direction (TD) for the use of the present film as blister pack lidding material may be in the range of 40% to 80% in one embodiment, alternatively 40% to 60% in another embodiment. [0038] The following Light Barrier values are useful lower Elongation limits: 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, and 1%. The following Light Barrier values are useful upper Elongation limits: 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1% and 1.1%.

[0039] In some embodiments, the novel film of the present disclosure having a unique and controlled combination of properties is a film comprising first layer comprising at least one of polypropylene, polypropylene with cavitating agent, and mono-oriented high density polyethylene; the first layer has a density in the range of 0.2 to 0.96 gm/cm³ and a thickness in the range of about 0.5 to 80 microns, wherein the film has an impact strength equal to or less than 0.236 cm*kg_f/μm.

[0040] In other embodiments, the novel film of the present disclosure having a unique and controlled combination of properties is a film comprising first layer and at least one of a second layer having thermoplastic, wherein the thermoplastic comprises at least one of polyethylene, polypropylene, ethylene -propylene copolymer, ethylene-propylene-butylene terpolymer, propylene -butylene copolymer and wherein the second layer has a thickness in the range of about 0.50 to 2.0 micron; a third layer comprising a polyolefm having at least one of polypropylene, polypropylene with cavitating agent, and the polyolefin is grafted with a functional group, wherein the third layer has a thickness in the range of about 0.5 to 8 microns; a fourth layer comprising at least one of polylactic acid, ethylene vinyl alcohol polymer, or high density polyethylene, wherein the fourth layer has a thickness in the range of about 0.5 to 2 microns; and a fifth layer having metal, wherein the fifth layer has a thickness in the range of about 100 to about 300 Angstroms. [0041] In a preferred embodiment, the third layer is between the first layer and the second layer. In another preferred embodiment, the second layer is adjacent to the third layer, the first layer is adjacent to the third layer. In yet another preferred embodiment, the third layer is between the first layer and the fourth layer. In another preferred embodiment, the fourth layer is adjacent to the third layer, the first layer is adjacent to the third layer. In yet another preferred embodiment, the third layer is between the first layer and the second layer, and an additional layer is between the first layer and the fourth layer. In yet another preferred embodiment, the fifth layer is adjacent to the fourth layer. [0042] In a preferred embodiment, this disclosure relates to a film comprising: (a) a second layer having thermoplastic, the thermoplastic comprising at least one of polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-propylene- butylene terpolymer, and propylene-butylene copolymer, the second layer has a thickness in the range of about 0.50 to 2.0 micron, the second layer having a cavitating agent;

(b) a first layer comprising polypropylene with cavitating agent, the first layer having a thickness in the range of about 15 to 80 microns;

(c) optionally a third layer comprising a polyolefm having at least one of polypropylene, polypropylene with cavitating agent, and the polyolefm is grafted with a functional group, the third layer having a thickness in the range of about

0.5 to 15 microns;

(d) optionally a fourth layer comprising at least one of polylactic acid, ethylene vinyl alcohol polymer, or high density polyethylene, the fourth layer having a thickness in the range of about 0.5 to 2 microns, the third layer is between the first layer and the fourth layer, the fourth layer is adjacent to the third layer, the first layer is adjacent to the third layer; and

(e) optionally a fifth layer adjacent to the fourth layer, the fifth layer comprising metal and having a thickness in the range of about 100 to about 300 Angstroms.

[0043] In some embodiments, this disclosure relates to a process of making the film of the present disclosure, the process comprises steps of: a) co-extruding: i) the first layer; ii) at least one of the second layer, the third layer, and the fourth layer; and b) orienting the co-extruded film in at least one direction.

[0044] In some embodiments, the process of this disclosure is free of laminating step. In other embodiment, the process further comprising a vacuum metal depositing step. [0045] In a preferred embodiment, the film of this disclosure is made by currently commercial oriented polypropylene film manufacturing steps comprising extrusion casting, machine direction (MD) and/or transverse direction (TD) stretching, winding and recovering a film comprising:

(a) a first layer comprising at least one of polypropylene, polypropylene with cavitating agent, and mono-oriented high density polyethylene; the first layer has a density in the range of 0.2 to 0.96 gm/ cm³ and a thickness in the range of about 0.5 to 80 microns; and

(b) optionally at least one of a second layer having thermoplastic, the thermoplastic comprises at least one of polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-propylene -butylene terpolymer, propylene-butylene copolymer and the second layer has a thickness in the range of about 0.50 to 2.0 micron thickness, a third layer, the third layer comprising a polyolefm having at least one of polypropylene, polypropylene with cavitating agent, and the polyolefm is grafted with a functional group, the third layer has a thickness in the range of about 0.5 to 8 microns, a fourth layer comprising at least one of polylactic acid, ethylene vinyl alcohol polymer, or high density polyethylene, the fourth layer has a thickness in the range of about 0.5 to 2 microns, wherein the film has an impact strength equal to or less than 0.236 cm*kg_f/μm. [0046] In some embodiments, this disclosure relates to a package structure comprising a container, a film lidding material comprising the film of this disclosure, and a sealant or adhesive between the container and the film lidding material, the container comprising at least one of polyvinylchloride, polyamide, polyolefm, polyethylene terephthalate, the sealant or adhesive comprising at least one of polyethylene, ethylene-propylene copolymer, ethylene- propylene-butylene terpolymer, propylene-butylene copolymer, and EVA, EAA, ionomer (Surlyn^®), LDPE, LLDPE. First Layer

[0047] The first layer of a film, especially a multilayered film, is commonly the thickest layer and provides the foundation of the film. The first layer may comprise at least one of polypropylene, polypropylene with cavitating agent, and high density polyethylene ("HDPE").

[0048] In some embodiments, the first layer consists essentially of polypropylene and the first layer has a thickness in the range of about 0.5 to 80 microns. In other embodiments, the first layer consists essentially of polypropylene with cavitating agent and the first layer has a thickness in the range of about 15 to 80 microns. In yet other embodiments, the first layer consists essentially of mono-oriented high density polyethylene, the first layer has a thickness in the range of about 0.5 to 20 microns.

[0049] The first layer may further comprise one or more additives. Preferred additives for the first layer include, but are not limited to, hydrocarbon resin(s), hydrocarbon wax(es), opacifying or coloring agent(s), slip additive(s), and cavitating agent(s). Second Layer

[0050] A second layer is an optional layer and when present is generally the outermost layer of the multilayer film. In a preferred embodiment, the second layer is a skin layer. The second layer may be contiguous to the first layer , or alternatively may be contiguous to one or more other layers, such as, the third layer.

[0051] The second layer may be provided to improve the film's barrier properties, processability, printability, and compatibility for metallization, and coating. For example, the second layer may comprise a polymer that provides a printable or metallizable layer or that enhances processability of the film. [0052] The second skin layer may comprise thermoplastic, the thermoplastic comprising at least one of polyethylene, polypropylene, ethylene -propylene copolymer, ethylene - propylene-butylene terpolymer, and propylene-butylene copolymer. The second layer has a thickness in the range of about 0.5 to 2.0 micron. [0053] The thickness of the second skin layer depends upon the intended function of the layer, but is usually in the range of 0.5 μm to 2 μm, or 0.6 μm to 1.5 μm, or 0.5 μm to 1 μm. [0054] The second layer may further comprise additives such as, for example, anti-block agents, anti-static agents, slip agents, cavitating agent, and combinations thereof. Third Layer [0055] The third layer of a multilayer film is typically used to connect two other, partially or fully incompatible, layers of the multilayer film structure, e.g., a first layer and a second layer, and is positioned intermediate these other layers. In some embodiments, the third layer is in direct contact, i.e., contiguous, with the surface of the first layer . In other embodiments, another layer or layers may be intermediate the first layer and the third layer. [0056] In some embodiments, the multilayer film comprises an optional additional layer. The additional layer is generally located on the side of the first layer opposite of the third layer.

[0057] The third layer and/or the additional layer may comprise a polyolefm having at least one of polypropylene and polypropylene with cavitating agent, optionally the polyolefin is grafted with a functional group. In a preferred embodiment, the functional group is maleic anhydride.

[0058] The thickness of the third layer and/or additional layer may be in the range of about 0.5 μm to 15 μm, or 1 μm to 12 μm, or preferably about 2 μm to 10 μm. In other embodiments, the thickness of the third layer and/or additional layer may be in the range of 0.5 μm to 8 μm, or 1 μm to 6 μm, or 1 μm to 4 μm. [0059] The third layer and/or additional layer may further comprise one or more additives such as, for example, opacifying agents, pigments colorants, cavitating agents, slip agents, antioxidants, anti-fog agents, anti-static agents, anti-block agents, fillers, moisture barrier additives, gas barrier additives, and combinations thereof. Fourth Layer

[0060] The fourth layer is generally one of the outermost layers of the multilayer film and may be used to form a seal or a barrier. The seal may be heat-sealable, pressure-sealable, or may include a sealing agent such as an adhesive. While the term "sealant skin" is used to describe this layer, an adhesive is not required. In a preferred embodiment the fourth layer is contiguous to the third layer. In other embodiments, one or more other layers may be intermediate the third layer and the fourth layer. Generally, the fourth layer is on the same side of the first layer as the third layer.

[0061] Preferably, the sealant skin layer comprises at least one of polylactic acid, ethylene vinyl alcohol polymer, or high density polyethylene. [0062] The thickness of the fourth layer is typically in the range of about 0.5 μm to 2 μm, or 0.6 μm to 1.5 μm, or 0.5 μm to 1 μm.

[0063] The fourth layer may further comprise additives, such as, for example, anti-block agents, anti-static agents, slip agents, and combinations thereof. Orientation [0064] The film may be uniaxially or biaxially oriented. Orientation in the direction of extrusion is known as machine direction ("MD") orientation. Orientation perpendicular to the direction of extrusion is known as transverse direction ("TD") orientation. Orientation may be accomplished by stretching or pulling a film first in the MD followed by the TD. Orientation may be sequential or simultaneous, depending upon the desired film features. Preferred orientation ratios are commonly from between about three to about six times in the MD and between about four to about ten times in the TD.

[0065] Blown films may be oriented by controlling parameters such as take up and blow up ratio. Cast films may be oriented in the MD direction by take up speed, and in the TD through use of tenter equipment. Blown films or cast films may also be oriented by tenter- frame orientation subsequent to the film extrusion process, in one or both directions. Typical commercial orientation processes are BOPP tenter process and LISIM technology. Surface Treatment

[0066] One or both of the outer exposed surfaces of the film may be surface-treated to increase the surface energy of the film to render the film receptive to metallization, coatings, printing inks, and/or lamination. The surface treatment can be carried out according to one or several of the methods known in the art. Preferred methods include, but are not limited to, corona discharge, flame treatment, plasma treatment, chemical treatment, or treatment by means of a polarized flame. [0067] In a preferred embodiment, the outermost surface of the film, e.g., the outermost surface of the second layer is surface treated. Thus, in a preferred embodiment the fourth layer is not surface treated. Metallization [0068] One or both of the outer exterior surfaces of the film may be metallized. Generally, the metallized layer or the fifth layer is on the surface of one of the second and/or fourth layers. However, if no second or fourth layer is present, the surface of a first layer may be metallized. Such layers may be metallized using conventional methods, such as vacuum deposition of a metal layer such as aluminum, copper, silver, chromium, or mixtures thereof. In a preferred embodiment, the fifth layer metal is aluminum. In another preferred embodiment, the aluminum fifth layer has a thickness in the range of about 100 to about 300 Angstroms.

[0069] Metallization is generally applied to which ever outermost surface of the film that has been treated. Metallization or coatings may be applied alone or in some cases together. When metallization and coatings are applied together, either may be applied first, followed by the other. In some embodiments, the film may first be treated, for example by flame treatment, and then be treated again in the metallization chamber, for example by plasma treatment, immediately prior to being metallized. Coatings [0070] One or more coatings, such as for barrier, printing, and/or processing, may be applied to one or both of the outer surfaces of the films. Such coatings may include acrylic polymers, such as ethylene acrylic acid ("EAA"), ethylene methyl acrylate copolymers ("EMA"), polyvinylidene chloride ("PVdC"), poly(vinyl)alcohol ("PVOH"), ethylene(vinyl)alcohol ("EVOH"), and combinations thereof. [0071] Before applying the coating composition to the appropriate surface, the outer surface of the film may be treated to increase its surface energy. This treatment may help to ensure that the coating layer will be strongly adhered to the outer surface of the film, and thus reduce the possibility of the coating peeling or being stripped from the film. This treatment can be accomplished by employing known techniques, such as flame treatment, plasma, corona discharge, film chlorination, treatment with oxidizing agents such as chromic acid, hot air or steam treatment, and the like. A preferred method is corona discharge where the film surface is exposed to a high voltage corona discharge while passing the film between a pair of spaced electrodes. After surface treatment, the coating composition may then be applied thereto. [0072] An intermediate primer coating may be applied to the film. This is particularly useful in applications where a greater coating-to-film adherence is desired than that resulting from surface treatment of the film. Before applying the primer the film may first be treated to provide increased active adhesion sites on the film's surface (thereby promoting primer adhesion). Then a continuous coating of a primer material may be applied to the surface treated film surface. Examples of useful primer materials are well known in the art and include, but are not limited to, epoxy and poly(ethylene imine) materials. The primer provides an overall adhesively active surface for thorough and secure bonding with the subsequently applied coating composition. The primer may be applied to the film by conventional solution methods, for example, by roller application. [0073] The coatings are preferably applied by an emulsion coating technique, but may also be applied by co-extrusion. The coating composition may be applied to the film as a solution or in any other conventional manner, such as by gravure coating, roll coating, dipping, spraying, and the like. Any excess aqueous solution can be removed by squeeze rolls, doctor knives, and the like. [0074] The film can be stretched in the MD, coated with the coating composition and then stretched perpendicularly in the TD. In another embodiment, the coating can be carried out after biaxial orientation is complete.

[0075] The coating composition may be applied in such as amount so that there will be deposited upon drying a smooth, evenly distributed layer. The coating may be dried by hot air, radiant heat, or by any other conventional means. Generally, the coating composition is on the order of 0.2 μm to 5 μm in thickness, or in the range of 0.3 Ig to 5.43g of coating per square meter of film. Useful coatings may have coating weights in the range of 0.5 g/m to 1.6 g/m² for conventional PVOH coatings, 0.78 g/m² to 2.33 g/m² for conventional acrylic and low temperature seal coatings, and 1.6 g/m² to 6.2 g/m² for conventional PVdC coatings. Additives

[0076] One or more layers of the film may further contain one or more additives. Examples of useful additives include, but are not limited to, opacifying agents, pigments, colorants, cavitating agents, slip agents, antioxidants, anti-fog agents, anti-static agents, anti- block agents, moisture barrier additives, gas barrier additives, hydrocarbon resins, hydrocarbon waxes, fillers such as calcium carbonate, diatomaceous earth and carbon black, and combinations thereof. Such additives may be used in effective amounts, which vary depending upon the property required.

[0077] Examples of suitable opacifying agents, pigments, or colorants include, but are not limited to, iron oxide, carbon black, aluminum, titanium dioxide, calcium carbonate, talc, and combinations thereof.

[0078] In some aspects, the cavitating agent comprises at least one of polybutylene terephthalate, cyclic olefin copolymers, glass spheres, precipitated calcium carbonate, calcium-magnesium carbonates, dolomite, silicates, barium sulphate, carbon black, slate powder, pearl white, silica, hydrated alumina, kaolin, diatomite, mica, and talcum, the cavitating agent having a particle size of from about 0.5 to about 15 microns. In a preferred embodiment, the first layer has a cavitating agent concentration in the range of 10 to 70 wt.%. [0079] Cavitating agents or void-initiating particles may be added to one or more layers of the film to create an opaque film. Preferably, the cavitating agents or void-initiating particles are added to the first layer. In some embodiments, the cavitating agents or void- initiating particles are added to the third layer. Generally, the cavitating or void-initiating additive includes any suitable organic or inorganic material that is incompatible with the polymer material(s) contained in the layer(s) to which the cavitating or void-initiating additive is added, at the temperature of biaxial orientation. Examples of suitable void- initiating particles include, but are not limited to, polybutylene teraphthalate ("PBT"), nylon, cyclic-olefm copolymers, solid or hollow pre-formed glass spheres, metal beads or spheres, ceramic spheres, precipitated calcium carbonate, calcium-magnesium carbonates, dolomite, silicates, barium sulphate, carbon black, slate powder, pearl white, silica, hydrated alumina, kaolin, diatomite, mica, and talcum, talc, chalk, or combinations thereof. The average diameter of the void-initiating particles is typically in the range of about 0.1 μm to 15 μm. The particles may be of any desired shape, or preferably they are substantially spherical in shape. This does not mean that every void is the same size. It means that generally each void tends to be of like shape when like particles are used even though they vary in dimensions. These voids may assume a shape defined by two opposed and edge contacting concave disks. [0080] In some embodiments, the cavitating agent has a concentration in the range of 10 to 70 wt.%. In some preferred embodiment, the cavitating agent has a concentration in the range of 10 to 70 wt.% for the first layer and/or the third layer . The amount of the cavitating agent in the first layer and/or the third layer is sufficient to obtain the desired Impact Strength of the films of this disclosure.

[0081] The amount of the cavitating agent in the first layer and/or the third layer in the film of this disclosure is in the range of 10 to 70 wt.%. The following concentration values are useful lower concentration limits: 10, 20, 30, 40, 50, 60, and 65 wt.%. The following concentration values are useful upper concentration limits: 20, 30, 40, 50, 60, and 70 wt.%. The concentration for the use of the present film as blister pack lidding material falls in a range between any one of the above-mentioned lower concentration limits and any one of the above-mentioned upper concentration limits, so long as the lower concentration limit is less than or equal to the upper concentration limit.

[0082] Alternatively, one or more layers of the film may be cavitated by beta nucleation, which includes creating beta-form crystals of polypropylene and converting at least some of the beta-crystals to alpha-form polypropylene crystals thus leaving small voids remaining after the conversion. Preferred beta-cavitated embodiments also comprise a beta-crystalline nucleating agent. Substantially any beta-crystalline nucleating agent ("beta nucleating agent" or "beta nucleator") may be used.

[0083] Slip agents that may be used include, but are not limited to, higher aliphatic acid amides, such as fatty amide; higher aliphatic acid esters; waxes; silicone oils; silicone gum; and metal soaps. Such slip agents may be used in amounts in the range of 0.1 wt% to 2 wt% based on the total weight of the layer to which it is added. An example of a fatty acid slip additive that may be used is erucamide. In one embodiment, a conventional polydialkylsiloxane, such as silicone oil or silicone gum, additive having a viscosity of 10,000 to 2,000,000 cSt is used. [0084] In some embodiments, the second layer of the film of this disclosure comprises at least one of antiblock additives and/or at least one of non-migratory slip agent. The anti- block agent being present is in the range of about 500 to about 30,000 ppm by weight. [0085] Useful antiblock additives include, but are not limited to, silica-based products such as inorganic particulates such as silicon dioxide, calcium carbonate, magnesium silicate, aluminum silicate, calcium phosphate, and the like. In some embodiments, non-migratory slip agents may be used as the antiblock additive in one or more of the outer surface layers of the film or in one or more of the third layers. Non-migratory means that these agents do not generally change location throughout the layers of the film in the manner of migratory slip agents. A preferred non-migratory slip agent is polymethyl methacrylate ("PMMA"). The non-migratory slip agent may have a mean particle size in the range of 0.5 μm to 15 μm, or 0.5 μm to 13 μm, or 1 μm to 10 μm, or 1 μm to 5 μm, or 2 μm to 4 μm, depending on the layer's thickness and desired slip properties. In some embodiments, the size of the particles in the non-migratory slip agent may be greater than 10% of the thickness of the surface layer containing the slip agent, or greater than 20% of the layer's thickness, or greater than 40% of the layer's thickness, or greater than 50% of the layer's thickness, or greater 100% of the layer's thickness. Generally spherical, particulate non-migratory slip agents are contemplated. A commercially available example of a PMMA resins is EPOSTAR™ which is available from Nippon Shokubai Co., Ltd. of Japan. Other useful antiblock additives include polysiloxanes and non-meltable crosslinked silicone resin powder, such as TOSPEARL™, which is commercially available from Toshiba Silicone Co., Ltd. Antiblocking agents may be effective in amounts up to about 30,000 ppm by weight of the layer to which it is added.

[0086] An example of a suitable antioxidant includes phenolic anti-oxidants, such as IRGANOX™ 1010, which is commercially available from Ciba-Geigy Company of Switzerland. Such an antioxidant may be used in an amount in the range of 0.1 wt% to 2 wt%, based on the total weight of the layer to which it is added.

[0087] Anti-static agents that may be used include alkali metal sulfonates, polyether- modified polydiorganosiloxanes, polyalkylpheylsiloxanes, tertiary amines, glycerol mono- sterate, blends of glycerol mono-sterate and tertiary amines, and combinations thereof. Such anti-static agents may be used in amounts in the range of about 0.05 wt% to 3 wt%, based on the total weight of the layer to which the anti-static is added. An example of a suitable antistatic agent is ARMOSTAT™ 475, commercially available from Akzo Nobel. [0088] Examples of useful fillers include but are not limited to, finely divided inorganic solid materials such as silica, fumed silica, diatomaceous earth, calcium carbonate, calcium silicate, aluminum silicate, kaolin, talc, bentonite, clay, and pulp.

[0089] Suitable moisture and gas barrier additives may include effective amounts of low- molecular weight resins, hydrocarbon resins, particularly petroleum resins, styrene resins, cyclopentadiene resins, and terpene resins. [0090] The film may further contain one or more hydrocarbon resins ("HCR") in one or more layers. In a preferred embodiment, the first layer comprises one or more HCR. The HCR may serve to enhance or modify the flexural modulus, improve processability, or improve barrier properties of the film. Preferably the HCR is a low-molecular weight hydrocarbon that is compatible with the polymers contained in the layer to which the HCR has been added. Optionally, the HCR may be hydrogenated. Suitable HCRs include, but are not limited to, petroleum resins, terpene resins, styrene resins, and cyclopentadiene resins. The HCR may have a number average molecular weight less than 5000 g/mole, preferably less than 2000 g/mole, and most preferably in the range of about 500 g/mole to about 1000 g/mole. The HCR may be natural or synthetic. In one embodiment, the HCR has a softening point in the range of 6O⁰C to 18O⁰C.

[0091] The film may also contain a hydrocarbon wax in one or more layers. In a preferred embodiment, the first layer comprises a hydrocarbon wax. The hydrocarbon wax may be either a mineral wax or a synthetic wax. Polyethylene type wax may have an average chain length of 22 to 65 carbon atoms, or 22 to 40 carbon atoms; a molecular weight in the range of 300 to 800 g/mole; and a melting point in the range of 52 ⁰C to about 88 ⁰C. Hydrocarbon waxes may include paraffin waxes and microcrystalline waxes. Preferred paraffin waxes typically include a mixture of normal and branched paraffins, with the normal paraffin content generally in the range of 35 wt% to 90 wt%. Typically, paraffin waxes having a broad molecular weight distribution are preferred as they generally provided better barrier properties than paraffin waxes with a narrow molecular weight distribution.

[0092] Optionally, one or more of the outer surface layers may be compounded with a wax or coated with a wax-containing coating, for lubricity, in amounts in the range of 2 wt% to 15 wt% based on the total weight of the layer. Process of making the films of this disclosure [0093] The films may be useful as substantially stand-alone film webs or they may be coated and/or metallized to other film structures. Films according to the present disclosure may be prepared by any suitable means. Preferably, the film is co-extruded, oriented, and then prepared for its intended use such as by coating, printing, slitting, or other converting methods. Preferred methods comprise co-extruding, then casting and orienting the film. [0094] In one embodiment, the film may be formed by co-extruding the first layer , the third layer, and the fourth layer together with any additional layers through a flat sheet extruder die at a temperature in the range of 200⁰C to 260⁰C, casting the film onto a cooling drum and quenching the film. The sheet is then stretched 3 to 7 times its original size, in the machine direction (MD), followed by stretching 5 to 10 times its original size in the transverse direction (TD). The film is then wound onto a reel. Optionally, one or both of the external surfaces may be coated and/or flame treated or corona treated before winding. Industrial Application

[0095] In one embodiment, the film of this disclosure may be used in a package structure comprising a container, a sealant or adhesive between the container and the film of the present disclosure as lidding material is contemplated. The container is compπsed of a plastic such as, for example, polyvinylchloride, polyamide, polyolefm such as, for example, polypropylene, polyethylene terephthalate or combinations thereof, and may have one or more recesses molded therein to contain packaged articles such as, for example, solid objects such as chewing gum or candy, shaped solid preparations or pharmaceutical products such as tablets or pills. If one single item, e.g., a tablet, is to be removed from the blister pack of the present disclosure the bottom part is pressed and the item pushed through the covering layer acting as a lid over the recess. The container recesses may be described as a base portion, upwardly extending side walls, flange edges extending from the side walls and an open top covered by the lidding film, and wherein the lidding film is bonded to the flange edges and extends over the open top of the recess.

[0096] The film lidding material will beneficially comprise the film of the present disclosure. The container and lidding material will be chosen to provide the "peel-and-push" or "push-through" utility of the package structure. [0097] The present disclosure will be explained in more detail referring to Examples below without intention of restncting the scope of the present disclosure. EXAMPLES Polymer Materials and Testing methods

[0098] A listing of the various components used in the multi-layer films of the examples is in the following table

Various Com onents in the Multi-La er Films

[0099] All films in Examples 1-2 were coextruded and biaxially oriented. The films in Examples 1-5 were melting coextruded, quenched on a casting drum and subsequently reheated in the machine direction orientor to about 85⁰C to about 105⁰C. All films in Examples 1-2 were then stretched in the MD at 4.8 times and further annealed, in the annealing section of the machine direction orientor. The MD stretched films were subjected to further transverse direction orientation via conventional tenter frame at 8.2 times in the TD. The typical transverse direction preheat temperature is about 155°C to about 180⁰C, stretching temperature is about 145⁰C to about 165⁰C, and standard annealing temperature is about 165°C to 17O⁰C. Example 1

[00100] This film was made by co-extruding polypropylene, ethylene -propylene copolymer with structure, composition, and materials listed in the following table. The film has poly gauge of 42 μm and optical gauge of 91 μm. The yield is 23.1 m²/kg.

Example 2

[00101] This film was made by co-extruding polypropylene, ethylene -propylene copolymer with structure, composition, and materials listed in the following table. The film has poly Gauge of 25 μm and optical Gauge of 66 μm. The yield is 38.5 m²/kg.

Test results

[00102] The films of examples 1-2 were tested for Peel Skin Adhesion, TLMI Interfacial Adhesion, Z Tear Skin Adhesion, and impact strength (or Ballburst) performance. All results are listed in the following tables. Peel Skin Adhesion Data

TLMI Interfacial Adhesion Data

Z Tear Skin Adhesion Data

Impact Strength (Ballburst) Data

[00103] The data in above table shows how the "Push Through" force (Ballburst) was cut in half by making a highly cavitated structure (Example 2).

[00104] The films of Examples 1 through 2 are tested for Tear Strength, Oxygen Transmission (OTR) and Water Vapor Transmission (WVTR) by the methods described above and the results are as indicated in the following table:

[00105] All patents, patent applications, test procedures, priority documents, articles, publications, manuals, and other documents cited herein are fully incorporated by reference to the extent such disclosure is not inconsistent with this disclosure and for all jurisdictions in which such incorporation is permitted. [00106] When numerical lower limits and numerical upper limits are listed herein, ranges from any lower limit to any upper limit are contemplated.

[00107] While the illustrative embodiments of the disclosure have been described with particularity, it will be understood that various other modifications will be apparent to and may be readily made by those skilled in the art without departing from the spirit and scope of the disclosure. Accordingly, it is not intended that the scope of the claims hereof be limited to the examples and descriptions set fourth herein but rather that the claims be construed as encompassing all the features of patentable novelty which reside in the present disclosure, including all features which would be treated as equivalents thereof by those skilled in the art to which the disclosure pertains.

Claims

CLAIMSWhat is claimed is:

1. A film comprising: a first layer comprising at least one of polypropylene, polypropylene with cavitating agent, and mono-oriented high density polyethylene; said first layer has a density in the range of 0.2 to 0.96 gm/ cm and a thickness in the range of about 0.5 to 80 microns, wherein said film has an impact strength equal to or less than 0.236 cm*kg_f/μm.

2. The film of claim 1 , said first layer consisting essentially of polypropylene, said first layer has a thickness in the range of about 0.5 to 10 microns.

3. The film of claim 1, said first layer consisting essentially of polypropylene with cavitating agent, said first layer has a thickness in the range of about 15 to 80 microns.

4. The film of claim 1, said first layer consisting essentially of mono-oriented high density polyethylene, said first layer has a thickness in the range of about 0.5 to 20 microns.

5. The film of any preceding claim further comprising a second layer having thermoplastic, said thermoplastic comprises at least one of polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-propylene-butylene terpolymer, propylene-butylene copolymer and said second layer has a thickness in the range of about 0.50 to 2.0 micron.

6. The film of any preceding claim further comprising a third layer, said third layer comprising a polyolefin having at least one of polypropylene, polypropylene with cavitating agent, and optionally said polyolefin is grafted with a functional group, said third layer has a thickness in the range of about 0.5 to 8 microns.

7. The film of claim 6 wherein said third layer is between the first layer and the second layer.

8. The film of any preceding claim, wherein said cavitating agent of the first layer or third layer comprises at least one of polybutylene terephthalate, cyclic olefin copolymers, glass spheres, precipitated calcium carbonate, calcium-magnesium carbonates, dolomite, silicates, barium sulphate, carbon black, slate powder, pearl white, silica, hydrated alumina, kaolin, diatomite, mica, and talcum, said cavitating agent having a particle size of from about 0.5 to about 15 microns.

9. The film of any preceding claim further comprising a fourth layer comprising at least one of polylactic acid, ethylene vinyl alcohol polymer, or high density polyethylene, said fourth layer has a thickness in the range of about 0.5 to 2 microns.

10. The film of claim 9 wherein said third layer is between the first layer and the fourth layer, said fourth layer is adjacent to the third layer, said first layer is adjacent to the third layer.

11. The film of any preceding claim further comprising a fifth layer having metal, said fifth layer has a thickness in the range of about 100 to about 300 Angstroms.

12. The film of claim 11, wherein said fifth layer is adjacent to the fourth layer.

13. The film of claim 1 1 wherein said fourth layer is treated on the side adjacent to the fifth layer with at least one of corona discharge, flame treatment, plasma treatment, chemical treatment, or treatment by means of a polarized flame.

14. The film of any preceding claim wherein said polyolefm is grafted with a functional group.

15. The film of any preceding claim having properties including tear strength of from about 200 to about 500 grams; oxygen transmission rate of from about 0 to about 2.1 cm³c/m²/24 hours at 23°C and 0% relative humidity; water transmission rate of less than about 1 g/m²/24 hours at 38°C and 90% relative humidity; elongation

(inelasticity) of less than about 200%; and light barrier (light transmission rate) of from about 0.4 to about 1.1 %.

16. The film of any one of claims 5-15 wherein said second layer comprises at least one of ethylene -propylene copolymer or ethylene -propylene-butylene terpolymer.

17. The film of any one of claims 5-16, wherein said first layer and at least one of said second layer, said third layer, said fourth layer and said fifth layer are co-extruded to form said film.

18. The film of any preceding claim, wherein said film is axially oriented.

19. The film of any preceding claim, wherein said film is monoaxially oriented.

20. The film of any one of claims 1-19, wherein said film is biaxially oriented.

21. A film comprising : a. a second layer having thermoplastic, said thermoplastic comprising at least one of polyethylene, polypropylene, ethylene-propylene copolymer, ethylene- propylene-butylene terpolymer, and propylene-butylene copolymer, said second layer has a thickness in the range of about 0.50 to 2.0 micron, said second layer having a cavitating agent; b. a first layer comprising polypropylene with cavitating agent, said first layer having a thickness in the range of about 15 to 80 microns; c. optionally a third layer comprising a polyolefϊn having at least one of polypropylene and polypropylene with cavitating agent, optionally said polyolefm is grafted with a functional group, said third layer having a thickness in the range of about 0.5 to 15 microns; d. optionally a fourth layer comprising at least one of polylactic acid, ethylene vinyl alcohol polymer, or high density polyethylene, said fourth layer having a thickness in the range of about 0.5 to 2 microns, said third layer is between the first layer and the fourth layer, said fourth layer is adjacent to the third layer, said first layer is adjacent to the third layer; and e. optionally a fifth layer adjacent to the fourth layer, said fifth layer comprising metal and having a thickness in the range of about 100 to about 300 Angstroms.

22. A process of making the film of any one of claims 5-21 comprising the steps of: a) co-extruding: i) said first layer; ii) at least one of said second layer, said third layer, and said fourth layer; and b) orienting the co-extruded film in at least one direction.

23. The process of claim 22 is free of laminating step.

24. The process of claim 22 or 23 further comprising a vacuum metal depositing step.

25. A package structure comprising a container, a film lidding material comprising the film of any one of claims 1-20, and a sealant or adhesive between said container and said film lidding material, said container comprising at least one of polyvinylchloride, polyamide, polyethylene terephthalate and expand the list of container materials, said sealant or adhesive comprising at least one of polyethylene, ethylene-propylene copolymer, ethylene-propylene-butylene terpolymer, propylene-butylene copolymer, and expand the list of adhesive materials (EVA, EAA, ionomer (Surlyn®), LDPE, LLDPE, etc.).