MX2007011951A - Polyvinylidene chloride layered silicate nanocomposite and film made therefrom - Google Patents

Abstract

A polymeric film includes at least one layer, the at least one layer including a polyvinylidene chloride layered silicate nanocomposite composition, the composition in¬cluding 100 parts, by weight of the composition, of a polyvinylidene chloride layered sili- cate nanocomposite;from 0.1 to 10 parts, by weight of the composition, of a stabilizer;and from 0.1 to 10 parts, by weight of the composition, of a polymeric processing aid. Alternatively, a polymeric film includes at least one layer, the at least one layer including a polyvinylidene chloride layered silicate nanocomposite composition, the composition including 100 parts, by weight of the composition, of a polyvinylidene chloride layered silicate nanocomposite;and from 0.1 to 10 parts, by weight of the composition, of a soap of a fatty acid. A blister pack can be made from either film.

Description

NANOCOMPOSIT OF SILICATE IN POLYVINYLIDENUM AND FILM CHLORIDE LAYERS DONE FROM THE SAME This application claims the benefit of the US Provisional Application Serial No. 60/666213, filed on March 29, 2005, the contents of which is incorporated in the present by reference. Field of the Invention The present invention relates to a silicate nanocomposite in layers of polyvinylidene chloride, and a composition and film made therefrom, such as a film suitable for the packaging of pharmaceutical products in blister packs. BACKGROUND OF THE INVENTION Conventional blister packs typically include a base with one or, more commonly, a plurality of recesses that are surrounded by a shoulder, and a lid attached to the shoulder. Tablets, capsules, or other contents are accommodated in respective recesses, and they can be separated (1) by pressing in the respective recess, thus making the content penetrate the lid (usually a thin aluminum or similar), or (2) Removing the portion of the lid that remains on the recess, thus having access to the contents of the recess. In practice, a base is formed with recesses, and with a shoulder that4 defines the base material between the recesses; the recesses of the base are filled with tablets, etc .; the base, with the recesses full, is covered with a lid; and the lid is sealed or otherwise adhered to the base shoulder. The base of the blister pack is sometimes made of an inner portion (which will adhere to the cap) of ACLARMR PTFE (polychlorotrifluoroethylene), a material that is very expensive, and with less than optimal oxygen barrier properties. This material shows a moisture vapor transmission rate (MVTR) typically of about 0.4 grams / m 'for one thousandth of a thickness. The outer portion of the base is often a PVC (polyvinyl chloride) of about 250 micrometers (10 mils) thick. PVC, polyamides, polyolefins, polyesters are other materials that can be used to make the base. A thin sheet of aluminum can be added to the base. The cap is typically made of thin aluminum foil or a thin foil laminate of aluminum. The thin foil of aluminum is a preferred material for the blister pack legs since the thickness of the material used requires relatively little force to break. As a result, the energy for penetration is low and aluminum does not essentially exhibit elasticity. Plastic laminates can also be used for the lid. Some blister packs have a lid provided with a line of weakness in the region of each recess. In others, each recess may be covered with an individual lid segment. Within the line of weakness or in each lid segment there may be a clamping tab that allows the individual recess to be exposed by removing the lid segment. The provision of a vinylidene chloride copolymer, often referred to as "saran" or "PVdC", in a PVdC composition capable of providing a packing film with a low moisture vapor transmission rate (MVTR), and also a Under Oxygen Transmission Regime (OTR), it would be desirable for applications such as the packaging of the pharmaceutical products sensitive to both, oxygen and moisture. Stabilizers are often used when formulating compositions based on PVdC. These stabilizers reduce the thermal degradation of PVdC formulations during extrusion. Unfortunately, an exchange in OTR and thermal stability can sometimes be done when designing such formulations. Thus, a composition having increased amounts of a stabilizer will sometimes result in improved thermal stability, but at the expense of oxygen barrier properties. Conversely, improved (lower) OTR can be obtained by reducing the relative amounts of stabilizer in the formulation, but this may result in a less stable PVdC composition. U.S. Patent No. 6,673,406 (Bekele), incorporated herein by reference in its entirety, discloses a composition and film wherein a hydrophilic clay such as modified monomorillonite is mixed with a PVdC, and the mixture is incorporated into a film. polymer that has at least one layer. Nanosilicates are available in natural (clay) or synthetic grades. It has been found that natural grades tend to disperse low when mixed in volume in PVdC. Due to this low dispersity, the oxygen barrier property of a film made of a PVdC / natural nanosilicate blend will not necessarily be improved. Modified grades of nanosilicates have better dispersion characteristics than natural grades, and therefore, generally better oxygen barrier. However, the surface treatments used to modify nanosilicates are based on quaternary alkyl ammonium chloride. Regardless of the alkyl component of this salt, it has been found that this material adversely affects the thermal stability of the PVdC to which it is mixed. It has also been found that there are load limitations with respect to both natural and modified nanosilicate grades when an extrusion coating process is used. Extrusion coating is a well-known process for making shrinkable bags containing PVdC. In general, in an extrusion coating process, less than 4% by weight of the PVdC mixture can be made from the nanosilicates. Therefore, it is desirable to direct the dispersion capacity, thermal stability and load issues raised by volume mixing of nanosilicates in PVdC. SUMMARY OF THE INVENTION In a first aspect, a composition comprises a silicate nanocomposite in layers of polyvinylidene chloride. In a second aspect, a polymeric film comprises at least one layer, the at least one layer comprising a silicate nanocomposite in layers of polyvinylidene chloride. In a third aspect, a polymer film comprises at least one layer, the at least one layer comprising a silicate nanocomposite composition in p-livinylidene chloride layers, the composition comprising 100 parts, by weight of the composition, of a nanocomposite of silicate in layers of polyvinylidene chloride; from 0.1 to 10 parts, by weight of the composition, of a stabilizer; and from 0.1 to 10 parts, by weight of the composition, of a polymeric processing aid. In a fourth aspect, a polymer film comprises at least one layer, the at least one layer comprising a silicate nanocomposite composition in layers of polyvinylidene chloride, the composition comprising 100 parts, by weight of the composition, of a silicate nanocomposite. in layers of polyvinylidene chloride; and from 0.1 to 10 parts, by weight of the composition, of a soap of a fatty acid. In a fifth aspect, a blister pack comprises a base, the base comprising a plurality of recesses, and a shoulder surrounding the recesses; a lid fixed to the shoulder; and contents arranged in respective recesses, wherein at least one of the base and cap comprises a silicate nanocomposite composition in layers of polyvinylidene chloride, the composition comprising 100 parts, by weight of the composition, of a layered silicate nanocomposite. of polyvinylidene chloride; from 0.1 to 10 parts, by weight of the composition, of a stabilizer; and from 0.1 to 10 parts, by weight of the composition of a polymeric processing aid. In a sixth aspect, a blister pack comprises a base, the base comprising a plurality of recesses, and a shoulder surrounding the recesses; a lid fixed to the shoulder; and contents arranged in respective recesses; wherein at least one of the base and cap comprises a silicate nanocomposite composition in layers of polyvinylidene chloride, the composition comprising 100 parts, by weight of the composition, of a silicate nanocomposite in layers of polyvinylidene chloride; and from 0.1 to 10 parts, by weight of the composition, of a soap of a fatty acid. In a seventh aspect, a silicate nanocomposite composition in layers of polyvinylidene chloride comprises 100 parts, by weight of the composition, of a silicate nanocomposite in layers of polyvinylidene chloride; from 0.1 to 10 parts, by weight of the composition, of a stabilizer; and from 0.1 to 10 parts, by weight of the composition, of a polymer processing aid. In an eighth aspect, a silicate nanocomposite composition in layers of polyvinylidene chloride comprises 100 parts, by weight of the composition, of a silicate nanocomposite in layers of polyvinylidene chloride; and from 0.1 to 10 parts, by weight of the composition, of a soap of a fatty acid. Definitions "Silicate nanocomposite in polyvinylidene chloride layers" and "silicate nanocomposite in PVdC layers" and the like herein refer to a polymer prepared in situ in a suspension process and / or an emulsion process. The in situ process allows the penetration of polymer resulting in finite expansion of the silicate crystals that produce intercalated polymer / clay hybrids. With extensive polymer penetration of exfoliation and delamination of the silicate crystallites is achieved by resulting in nanoscale silicate layers suspended in a PVdC matrix. In a method for making the polymer, a high polarity, aqueous dispersion of a nanoclay is predispersed in a pre-mixed monomer prior to polymerization. The nanoclay can be a kaolin, a talc, an ectite, a vermiculite or a mica. The pre-dispersion of the nanoclay can be as high as 10% by weight of the total monomer content of the suspension. After the pre-mix is prepared, the conventional polymerization and subsequent polymerization steps are carried out. The result is a copolymer of vinylidene chloride, having vinylidene chloride monomer and a comonomer such as vinyl chloride, styrene, villyl acetate, acylonitoplo, and Ci-Ci calcyl esters of (meth) acrylic acid (v. .gr., methylacrylate, butylacrylate, methylmethacrylate, etc.) and also including up to 10%, by weight of the composition, of a nanosilicate. "(Meth) acrylic acid" refers here to both acrylic acid and / or methacrylic acid; "(meth) acrylate" in the present refers to both acrylate and methacrylate; "polymer" refers herein to the product of a polymerization reaction, and is inclusive of homopolymers, copolymers, terpolymers, tetrapolymers, etc. "copolymer" herein refers to a polymer formed by the polymerization reaction of at least two different monomers and is inclusive of random copolymers, block copolymers, metal copolymers, etc.; "ethylene / alpha-olefin copolymer" (EAO) herein refers to copolymers of ethylene with one or more comonomers selected from alpha-olefms of C3 to Ci such as propene, butene-1, hexene-1, octene-1 , etc., wherein the molecules of the copolymers comprise long polymer chains with relatively few side chain branches that arise from the alpha-olefin which was reacted with ethylene. This molecular structure must be contrasted with conventional low pressure or medium density polyethylene which are highly branched with respect to EAOs and whose high pressure polyethylenes contain both long chain and short chain solutions. EAO includes such heterogeneous materials as medium density linear polyethylene (LMDPE), linear density polyethylene (LLDPE), and ultra high density polyethylene (VLDPE and ULDPE), such as DOWLEXMR or ATTANEMK resins SUPPLIED BY Dow, ESCORENEMR or EXCEEDMK resins SUPPLIED BY Exxon; as well as linear homogeneous ethylene / alpha-olefin copolymers (HEAO) such as TAMFERMR resins supplied by Mitsui Petrochemical Corporation, EXACTMf resins supplied by Exxon, or branched long chain AFFINITY (HEAO) resins supplied by the Dow Chemical Company, or ENGAGEK reams supplied by DuPont Dow Elastomers, "package" herein refers to a film configured around a product; "film" herein refers to plastic weave materials having a thickness of 0.50 mm (20 mils) or less such as 0.25 mm (10 mil) or less, "seal layer" herein refers to a layer of a film that can be involved in sealing the film to itself or another layer, "stamp" on the present refers to a bond of a first film surface to a second film surface created by heating (e.g., by means of a heated rod, hot air, infrared radiation, ultrasonic sealing). ca, etc.) the respective surfaces at least their respective seal start temperatures; "barrier" herein refers to a layer of a film that can significantly retard the transmission of one or more gases (e.g., O); "Abuse layer" herein refers to a layer of a film that can withstand abrasion, perforation, k and / or other potential causes of packet integrity reduction, and / or potential causes of appearance quality reduction. of package; "link layer" herein refers to a layer of a film that can provide interlayer adhesion to adjacent layers that include otherwise non-adherent or weakly adhering polymers; "volume layer" herein refers to a layer of a film that can increase the abuse resistance, hardness or modulus of a film; "lamination" herein refers to the bonding of two or more layers of film together, e.g., by the use of polyurethane adhesive; "Total free shrink" means the percent of dimensional change in a 10 cm x 10 cm film sample, when shrinking at a specified test temperature, such as 85 ° CD (185 ° F), with the quantitative determination being carried out in accordance with ASTM D 2722, as set forth in the 1990 Annual Book of ASTM Standards, vol. 08.02. 368-371, the full disclosure of which is incorporated herein by reference.

"Total free shrink" refers to the total free shrink in both the longitudinal direction and the transverse direction. "machine direction" herein refers to the direction along the length of a film, ie, in the direction of the film as it is formed during extrusion and / or coating; and "transverse direction" herein refers to the direction through a film, that is, the direction that is perpendicular to the machine direction. "Linear low density polyethylene" (LLDPE) herein refers to polyethylene having a density of 0.917 to 0.925 grams per cubic centimeter, made by Zeigler / Natta catalysis, "Medium density linear polyethylene" (LMDPE) in the present refers to polyethylene having a density of 0.926 grams per cubic centimeter at 0.939 grams per cubic centimeter, made by Zeigler / Natta catalysis. The term "orientation ratio" (ie, the product to the extent to which a film is oriented in different directions, usually two directions perpendicular to each other) is used when describing the degree of orientation of a given film. The orientation in the machine direction is referred to as "stretched", while the orientation in the transverse direction is referred to as "stretching". For films extruded through an annular die, the stretch is obtained by blowing the film to produce a bubble. For such films, the drawing is obtained by passing the film through two sets of activated grip rollers, with the downstream adjustment having a higher surface velocity than the upstream adjustment, with the resulting stretch ratio being the velocity surface of the current adjustment under gripping rollers divided by the surface speed of the upstream adjustment of gripping rollers. All composition percentages used herein are presented on a "by weight" basis, unless otherwise designated. BRIEF DESCRIPTION OF THE DRAWINGS A detailed description of embodiments of the invention follows, with reference to the accompanying drawings, in which: Figure 1 is a schematic cross section of a monolayer film; Figure 2 is a schematic cross-section of a two-layer film; Figure 3 is a schematic cross section of a three layer film; Figure 4 is a schematic cross section of a four layer film; Figure 5 shows a longitudinal section through a blister pack; Figure 6 shows a plan view of the blister pack of Figure 5; Figure 7 is a cross section through the blister pack of Figure 6; and Figure 8 shows an expanded fragmentary cross-sectional view of the blister package of Figure 6. Detailed Description of the Invention In Situ Polymerization Clays are naturally occurring minerals, and therefore their composition is highly variable. The purity of the clay will affect the final properties of the compound. Many clays are aluminosilicates that have layered structures similar to leaves and consist of silica S1O4 tetrahedrop bound to alumina AI06 octahedra in a variety of forms. A 2: 1 tetrahero to octahedron results in smectite clays. Among the smectites the most common is montmopllonite (bentonite). Other metals such as magnesium can replace aluminum in the crystal structure. These clays of magnesiosilicates are hectopta. Depending on the composition of the clay the leaves or layers carry a load on the surface at the edges. This charge is balanced by the opposite-ions that are placed part in the spacing between layers of the clay. The thickness of the layers or platelets is of the order of 1 nm and the scale of the relationship between dimensions is 100-1500. The molecular weight of platelets. { 1.3x10} it is considerably higher for most polymers. Furthermore, the platelets are not all rigid but have some degree of flexibility. They also have very high surface areas, several hundred square meters per gram. They are also capable of ion exchange capabilities. The clays, due to their nature of charge, are in general highly hydrophilic species and therefore are incompatible with polymer systems. In this way, a necessary requirement to make clays compatible with polymers is to alter their polarity and make them organophilic. This is achieved by ion exchange of the hydrophilic clay with an organic cation such as an alkylammonium ion. In montomorillonite, the sodium ions in the clay can be exchanged for an amino acid such as 12-amidodecanoic acid (ADA.). Na'-ARCILLA + HO_C-R-NH + C1"- > HO ^ CR-NH3 '-ARCILLA + NaCl In addition to montmorillonite and hectorite other synthetic clays such as hydrotalcite can be produced in a very pure form and can carry a positive charge on the platelet.The final nanocomposite can be interspersed or exfoliated. interleaved system, the organic polymer (PVdC) can be inserted between the layers of clay so that the spacing between platelets expands but the layers still maintain a well-defined spatial relationship with each other. In exfoliation the platelets are completely separated and the individual layers are distributed through the polymer matrix (PVdC). By modifying the surface polarity of the clay, onium ions can allow thermodynamically favorable penetration of polymer precursors into the interlayer region. The ability of onium ions to aid in the destruction of clay depends on its chemical nature such as its polarity. For positively charged clays such as hydrotalcite, onium salt modification is replaced by use of an ionic surfactant. Other types of clay modifications include ion-dipole interactions, silane coupling agents and the use of block copolymers and graft copolymers. The PVdC-Nanoarcilla nanocomposites in connection with the invention can be prepared by free radical suspension polymerization or free radical emulsion polymerization. A nanoclay suspension is predispersed in a water phase with appropriate suspending agents and pH adjusted to 6 to 8. This suspension is pumped to the polymerization reactor when the polymer conversion has reached at least 20%. The reaction continues after the addition of the nanoclay suspension until the desired polymer conversion is achieved. Another method that can be used is to add the nanoclay suspension to the reactor after the specified polymer conversion is reached and the reaction is terminated. In both cases, the appropriate reaction agitation is maintained, or increases if there is an elevation in the viscosity of the system, and sufficient time must be allowed to achieve the desired exfoliation of the nanoclay. Typical steps of PVdC suspension polymerization can be followed. These steps include the preparation of monomers such as vimlidene chloride (CH2 = CC12) and villous chloride, and the use of water, initiators, suspending agents, antioxidants, etc. The monomer units can also be derived from styrene, vinyl acetate, acplonitplo and C? -C12 alkyl ester of (meth) acrylic acid (e.g., methylacrylate, butylacrylate, methylmethacrylate, etc.) The production of PVdC (Saran) is well known in the industry. The reactor preparation includes purging with nitrogen, heating at reaction temperature, stirring the mixture of water, monomers and other additives at the desired stirring speed. The reaction is then started, and the reaction is carried to the defined conversion. After it is complete, the polymer can be separated from unreacted monomers, washed and separated from water and dried. The dried nanocomposite is then formulated with appropriate processing additives and made into a film. The processing additives may be added to the reactor or subsequently mixed. Figure 1 of the present specification shows a monolayer film 10 having a single layer 11.

The layer 11 comprises the silicate nanocomposite in layers of polyvinylidene chloride of the invention. Figure 2 shows a film 20 finger layers having a layer 21 and a layer 22. The layer 21 comprises the silicate nanocomposite of polyvinylidene chloride layers described above for layer 11 of Figure 1. The layer 22 can comprise any suitable polymeric material, such as a thermoplastic polymeric material, such as an olefinic polymer, such as an ethylenic polymer, such as an ethylene homopolymer or copolymer, such as an ethylene / alpha-olefin copolymer, such as heterogeneous or homogeneous ethylene copolymers / alpha-olefin. Layer 22 may comprise an olefin polymer or copolymer such as ethylene / vinyl acetate copolymer, ethylene / alkylacrylate copolymer, ethylene / methacrylic acid copolymer; ionomer, homopolymer and propylene copolymer; and butylene homopolymer and copolymer. Mixtures of any of the materials described herein for layer 22 can be included in layer 22.

Figure 3 shows a three layer film 30 having layers 31, 32, and 33. The layer 31 comprises the silicate nanocomposite of polyvinylidene chloride layers described above for layer 11 of the Figural. Layers 32 and 33 comprise any of the polymers described above for layer 22 of Figure 2. Layers 32 and 33 may be the same, or they may be different. The difference can be in composition, in one or more physical properties, in thickness, in quantity or type of additives, in degree of cross-linking or orientation, or the like. For example, layer 32 may comprise ethylene / vinyl acetate with 6% vinyl acetate, while layer 33 may comprise an ethylene / vinyl acetate with 9% vmyl acetate. As another example, layer 32 may comprise ethylene / villi acetate with 6% villi acetate, while layer 33 may comprise an ethylene / alpha-olefin copolymer. The film structures according to the invention can thus be illustrated as A / B / A or as A / B / C, where A, B and C each represents a different layer of a multilayer film. The multilayer film structure according to one embodiment of the present invention has at least four layers. Said film 40 (see Figure 4) includes a seal layer 43, a volume layer 44, a barrier layer 41 comprising the silicate nanocomposite in layers of polyvinylidene chloride, and a layer 42 of abuse. . The layers 43, 41 and 42 may correspond in composition to any of the layers 22, 32 and 33 of the previous figures. The volume layer 44 may be disposed between the seal layer 43 and the O-barrier layer 41, and the barrier layer 41 of 02 may be disposed between the volume layer 44 and the abuse layer 42. If desired, tie layers, comprising polymeric adhesives, may be disposed between the seal layer 43 and the volume layer 44, as well as between the barrier layer 41 and the abuse layer 42. The volume layer 44 may comprise any of the materials described for layers 32 and 33 of Figure 3. The film of the present invention may have any desired total thickness, so long as the film provides the desired properties for the intended end use . Thicknesses can vary from 0.1 to 20 mils, such as 0.3 to 16 mils, 0.5 to 12 mils, 0.7 to 8 mils, 1.0 to 8 mils and 1.3 to 4 mils. Figure 6 shows a conventional blister pack 50 for packaging pharmaceutical products such as tablets. The cover 52 is attached to the base 56 in the shoulders 54 of the base 56 (see also figure 5). A plurality of recesses 58, each designed to accommodate a tablet, capsule, or other pharmaceutical producer, are covered by the lid 52. The lid 52 is conventionally a thin sheet of metal or metallized. Figure 5 shows a longitudinal section through the ampule package 50. The base 56 with recesses 58 makes contact with the cover 52 in the shoulders 54. In the region of the shoulders 54 the cover 51 is joined to the base 56, eg, by means of sealing or adhesive bonding (sealing / adhesive not shown) for clarity purposes). Figure 7 shows a cross section through blister pack 50 with its base 56, cover 52 and recesses 58. Figure 8 shows an expanded fragmentary sectional view of blister pack 50, using film of the present invention. The base 56 is made of an inner film 62 and an outer film 60. The inner film 62 comprises the film of the present invention. The film 62 can be a flat lay flattened film. This film can provide good MVTR (low) as well as low OTR for pharmaceutical applications. The outer film 60 can be any suitable film, such as the PVC film (polyvinyl chloride) used in some blister packs. Alternatively, the base may comprise a single film comprising the film of the present invention, without the need for an additional 60 movie. In another alternative, the film of the invention may comprise the outer film, and another film may form the inner film 62. Those skilled in the art will understand that various combinations can be made, provided that a film of the invention is present in the base. In yet another embodiment, the film of the invention can form the lid of the blister package, and a conventional thin sheet or plastic film can form the base. Films 62 and 60 can be bonded together by any suitable means, such as lamination, coextrusion, extrusion coating, extrusion lamination, heat sealing, gluing, etc.

The base of the present blister pack can be enhanced, deep drawn or vacuum configured. The cap in one embodiment may comprise a thin sheet of aluminum or a laminate containing thin foil of aluminum, or a plastic which exhibits low elasticity and low drawing properties. The base may have, e.g., from 6 to 30 recesses in the form of cups or plates. The recesses are surrounded by a shoulder, the shoulder forming an interconnected plane. The base can be prepared, e.g., as an endless strip with the contents in the recesses and joined to the lid, in particular in the form of a thin lid sheet, likewise in the form of an endless strip. The cover covers the base completely and, eg, by means of sealing or adhesive bond is attached to the base in the shoulders. The lid can be sealed or adhesively bonded to the shoulder through the entire area or, by selecting a special sealing tool or link pattern for the purpose, this seal or link may be only partial. Then, the capped endless strip can be cut to the desired size. This can be done, e.g., using a stamping tool. At the same time, the blister pack can receive external contours, or it is possible to provide weaknesses in the cap material base in order to allow the blister pack to bend or create cap segments, facilitating the removal of the cap segment and removal of possible contents. The polyvinylidene chloride layered silicate nanocomposite of the invention can include any suitable vinylidene chloride-containing copolymer, i.e., a copolymer including monomer units derived from vinylidene chloride (CH2 = CC12) and also derived monomer units of one or more of vinyl chloride, styrene, vinyl acetate, acrylonitrile, and alkyl esters of C-CL_ of (meth) acrylic acid (e.g., methylacrylate, butylacrylate, methyl methacrylate, etc.). In this way the appropriate PVdC resins include, eg, one or more vinylidene chloride / vinyl chloride copolymer, vinylidene chloride / methylated copolymer copolymer, vinylidene chloride / acrylonitrile copolymer, vinylidene chloride copolymer. vmylidene / butyl acetate, vinylidene chloride / styrene copolymer and copolymer of vinylidene / vinyl acetate copolymer. The weight percent of the vmylidene chloride monomer is preferably from 75% to 96% by weight of the copolymer exclusive of the nanosilicate content; the weight percent of the second monomer, eg, vinyl chloride, is preferably 4% to 25% by weight of the copolymer exclusive of the nanosilicate content. The stabilizer of the invention may include one or more of: 1) epoxidized compounds, such as epichlorhydram / bisphenol A, epoxidized soy bean oil, epoxidized flaxseed oil, butyl ester of epoxidized linseed oil fatty acid ester , epoxidized octyl talate, epoxidized glycol dioleate, and the like, and mixtures thereof; 2) oxidized polyethylene; 3) 2-ethylhexyl diphenyl phosphoate; 4) chlorinated polyethylene; 5) di) 2-ethexhoate) of tetraethylene glycol; 6) a metal salt of a weak inorganic acid, e.g., tetrasodium pyrophosphate; 7) a soap of a fatty acid, e.g., calcium ricmoleate; and 8) a hydrotalcite such as magnesium aluminum hydrocarbonate available from MITSUIMR under the trademark DHT4AMK, or ALCAMIZERMK 1 available from Kisu to Chemicals. Commercial examples of epoxidized compounds include epichlorohydrin / bisphenol A, an epoxy resin available from Shell as EPONMR 828; epoxidized soy bean oil, available from Viking Chemical Company as VIKOFLEXMR 7177; epoxidized flax seed oil, available from Viking Chemical Company as VIKOFLEXMR 7190; butylated fatty acid ester of epoxidized linseed oil, available from Viking Chemical Company as VIKOFLEXMR 9040; epoxidized ocdyllolate, available from C. P. may Company as Monoplex S-73; and epoxidized glycol dioleate, available from C. P. may Company as MONOPLEXMR S-75. The stabilizer may comprise 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 parts by weight of the silicate nanocomposite composition in layers of polyvinylidene chloride of the invention, such as 0.5 to 5, such as from 1 to 3, such as from 1.5 to 2 parts by weight of the polyvinylidene chloride layered silicate nanocomposite composition of the invention. Commercial examples of a stabilizer include FERROMR PLASCHEK ™ 775, an epoxidized soy bean oil, and calcium ricinoleate available from Acme-Hardesty Company. The polymeric processing aid of the invention may include one or more of: 1) a fatty acid soap, e.g., calcium ricinoleate; 2) a terpolymer having an acrylate comonomer, such as methyl methacrylate / butylacrylate / styrene terpolymer; methyl methacrylate / bitylacrylate / butyl methacrylate terpolymer; or mixtures thereof; 3) hydroxy stearamide of n- (2-hydroxymethyl) -12; Y 4) propylene glycol mono-ricinoleate. The polymeric processing aid may comprise 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 parts by weight of the silicone nanocomposite composition in layers of polyvinylidene chloride of the invention; e.g., the polymeric processing aid comprises from 0.5 to 5, such as from 1 to 3, such as from 5 to 2 parts by weight of the silicate nanocomposite composition in polyvinylidene chloride layers of the invention. A commercial example of a polymeric processing aid is ELF ATOCHEMMK METABLENMR L1000, an acrylic polymer processing aid. It will be appreciated that a fatty acid soap, e.g., calcium ricinoleate, can function as both a stabilizer and a polymeric processing aid. In this embodiment, the fatty acid soap may comprise 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 parts by weight of the silicate nanocomposite composition in layers of polyvinylidene chloride of the invention. For example, the soap of a fatty acid can comprise from 0.5 to 5, such as from 1 to 3, such as from 5 to 2 parts by weight of the silicate nanocomposite composition in layers of polyvinylidene chloride of the invention. Other polymeric co-stabilization processing aids may optionally be included in the composition, such as HENKELMK LOXIOLMR VPOG1732, a full high molecular weight ester, and CASCHEMMR CASTOWAXMR NF, a hydrogenated castor oil. The nanosilicate of the invention may include one or more clays of the phyllosilicate group, including one or more of: 1) dioctahedral clays such as montmorillonite, beidellite, and nontronite, and 2) trioctahedral clays such as saponite, hector, and sauconite; and in particular modified forms with oxonium ion of these clays. The nanosilicate can comprise 0.1, 0.5, 1, 2, 3, 4, 5, 6, 76, 8, 9, or 10 parts by weight of the silicate nanocomposite composition in layers of polyvinylidene chloride of the invention, e.g., the nanosilicate may comprise from 0.5 to 8, such as from 1 to 5, as well as from 1.5 to 4 parts by weight of the silicate nanocomposite composition in layers of polyvinylidene chloride of the invention. Commercial examples of nanosilicates include CLOISITEMI 20a and CLOISITEMK 15a, which are modified montmorillonite clay with oxonium ion from Southern Clay Products; NANOMERMK I.31PS, which is a modified montomorillonite clay with Nancor oxonium ion; BENTONEMK 108 and BENTONEMK 166k, which are hectopta clay (also a subset of smectite, the BENTONEMR clays available from Elementis Specialties, a nanotalco having the Mg3S? O? (OH) composition available from Nanova LLC, and a nanotalco (phyllosilicate ) available from Argonne National Laboratory Optionally, the composition and film of the invention may include an acid cleaner (hydrogen chloride) If present, the acid cleaner may comprise from 0.1 to 4, such as from 0.5 to 2, parts by weight of the composition of silicate nanocomposite of polyvinylidene chloride layers of the invention A commercial example of an acid cleaner is MITSUIMR DHT4A, a magnesium aluminum hydroxycarbonate of formula Mg4.5 l2 (OH)] C033.5H20 An alternative material is tetrasodium pyrophosphate (STPP) .The determination of the total thermal stability of the silicate nanocomposite composition in layers of polyvinylidene chloride of the invention can be carried out by working the composition between a pair of heated rollers or inside a heated mixing chamber. The time required to produce a notorious blackened polymer due to decort degradation and temperature induced degradation is a measure of the effectiveness of the thermal stability of the composition. Commercially acceptable vinylidene chloride copolymer blends show thermal stability times of at least 10 minutes in a mixing device such as a BRA-BENDERMR mixer operating at about 168 ° C (335 ° F) and 63 revolutions per minute. The composition of the invention can be extruded and processed into any of a number of methods known to those skilled in the art so as to form a film or a layer of a multilayer film., for example, by the methods described in U.S. Patent Nos. 3,741,253 (Brax et al.), 4,278,738 (Brax et al., and 4,284,458 (Schirmer) all incorporated herein by reference in their entirety. , any suitable method for making a film having an oxygen barrier layer can be used to make a film according to the present invention, as long as the method uses a silicate nanocomposite composition in layers of polyvinylidene chloride described above. Suitable methods include coextrusion tubular molding, such as that shown in U.S. Patent 4,551,380 (Schoenberg), hereby incorporated by reference in its entirety, flat tubular or melt extrusion, blown bubble extrusion (monolayer films) or coextrusion (for multilayer films) by techniques well known in the art.Multilayer films can be made by co-extrusion , extrusion coating, extrusion lamination, crown bonding or conventional lamination of all film layers. A method for producing a multilayer film having a PVdC layer is described in U.S. Patent No. 4,112,181, issued September 5, 1978 to Baird, Jr. , et al., incorporated herein by reference in its entirety. This patent describes a method for coextruding a tubular film where the walls of the tube have at least three layers, a central layer being a layer of PVdC. The tubular film is subsequently biaxially oriented by the trapped bubble technique. The 3-layer film can be crosslinked by electron beam irradiation. A satisfactory method for producing a multi-layer saucer film is described in US Patent No. 3,741,3253, issued June 26, 1973 to Brax et al., Incorporated herein by reference in its entirety, which describes a multi-layered, biaxially oriented film having a PVdC barrier layer. This film is made by an extrusion coating process in which a substrate layer or layers of a polymer such as polyethylene or ethylene vinyl acetate copolymer is extruded into the form of a tube, cross-linked by irradiation, and inflated . One layer of PVdC is extruded into the inflated pipe, and another layer or layers of polymer is coated by extrusion simultaneously or in sequence to the PVdC. After cooling, this multi-layer tubular structure is flattened and rolled up. Then, the tube is inflated, and heated to its orientation temperature, thereby orienting the film biaxially. The bubble cools quickly to adjust the orientation. This process produces a heat shrinkable barrier film with low oxygen permeability. Also, the advantages of a crosslinked film are provided without subjecting the PVdC layer to irradiation which tends to degrade the satan. The barrier layer in the examples of the Brax et al patent is a plasticized copolymer of vinylidene chloride and devinyl chloride. The film of the invention can be crosslinked or non-crosslinked, oriented or non-oriented, heat shrinkable or non-heat shrinkable. When the film is heat shrinkable, it has a total free shrink at 85 ° C (185 ° F) from 10 to 100%. All or a portion of the film of the present invention can be irradiated to induce crosslinking. In the irradiation process, the film is subjected to a treatment of energetic radiation, such as corona discharge, plasma, flame, ultraviolet, X-rays, gamma rays, beta rays, and high-energy electronic treatment, which induces cross-linking between the molecules of the irradiated material. The appropriate dosage level can be determined by conventional dosimetry methods known to those of ordinary skill in the art, and the precise amount of radiation to be used., of course, depends on the particular movie structure and its final use. The film can be irradiated at a level of 0.5-10 megarad (MR) (5 to 150 kGrays), such as 1-12 MR. Further details on the irradiation of polymer films can be found, for example, in U.S. Patent Nos. 4,064,296 (Bornstein et al.), 4,120,716 (Botet), and 4,879,430 (Hoffman), all incorporated herein by reference. The films of the invention can be made by tubular coextrusion, and by extrusion coating. In the latter case, a substrate is extruded or coextruded, optionally irradiated, then optionally oriented by stretching, and then a layer of the silicate nanocomposite of polyvinylidene chloride layers as described herein is coated by extrusion, optionally with when minus one additional layer, to the substrate. The films of the invention can have the following structures: Film Structure A / BA / CB / A / BC / A / CC / A / BB / A / D / BC / A / D / CC / A / D / B Where A = silicate nanocomposite in chloride layers polyvinylidene. B, C, and D = any of the materials described above for layers 43, 44 and 42, respectively of Figure 4. The polymectic components used to make film according to the present invention may also contain appropriate amounts of other additives normally included in or mixed with said compositions. These include slip agents, antioxidants, fillers, dyes, pigments, radiation stabilizers, antistatic agents, elastomers, and other additives known to those of experience in the packaging film industry. The multilayer film of the present invention can have any total number of layers and any desired total thickness as long as the film provides the desired properties for the particular packaging operation in which the film is used. The film layer comprising PVdC (silicate nanocomposite in layers of polyvinylidene chloride) can be irradiated up to a dosage level of 15 MR without significant change (degradation) of the film. However, chlorinated species are generated and may not be accepted by the FDA. As is known to those of skill in the art, the use of a polymer comprising mer units derived from vmylidene chloride and methylacplate reduces the effect of irradiation degradation in the PVdC. The film of the invention can be laminated, adhesively adhered, extrusion coated, or laminated by extrusion to a substrate to form a laminate. Lamination can be achieved by bonding layers with adhesives, bonding with heat and pressure, and still coating by dispersion and extrusion coating. The film of the present invention is especially suitable for packaging applications in which the products being packaged must be protected from the atmospheric O. More particularly, the film according to the present invention is especially useful as ampoule packing for pharmaceuticals, as a film suitable for use as a barrier bag, and as a film suitable for use in a patch bag.

A blister pack can be made, with the PVdC composition described above and the film made therefrom, by conventional techniques and in a conventional packaging format. Table 1 Predictive OTR and MVTR data table for silicate nanocomposite in layers of polyvinylidene chloride vnc / MA ooprw 0 50 0.15 'NanocßnwDUcsto ESO 2? r '«of poltaertra- PA 2phr tion of susnen- Napoialc7 8p r Ision in-situ VDC MA" 100phr 040 0 16 Numoi-ompu sto ESO 2pt? r of polymeriza¬ PA 2p rion of suspension 1 Nanotatc '2phr scón ta-iitu, VDC / MA0100phr 0 25 0 10 Nanocomposite, ESO 2pnr (le polinieriza- PA 2pnr tiPnr of sucn- Nanotalc7 4phr iStón in-situ VDC? / C 100phr 0 80 0 25 jNanoconi post ESO 1 phr of polymerization AS10 i p r tion of 9USIMM1-; Manolalc '4p in situ situ VDC / MA "100pl? R I 0.15 008 | Nanocop? P? Cestn¡ i ESO 1 phr | dc pßlDuaerizui I, 1phr of your? &Tt- I Nanotalc 4p r Isión in-situ Notes to Table 1 1. 6-9"by weight of MA comonomer 2: Epoxidized soy bean oil 3: Polymer processing aid 4: Smectite clay surface (montmorillonite) treated with organic quaternary ammonium salt 5: Natural smectite from Southern Clay Products Inc. 6: Natural Montmorillonite from Elementis Specialties 7: Argonne National Labs 8: 3-6?) Frosilicate nanotalco by weight of MA comonomer 9: VDC-VC, where the by weight of the vinyl chloride is between 8 and 14% by weight of the VDC-VC.10: AS copolymer as an acid cleaner Note also that "phr" means 453.6 grams percent (pounds per hundred) (units by weight) In this way, by way of example, in the film of the first comparative example, the equivalent of 45.36 kg (100 pounds) of the VFDC / MA resin was mixed with 907 grams (2 pounds) of the polymeric processing aid. An equivalent to phr is "parts by weight". For the examples the VDC / MA is listed separately from Nanotalc (the nanosilicate) to indicate relative amounts of each material present in the examples, but it will be understood that the nanosilicate does in fact form part of the silicate nanocomposite structure in chloride layers. polyvinylidene. Additional Prophetic Examples Example 10 A four-layer film is co-extruded by a hot-blow process such as an annular tube, the film having the construction: Where: EVAi = EVA with 3.3% by weight of vinyl acetosate content, available from Huntsman as PE1335MK, PVdC = silicate nanocomposite in layers of polyvinylidene EVA. = EVA with 28% by weight of vinyl acetate content, available from DuPont as EL-VAXMR3182-2.

After extrusion, the tubular co-extruded one collapses on itself to form a laid flat film having the construction: EVAi / EVA_ / PVdC / EVA ^ / / EVA ^ / PVdC / EVA / EVAi A preferred thickness for each layer of PVdC It is 0.75 mils. Example 11 A four layer film, like that of the previous example, is made by a melt coextrusion process, but where the outer EVA layer is replaced with an LLDPE. The film in this way has the construction: LLDPE / EVA2 / PVdC / EVA ,. Two commercial LLDPE resins, each useful for this Example, are DOWLEX 2045.03 and DOWLEX 2045.04, each available from Dow. Each of these is a deethylene / octene-1 copolymer with an octene content of 6.5% by weight, and a density of 0.920 grams / cc.

Claims (1)

CLAIMS 1. A polymeric film comprising at least one layer, the at least one layer comprising a silicate nanocomposite composition in layers of polyvinylidene chloride comprising: a) 100 parts, by weight of the composition, of a nanocomposite of silicate in layers of polyvinylidene chloride; b) from 0.1 to 10 parts, by weight of the composition, of a stabilizer; and c) from 0.1 to 10 parts, by weight of the composition, of a polymeric processing aid. 2. The film according to claim 1, wherein the stabilizer is selected from the group consisting of: a) epoxidized compounds; b) oxidized polyethylene; c) 2-ethyl hexyl diphenyl phosphate; d) chlorinated polyethylene; e) di (2-ethylhexoate) of tetraethylene glycol; f) a metal salt of a weak inorganic acid; and g) a hydrotalcite. 3. The film according to claim 2, wherein the epoxidized compounds are selected from the group consisting of epichlorohydrin / bisphenol A, epoxidized soy bean oil, epoxidized seed linseed acdeite, fatty acid butyl ester of epoxidized flax seed oil, epoxidized octyl talate, and epoxidized glycol dioleate. 4. The film according to claim 1, wherein the polymeric processing aid is selected from the group consisting of: a) a terpolymer having an acrylate comonomer; b) n- (2-hydroxyethyl) -12-hydroxy stearamide; and c) propylene glycol mono-ricinoleate. 5. The film according to claim 4, wherein the terpolymer having an acrylate comonomer is selected from the group consisting of terpolymer methyl methacrylate / butylacrylate / styrene; and methyl methacrylate / butylacrylate / butyl methacrylate terpolymer. 6. The film according to claim 1, wherein the layered silicate nanocomposite of polyvinylidene chloride comprises a hydrophilic clay of the fillosilicate group, the clay selected from the group consisting of: a) dioctahedral clays; and b) arci l las tpoctahédpcas. 7. The film according to claim 6, wherein the hydrophilic clay is selected from the group consisting of montmorillonite, beidellite and nontronite. 8. The film according to claim 6, wherein the hydrophilic clay is modified with oxonium ion. 9. The film according to claim 1, comprising an acid cleaner. 10. A polymeric film comprising at least one layer, the at least one layer comprising a silicate nanocomposite composition in layers of polyvinylidene chloride, the composition comprising: a) 100 parts, by weight of the composition, of a nanocomposite of silicate in layers of polyvinylidene chloride; and b) from 0.1 to 10 parts, by weight of the composition, of a soap of a fatty acid. 11. The polymeric film according to claim 10, wherein the soap of a fatty acid comprises calcium ricinoleate 12. The film according to claim 10, wherein the layered silicate nanocomposite of polyvinylidene chloride comprises a hyphrophilic clay of the fillosilicate group, the clay selected from the group consisting of: a) dioctahedric clays; and b) trioctahedric clays. 13. The film according to claim 12, wherein the hydrophilic clay is selected from the group consisting of montmorillonite, beidellite, and nontronite. 14. The film according to claim 12, wherein the hydrophilic clay is modified with oxonium ion. 15. The film according to claim 10, wherein the composition comprises an acid cleaner. 16. A blister pack comprising: a) a base, the base comprising I) a plurality of recesses, and II) a shoulder surrounding the recesses b) a cover attached to the shoulder; and c) contents arranged in the respective recesses; wherein at least one of the base and cap comprises a silicate nanocomposite composition in layers of polyvinylidene chloride, the composition comprising I) 100 parts, by weight of the composition, of a silicate nanocomposite in layers of polyvinylidene chloride; II) from 0.1 to 10 parts, by weight of the composition, of a stabilizer; and III) from 0.1 to 10 parts, by weight of the composition, of a polymeric processing aid. 17. The ampule package according to claim 16, wherein the stabilizer is selected from the group consisting of: a) epoxidized compounds; b) oxidized polyethylene; c) 2-ethyl hexyl diphenyl phosphate; d) chlorinated polyethylene; e) di (2-ethylhexoate) of tetraethylene glycol; f) a metal salt of a weak inorganic acid; and g) a hydrotalcite. 18. A blister pack according to claim 16, wherein the polymeric processing aid is selected from the group consisting of: a) a terpolymer having an acrylate comonomer; b) n- (2-hydroxyethyl) -12-hydroxy stearamide; and c) propylene glycol mono-ricinoleate. 19. The blister pack according to claim 16, wherein the nanocomposite desilicate in layers of polyvinylidene chloride comprises a hydrophilic clay of the smectite group, the clay selected from the group consisting of: a) clay-dichloride; and b) arcillastrioctahédricas. 20. A blister pack comprising: a) a base, the base comprising I) a plurality of recesses, and II) a shoulder surrounding the recesses; b) a cover fixed to the shoulder; and c) contents arranged in respective recesses; wherein at least one of the base and top comprises silicate nanocomposite composition in layers of polyvinylidene chloride, the composition comprising: I) 100 parts, by weight of the composition, of a silicate nanocomposite in layers of polyvinylidene chloride; and II) from
1. 01. to 10 parts, by weight of the composition, of a soap of a fatty acid.