KR20080007337A - 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 including 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

Polyvinylidene chloride laminated silicate nanocomposite and film produced therefrom {POLYVINYLIDENE CHLORIDE LAYERED SILICATE NANOCOMPOSITE AND FILM MADE THEREFROM}

FIELD OF THE INVENTION The present invention relates to polyvinylidene chloride laminated silicate nanocomposites and films suitable for packaging drugs in compositions and films, such as blister packs, prepared therefrom.

This application claims the benefit of priority to US Provisional Application No. 60/666213, filed March 29, 2005, the content of which is incorporated herein by reference.

Conventional blister packs typically include a base having a recess surrounded by one or more typically a plurality of shoulders, and a lid attached to the shoulder. Tablets, capsules or other contents are contained within each recess and (1) pressurized on each recess to allow the contents to penetrate the lid (usually aluminum foil, etc.), or (2) on the recess. It can be removed from the recess by removing a portion of the lid to access the contents of the recess.

In fact, the base is formed of a recess and a shoulder defining a base material between the recesses; The recess of the base is filled with a tablet or the like; The base with filled recesses is covered with a lid, which is sealed or otherwise attached to the shoulder of the base.

The interior of the base of the blister pack is often composed of an internal part (attached to the lid) of ACLAR ™ PTFE (polychlorotrifluoroethylene), which is a very expensive material and has less than optimum oxygen barrier properties. This material typically exhibits a water vapor transmission rate (MVTR) of about 0.4 g / m ² per mil of thickness. The sheath of the base is often PVC (polyvinyl chloride) with a thickness of about 250 micrometers (10 mils). PVC, polyamides, polyolefins, polyesters are other materials that can be used to make the base. The aluminum foil can be attached to the base.

The lid is typically made of aluminum foil or an aluminum foil stack. Aluminum foil is the preferred material for the lid on the blister pack because the thickness of the material used requires relatively little force for the material to rupture. As a result, the transmission energy is low and aluminum essentially shows no elasticity at all. Plastic laminates may also be used in the lid.

Some blister packs are characterized by a weak line in the region of each recess provided in the lid. For other blister packs, each recess may be covered by a separate cover section. A grabbing strap may be present in the weak line or on each cover section, allowing the individual recesses to be exposed by peeling off the back side of the cover section.

The provision of vinylidene chloride copolymer, often referred to as "saran" or "PVdC" in PVdC compositions, which can provide low oxygen permeation rate (MVTR) as well as low oxygen permeation rate (OTR) to the packaging film, provides oxygen And blister packaging of drugs that are sensitive to both moisture.

Stabilizers are often used to formulate PVdC-based compositions. This stabilizer reduces the thermal degradation of the PVdC formulation during the extrusion process. Unfortunately, OTR and thermal stability are often at odds in designing such formulations. Thus, compositions with increased amounts of stabilizer often improve thermal stability but at the expense of oxygen barrier properties. In contrast, improved (low) OTR can be obtained by lowering the relative amount of stabilizer in the formulation, but this can result in a less stable PVdC composition.

US Pat. No. 6,673,406 to Bekele, which is hereby incorporated by reference in its entirety, discloses a composition in which a hydrophilic clay, such as modified montmorillonite, is blended with PVdC and the blend is incorporated into a polymeric film having one or more layers. Films are disclosed.

Nanosilicates can be used in natural (clay) or synthetic grades. Natural grade nanosilicates have been found to have a tendency to not disperse well when bulk blended into PVdC. Because of this low dispersibility, the oxygen barrier properties of films made from PVdC / natural nanosilicate blends will not necessarily improve.

Modified grade nanosilicates have better dispersibility than natural grade nanosilicates and therefore generally have better oxygen barrier properties. However, the surface treatment used to modify the nanosilicates is based on alkyl quaternary ammonium chlorides. Regardless of the alkyl component of this salt, this material has been found to adversely affect the thermal stability of PVdC when blended into PVdC.

It has also been found that limitations exist for both natural and modified grade nanosilicates when using an extrusion coating process. Extrusion coating is a well known method for making shrinkable bags containing PVdC. In general, in the extrusion coating process, less than 4% by weight of the PVdC blend may consist of nanosilicates.

Therefore, there is a need to solve the problems caused by dispersibility, thermal stability, and bulk blending nanosilicates into PVdC.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic cross-sectional view of a monolayer film.

2 is a schematic cross sectional view of a two-layer film.

3 is a schematic cross-sectional view of a three layer film.

4 is a schematic cross-sectional view of a four layer film.

5 is a longitudinal cross section through the blister pack.

6 shows a top view of the blister pack of FIG. 5.

7 shows a cross-sectional view of the blister pack of FIG. 6.

FIG. 8 shows an extended fragmentary cross sectional view of the blister pack of FIG. 6.

In a first aspect, the composition comprises polyvinylidene chloride laminated silicate nanocomposites.

In a second aspect, the polymeric film comprises one or more layers comprising polyvinylidene chloride laminated silicate nanocomposites.

In a third aspect. The polymeric film comprises 100 parts polyvinylidene chloride laminated silicate nanocomposite based on the weight of the composition, 0.1 to 10 parts stabilizer based on the weight of the composition, and 0.1 to 10 parts polymeric processing aid based on the weight of the composition. At least one layer comprising a polyvinylidene chloride laminated silicate nanocomposite composition.

In a fourth aspect, the polymeric film comprises 100 parts polyvinylidene chloride laminated silicate nanocomposite based on the weight of the composition, and 0.1 to 10 parts fatty acid soap based on the weight of the composition, polyvinylidene chloride laminated silicate nanocomposite At least one layer comprising the composition.

In a fifth aspect, a blister pack includes a base comprising a plurality of recesses and a shoulder surrounding the recesses; A cover part attached to the shoulder; And contents disposed in each recess, wherein at least one of the base and the lid portion is 100 parts polyvinylidene chloride laminated silicate nanocomposite based on the weight of the composition, 0.1 to 10 parts by weight of the composition Polyvinylidene chloride laminated silicate nanocomposite compositions comprising 0.1 to 10 parts by weight of the composition and a polymeric processing aid based on the weight of the composition.

In a sixth aspect, a blister pack includes a base comprising a plurality of recesses and a shoulder surrounding the recesses; A cover part attached to the shoulder; And contents disposed in each recess, wherein at least one of the base and the lid portion is 100 parts polyvinylidene chloride laminated silicate nanocomposite based on the weight of the composition, and 0.1 to 10 parts based on the weight of the composition. Polyvinylidene chloride laminated silicate nanocomposite compositions comprising fatty acid soaps.

In a seventh aspect, the polyvinylidene chloride laminated silicate nanocomposite composition comprises 100 parts polyvinylidene chloride laminated silicate nanocomposite based on the weight of the composition; 0.1 to 10 parts stabilizer based on the weight of the composition; And from 0.1 to 10 parts of a polymeric processing aid, based on the weight of the composition.

In an eighth aspect, the polyvinylidene chloride laminated silicate nanocomposite composition comprises 100 parts polyvinylidene chloride laminated silicate nanocomposite based on the weight of the composition; And 0.1 to 10 parts fatty acid soap based on the weight of the composition.

Justice

As used herein, "polyvinylidene chloride laminated silicate nanocomposites" and "PVdC laminated silicate nanocomposites" and the like refer to polymers prepared in situ in a suspension process and / or an emulsification process. In-situ processes enable polymer infiltration that results in finite expansion of the silicate crystals resulting in an intercalated polymer / clay hybrid. Exfoliation of a wide range of polymer penetrations and delamination of the silicate crystallites is achieved to form nanoscale silicate layers suspended in the PVdC matrix. In the process for producing the polymers of the present application, the highly polar aqueous dispersion of nanoclays is previously dispersed in the monomer pre-mixture before polymerization. Nanoclay may be kaolin, talc, smectite, vermiculite or mica. The pre-dispersion of the nanoclay can be as high as 10% based on the total monomer content of the suspension. After the pre-mix is prepared, the conventional polymer step and the post polymerization step are carried out. The result is a C ₁ -C ₁₂ alkyl ester of vinylidene chloride monomers and comonomers such as vinyl chloride, styrene, vinyl acetate, acrylonitrile, and (meth) acrylic acid (eg, methyl acrylate, butyl acrylate, Methyl methacrylate, etc.) and also contain up to 10% of the nanosilicates by weight of the composition.

"(Meth) acrylic acid" as used herein refers to both acrylic acid and / or methacrylic acid.

As used herein, "(meth) acrylate" refers to both acrylates and methacrylates.

As used herein, "polymer" refers to the product of a polymerization reaction and includes homopolymers, copolymers, terpolymers, quaternary polymers, and the like.

"Copolymer" herein refers to a polymer formed by the polymerization of two or more different monomers and includes random copolymers, block copolymers, graft copolymers, and the like.

"Ethylene / alpha-olefin copolymer" (EAO) herein refers to an air of ethylene with one or more comonomers selected from C ₃ to C ₁₀ alpha-olefins such as propene, butene-1, hexene-1, octene-1 and the like. Refers to coalescence, wherein the molecules of the copolymer comprise polymer long chains with relatively few side chain branches resulting from alpha-olefins reacted with ethylene. This molecular structure is in contrast to conventional high pressure low or medium density polyethylenes highly branched to EAO, which comprise both long and short chain branches. EAO includes Linear Medium Density Polyethylene (LMDPE), Linear Low Density Polyethylene (LLDPE), Ultra Low Density Polyethylene (VLDPE) and Ultra Low Density Polyethylene (ULDPE), such as DOWLEX ™ or ATTANE ™ Resin or Exxon supplied by Dow Heterogeneous materials such as ESCORENE ™ or EXCEED ™ resins supplied by; And TAFMER ™ resin supplied by Mitsui Petrochemical Corporation, EXACT ™ resin supplied by Exxon, long chain branched (HEAO) AFFINITY ™ resin supplied by Dow Chemical Company, or DuPont Elastomers Linear homogeneous ethylene / alpha-olefin copolymers (HEAO) such as ENGAGE ™ resin supplied by Dow Elastomers).

"Package" herein refers to a film arranged around a product.

"Film" herein refers to a plastic web material having a thickness of 0.05 mm (20 mils) or less, such as 0.25 mm (10 mils) or less.

A “bonding layer” herein refers to a film layer that may be involved in bonding the film to the film layer itself or to another layer.

“Joining” herein refers to the joining of the first film surface and the second film surface, created by heating each film surface to at least their respective bonding initiation temperature.

“Blocking layer” herein refers to a film layer that can significantly delay the delivery of one or more gases (eg, O ₂ ).

"Anti-absorption layer" herein refers to a film layer that can resist friction, holes, and / or other potential causes of degradation of the package's complete state, and / or potential causes of package appearance deterioration.

"Knot layer" herein refers to a film layer capable of providing interlayer adhesion with adjacent layers comprising other non-adhesive or weakly-adhesive polymers.

"Bulk layer" herein refers to a film layer that can increase the misuse, toughness or elasticity of the film.

“Laminated” herein refers to bonding two or more film layers to each other using, for example, a polyurethane adhesive.

"Total Free Shrinkage" is a quantitative measurement performed according to ASTM D 2732 as described in this reference to the 1990 Annual Book of ASTM Standards, vol. 08.02, 368-371, the entire disclosure of which is incorporated herein. While shrinking at a specific test temperature of 85 ° C. (185 ° F.), means the percent dimensional change in a 10 cm × 10 cm specimen of the film. "Total free shrinkage" refers to the sum of free shrinkage in both the longitudinal and transverse directions.

"Machine direction" herein refers to the longitudinal direction of the film, ie the direction of the film formed during the extrusion and / or coating process.

"Landscape" herein refers to the direction across the film, ie, the direction perpendicular to the machine direction.

“Linear low density polyethylene” (LLDPE) herein refers to polyethylene produced by Ziegler / Natta catalysis and having a density of 0.917 to 0.925 g per cubic centimeter.

"Linear medium density polyethylene" (LMDPE) herein refers to polyethylene produced by Ziegler / Natta catalysis and having a density of 0.926 to 0.939 g per cubic centimeter.

The term "orientation ratio" (ie, the result of the degree to which the film is oriented in several directions, typically in 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 "drawing", while the orientation in the transverse direction is referred to as "drawing". In the case of a film extruded through an annular die, stretching is obtained by blowing the film to create bubbles. For such films, drawing is obtained by passing the film through two sets of powder nip rolls, where the downstream set has a higher surface speed than the upstream set, and the drawing ratio obtained is that of the upstream set of nip rolls. The surface velocity of the downstream set of nip rolls divided by the surface velocity.

All composition percentages used herein are expressed on a "weight" basis unless otherwise specified.

In-situ  polymerization

Since clay is a naturally occurring mineral, its composition can vary widely. The purity of the clay will affect the final composite properties. Many clays are aluminosilicates that have a sheet-like laminated structure and consist of silica SiO ₄ tetrahedra bonded to alumina AlO ₆ octahedrons in various ways. 2: 1 tetrahedra vs octahedrons produce smectite clay. The most common of the smectites is montmorillonite (bentonite). Other materials such as magnesium may replace aluminum in the crystal structure. These clays of magnesiosilicates are hectorite. Depending on the composition of the clay, the sheet or layer retains charge on the surface and on the edges. This charge is balanced by counter-ions located away from the interlaminar space of the clay. The thickness of the layer or platelet is approximately 1 nm and the side ratio ranges from 100 to 1500. The molecular weight of the plates [1.3X10 ⁸ ] is considerably higher than for most polymers. Moreover, the plates are not all rigid but have some degree of flexibility. In addition, the plates have a very high surface area, ie hundreds of square meters per gram. In addition, the plate may retain ion exchange capacity. Due to their charged nature, clays are generally highly hydrophilic species and therefore they cannot be used in combination with polymeric systems. Thus, an essential requirement to make clays compatible with polymers is to alter their polarity and make them lipophilic. This is accomplished by ion exchange of hydrophilic clays with organic cations such as alkylammonium ions. In montmorillonite, sodium ions in clay can be exchanged for amino acids such as 12-aminododecanoic acid [ADA].

Na ⁺ - Clay _{+ HO 2 CR-NH 3 +} Cl - → · HO 2 CR-NH 3 + - + NaCl clay

In addition to montmorillonite and hectorite, other synthetic clays, such as hydrotalcite, can be produced in a very pure form and retain a positive amount of plate charge.

The final nanocomposites can be interchelated or exfoliated.

In interchelated systems, organic polymers (PVdC) can be intercalated between clay layers so that the interlaminar space is increased but the layers still maintain a well-defined spatial relationship to each other.

In exfoliation, the plates are completely separated and the individual layers are distributed throughout the polymeric (PVdC) matrix.

By modifying the surface polarity of the clay, onium ions can allow thermodynamically favorable penetration of the polymer precursor into the interlayer region. The ability of onium ions to assist in the exfoliation of clays depends on their chemical properties such as their polarity. For clays charged in the same amount as hydrotalcite, onium salt modification is replaced by the use of ionic surfactants. Other types of clay modifications include ion-bipolar interactions, silane coupling agents, and the use of block copolymers and graft copolymers.

In the context of the present invention PVdC-nanoclay nanocomposites can be prepared by free radical suspension polymerization or free radical emulsion polymerization. The nanoclay slurry is predispersed in the aqueous layer with an appropriate suspending agent and the pH is adjusted to 6-8. This slurry is pumped into the polymerization reactor when the polymerization conversion has reached 20% or more. The reaction continues after addition of the nanoclay slurry until the conversion of the desired polymer is reached.

Another method that can be used is to add a nanoclay slurry to the reactor after the specific polymer conversion has been reached and the reaction has ended.

In both cases, if there is an increase in the viscosity of the system, adequate reaction agitation must be maintained or increased, and sufficient time must be allowed to achieve the desired exfoliation of the nanoclay.

Typical steps of suspension polymerization of PVdC can be carried out. These steps include the preparation of monomers such as vinylidene chloride (CH ₂ = CCl ₂ ) and vinyl chloride, and the use of water, initiators, suspending agents, antioxidants and the like. Monomer units may be derived from styrene, vinyl acetate, acrylonitrile, and C ₁ -C ₁₂ alkyl esters of (meth) acrylic acid (eg, methyl acrylate, butyl acrylate, methyl methacrylate, etc.). The preparation of PVdC (saram) is well known in the art. Preparation of the reactor includes purging with nitrogen, heating to the reaction temperature, stirring of a mixture of water, monomers and other additives at the desired rate. The reaction is then initiated and the reaction is carried out until a predetermined conversion.

After the reaction is complete, the unreacted monomer is removed from the polymer, washed, separated from water and dried. The dried nanocomposites are then formulated with appropriate processing additives and prepared in film form. Processing additives may be added to the reactor or later blended.

1 of the present specification shows a single layer film 10 having one layer 11.

Layer 11 comprises the polyvinylidene chloride laminated silicate nanocomposites of the present invention.

2 shows a two-layer film 20 having layers 21 and 22.

Layer 21 comprises the polyvinylidene chloride laminated silicate nanocomposite described above with respect to layer 11 in FIG. 1.

Layer 22 may be any suitable polymeric material such as, for example, an ethylenic polymer such as a thermoplastic polymer material, such as an ethylenic homopolymer or copolymer, an ethylene / alpha- such as a heterogeneous or homogeneous ethylene / alpha-olefin copolymer. Olefinic polymers such as olefin copolymers.

Layer 22 may be selected from olefinic polymers or copolymers such as ethylene / vinyl acetate copolymers; Ethylene / alkyl acrylate copolymers; Ethylene / (meth) acrylic acid copolymers; Inomers; Propylene homopolymers and copolymers; And butylene homopolymers and copolymers.

Blends of any of the materials disclosed herein with respect to layer 22 may be included in layer 22.

3 shows a three layer film 30 having a layer 31, a layer 32 and a layer 33.

Layer 31 comprises the polyvinylidene chloride laminated silicate nanocomposite described above with respect to layer 11 in FIG. 1.

Layer 32 and 33 may include any of the polymers described above with respect to layer 22 of FIG. 2.

Layer 32 and 33 may be the same or different. Differences in one or more physical properties, thicknesses, amounts or types of additives, degree of crosslinking or orientation, and the like may be present in the composition. For example, layer 32 may comprise ethylene vinyl acetate with 6% vinyl acetate, while layer 33 may comprise ethylene / vinyl acetate with 9% vinyl acetate. As another example, layer 32 may comprise ethylene / vinyl acetate with 6% vinyl acetate, while layer 33 may comprise ethylene / alpha-olefin copolymer. Therefore, the film structure according to the invention can be represented as A / B / A or A / B / C, where A, B and C each represent a separate layer of a multilayer film.

The multilayer film structure according to one embodiment of the invention has four or more layers. This film 40 (see FIG. 4) includes a sealing layer 43, a bulk layer 44, an O ₂ -blocking layer 41 comprising a polyvinylidene chloride laminated silicate nanocomposite, and an anti-fouling layer 42. This includes. Layer 43, layer 41 and layer 42 correspond to any of the layers 22, 32 and 33 of the figures described above in composition. Between the barrier layer 41, bulk layer 44 and the abuse prevention layer 42. Bulk layer 44 sealing layer 43 and the O ₂ - barrier layer 41 can be disposed between, O ₂ Can be arranged. If desired, a knot layer comprising a polymeric adhesive may be disposed between the sealing layer 43 and the bulk layer 44 and between the O ₂ -blocking layer 41 and the misuse layer 42.

Bulk layer 44 may include any of the materials described above with respect to layer 32 and layer 33 of FIG. 3.

As long as the film of the present invention provides the desired properties for the intended end use, the film of the present invention may have any total thickness desired. The thickness can be 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 6 mils, and 1.3 to 4 mils.

6 shows a conventional blister pack 50 for packaging a drug such as a tablet. Cover 52 is coupled to base 56 at shoulder 54 of base 56 (see also FIG. 5). A plurality of recesses 58, each designed to accommodate tablets, capsules or other medicines, are covered with a lid 52. Cover portion 52 is typically a metal or metallized foil. 5 shows a longitudinal cross section through the blister pack 50. Base 56 with recess 58 is in contact with lid 52 at shoulder 54. In the region of the shoulder 54, the lid 52 is connected to the base 56 by, for example, a suture or adhesive bond (sewing / gluing is not shown for the sake of brevity). FIG. 7 shows a cross section through a blister pack 50 having a base 56, a lid 52 and a recess 58.

8 shows an extended fragmentary cross sectional view of a blister pack 50 using the film of the present invention. Base 56 is composed of interior film 62 and exterior film 60.

Interior film 62 comprises the film of the present invention. The film 62 may be a disintegrated lay-flat film. This film can provide good (low) MVTR as well as low OTR for pharmaceutical use.

Interior film 60 may be any suitable film, such as any suitable film such as PVC (polyvinyl chloride) used in some blister packages.

Alternatively, the base may comprise a single film comprising the film of the present invention without requiring additional film 60.

As another alternative, the film of the present invention may comprise an exterior film and another film may form the interior film 62.

Those skilled in the art will appreciate that various combinations are possible as long as the film of the invention is present on the base.

In another embodiment, the film of the present invention may form the lid of the blister pack, and a conventional foil or plastic film may form the base.

Film 62 and film 60 may be bonded to each other by any suitable means such as lamination, coextrusion, extrusion coating, extrusion lamination, heat sealing, gluing, and the like.

The base of the blister pack of the present invention may be embossed, deeply drawn or vacuum molded.

In an embodiment, the lid can comprise an aluminum foil, an aluminum foil-containing laminate, or a plastic that exhibits low elasticity and weak stretchability.

The base may have 6 to 30 recesses in the form of a cup or saucer, for example. The recess is surrounded by a shoulder forming an interconnected plane. The base can be produced, for example, as an endless strip with the contents in the recess, and in particular can be joined with a cover in the form of a cover foil similar to the form of an endless strip. The cover part completely covers the base and is connected to the base at the shoulder, for example by sutures or adhesive bonds. The lid can be sutured or adhesively bonded to the shoulder over the entire area, but this closure or engagement can only be partially by selecting a particular closure means or bond pattern for this purpose. Next, the endless strip of the base covered with the lid can be cut to the desired size. This can be done for example using stamping means. At the same time, the blister pack may be of a given outer contour, or the blister pack may bend or create a flap section so as to provide a weak spot to the flap material or base to facilitate removal of the flap section and easy detachment of the contents. It can be provided.

The polyvinylidene chloride laminated silicate nanocomposites of the present invention may be prepared from any suitable vinylidene chloride-containing copolymer, ie, monomer units derived from vinylidene chloride (CH ₂ = CCl ₂ ) and at least one vinyl chloride, styrene, vinyl acetate. , Copolymers comprising monomeric units derived from acrylonitrile and C ₁ -C ₁₂ alkyl esters of (meth) acrylic acid (eg, methyl acrylate, butyl acrylate, methyl methacrylate, etc.). have. Thus, suitable PVdC resins include, for example, at least one vinylidene chloride / vinyl chloride copolymer, vinylidene chloride / methyl acrylate copolymer, vinylidene chloride / acrylonitrile copolymer, vinylidene chloride / butyl acrylate copolymer , Vinylidene chloride / styrene copolymer and vinylidene chloride / vinyl acetate copolymer. The weight percent of vinylidene chloride monomer is preferably 75 to 96% based on the weight of the copolymer excluding the nanosilicate content, and the weight percentage of the second monomer such as vinyl chloride is preferably air excluding the nanosilicate content. 4 to 25% by weight of the coalescing.

Stabilizers of the invention

1) Epoxidized compounds such as epichlorohydrin / bisphenol A, epoxidized soybean oil, epoxidized flaxseed oil, butyl esters of epoxidized flaxseed oil fatty acids, epoxidized octyl talate, epoxidized glycol diole Ate and the like and mixtures thereof;

2) oxidized polyethylene;

3) 2-ethyl hexyl diphenyl phosphate;

4) chlorinated polyethylene;

5) tetraethylene glycol di (2-ethylhexate);

6) metal salts of inorganic weak acids such as tetrasodium pyrophosphate;

7) fatty acid soaps such as calcium ricinoleate; And

8) Hydrotalcite such as magnesium aluminum hydroxycarbonate available from MITSUI ™ under the tradename DHT4A ™, or ALCAMIZER ™ 1 available from Kisuma Chemicals.

It may include one or more of.

Commercial examples of epoxidized compounds include epichlorohydrin / bisphenol A, an epoxy resin available as EPON ™ 828 from Shell; Epoxidized soybean oil available as VIKOFLEX ™ 7177 from Viking Chemical Company; Epoxidized flaxseed oil, available as VIKOFLEX ™ 7190 from Viking Chemical Company; Butyl esters of epoxidized linseed oil fatty acids available as VIKOFLEX ™ 9040 from Viking Chemical Company; Seed. blood. Epoxidized octyl talate available as MO-NOPLEX ™ S-73 from C. P. Hall Company; And seeds. blood. Epoxidized glycol dioleates available as MO-NOPLEX ™ S-75 from Hall Company.

Stabilizers are 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 parts based on the weight of the polyvinylidene chloride laminated silicate nanocomposite composition of the present invention, such as the poly The vinylidene chloride laminated silicate nanocomposite composition may be included in an amount of 1 to 3 parts, in particular 1.5 to 2 parts by weight.

Commercial examples of stabilizers include FERRO ™ PLASCHEK ™ 775, epoxidized soybean oil, and calcium ricinoleate available from Acme-Hardesty Company.

The polymeric processing aid of the present invention

1) fatty acid soaps such as calcium ricinoleate;

2) terpolymers with acrylate comonomers such as methyl methacrylate / butyl acrylate / styrene terpolymers; Methyl methacrylate / butyl acrylate / butyl methacrylate terpolymer; Or blends thereof;

3) n- (2-hydroxy) -12 hydroxy stearamide; And

4) Propylene Glycol Mono-ricinoleate

It may include one or more of.

The polymeric processing aid may be included in an amount of 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 parts based on the weight of the polyvinylidene chloride laminated silicate nanocomposite composition of the present invention. For example, the polymeric processing aid may be included in an amount of 0.5 to 5 parts, such as 1 to 3 parts, in particular 1.5 to 2 parts based on the weight of the polyvinylidene chloride laminated silicate nanocomposite composition of the present invention. .

A commercial example of a polymeric processing aid is ELF ATOCHEM ™ ME-TABLEN ™ L1000, an acrylic polymeric processing aid.

It will be appreciated that fatty acid soaps such as calcium ricinolate can act as both stabilizers and polymeric processing aids. In this embodiment, the fatty acid soap is 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 parts by weight of the polyvinylidene chloride laminated silicate nanocomposite composition of the present invention. It may be included as. For example, fatty acid soaps may be included in amounts of 0.5 to 5 parts, such as 1 to 3 parts, in particular 1.5 to 2 parts by weight of the polyvinylidene chloride laminated silicate nanocomposite composition of the present invention.

Other co-stabilized polymeric processing aids such as HENKEL ™ LOXIOL ™ VPG1732, a high molecular weight composite ester, and CASCHEM ™ CASTOWAX ™ NF, a hydrogenated castor oil, may optionally be included in the composition.

Nanosilicate of the present invention

1) octahedral clays such as montmorillonite, baydelite and nontronite, and

2) tetrahedral clays such as saponite, hectorite and souconite; And in particular the oxonium ion modified forms of these clays

And one or more clays of the phyllosilicate group, including one or more of them.

The nanosilicates of the present invention may be included in amounts of 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 parts by weight of the polyvinylidene chloride laminated silicate nanocomposite composition of the present invention. For example, the nanosilicates of the present invention may be included in amounts of 0.5 to 8 parts, such as 1 to 5 parts, in particular 1.5 to 4 parts by weight of the polyvinylidene chloride laminated silicate nanocomposite composition of the present invention. .

Commercial examples of nanosilicates include CLOISITE ™ 2OA and CLOISITE ™ 15A, an oxonium ion modified montmorillonite from Southern Clay Products; NANOMER ™ 1.31 PS, an oxonium ion modified montmorillonite from Nanocor; Bentonite clay (subclass of smectite) BENTONE ™ 107 and BENTONE ™ 111; Hectorite clays BENTONE ™ 108 and BENTONE ™ 16 (subclass of smectite, BENTONE ™ clays available from Elementis Specialties); Nanotalc, available from Nanoba LLC, having a Mg ₃ SiO ₁₀ (OH) ₂ composition; And nanotalcs (phyllosilicates) available from Argonne National Laboratory.

In some cases, the compositions and films of the present invention may include an antacid (hydrogen chloride). If present, the antacid may be included in an amount of 0.1 to 4 parts, such as 0.5 to 2 parts by weight of the polyvinylidene chloride laminated silicate nanocomposite composition of the present invention.

Commercial examples of antacids are MITSUI ™ DHT4A, a magnesium aluminum hydroxycarbonate of the formula Mg _{4 , 5} Al ₂ (OH) ₁₃ CO ₃ 3.5H ₂ O. An alternative material that can be used is tetrasodium pyrophosphate (TSPP).

The measurement of the overall thermal stability of the polyvinylidene chloride laminated silicate nanocomposite composition of the present invention can be performed by treating the composition between a pair of heated rollers or inside a heated mixing chamber. The time required to prepare a polymer that is significantly darkened due to shear degradation and temperature-induced degradation is a measure of the effect of thermal stability of the composition. Commercially acceptable vinylidene chloride copolymer blends exhibit thermal stability times of at least 10 minutes in a mixing device such as a BRA-BENDER ™ blender operating at about 168 ° C. (335 ° F.) and 63 revolutions per minute.

The compositions of the present invention can be extruded and processed by any of a number of methods known to those skilled in the art, for example, in US Pat. Nos. 3,741,253 (Brax et al.), 4,278,738 (Brax et al.) And 4,284,458. One layer of a film or multilayer film may be formed by the method disclosed in Schirmer, the entire disclosure of which is incorporated herein by this reference. Thus, as long as the method of the present invention utilizes the polyvinylidene chloride laminated silicate nanocomposite composition described above, the film according to the present invention can be prepared using any method suitable for producing a film having an oxygen barrier layer. Suitable methods include tubular cast coextrusion by techniques well known in the art, such as those disclosed in US Pat. No. 4,551,380 to Schenberg, the entire disclosure of which is incorporated herein by reference. Shaped or flat cast extrusion, or blown bubble extrusion (for single layer films) or coextrusion (for multilayer films). Multilayer films can be produced by coextrusion of all film layers, extrusion coating, extrusion lamination, corona bonding or conventional lamination. Methods of making multilayer films with PVdC layers are disclosed in US Pat. No. 4,112,181 (Baird, Jr. et al., Registered on September 5, 1978), the entire disclosure of which is incorporated herein by this reference. have. This patent describes a method of coextrusion of tubular films, in which the wall of the tube has three or more layers and the central layer is the PVdC layer. The tubular film is then biaxially oriented by the trapped bubble technique. The three layer film can be crosslinked by electron beam irradiation.

Suitable methods for the production of multilayer saran films are disclosed in US Pat. No. 3,741,253 (Brax et al., Registered June 26, 1973), the entire disclosure of which is incorporated herein by this reference. Discloses a multilayer biaxially oriented film having a PVdC blocking layer. The film expands by extrusion of a substrate layer or layers of polymer such as polyethylene or ethylene vinyl acetate copolymer into a crosslinked tube by irradiation. The layer of PVdC is extruded onto expanded tubing and another layer or layers of polymer are extruded simultaneously or sequentially onto PVdC. After cooling, this multilayer tubular structure is flattened and rounded off. The tube is then expanded and heated to its orientation temperature to orient the film biaxially. Bubbles cool rapidly and align. This process produces a heat shrinkable barrier film with low oxygen permeability. In addition, irradiation with the tendency to disintegrate Saran takes advantage of the crosslinked film without treating the PVdC layer. The blocking layer described in the examples of Brax et al. Is a plasticized copolymer composed of vinylidene chloride and vinyl chloride.

Films of the invention may be crosslinked, not crosslinked, oriented or unoriented, heat shrinkable or non-heat shrinkable. If the film is heat shrinkable, the film exhibits a total free shrinkage of 10 to 100% at 85 ° C. (185 ° F.). All or some films of the invention can be irradiated to induce crosslinking. In the course of the irradiation, the film is exposed to strong irradiation treatments, such as corona emission, plasma, flame, ultraviolet light, X-rays, gamma rays, beta rays and high energy electronic treatments, which induce crosslinking between molecules of the irradiated material. . Appropriate levels of irradiation can be determined by standard dosimetry methods known to those skilled in the art, and of course the exact amount of irradiation used depends on the specific film structure and its end use. The film can be irradiated at a level of 0.5-15 megarads (MR) (5 to 150 KGrays) such as 1-12 MR. More details on the investigation of polymeric films can be found, for example, in US Pat. Nos. 4,064,296 (Bornstein et al.), 4,120,716 (Bonet) and 4,879,430 (Hoffman). It is hereby incorporated by reference.

The film of the present invention can be produced by tubular coextrusion and extrusion coating. In the case of extrusion coating, the substrate is extruded or coextruded, optionally irradiated, and optionally stretched orientated; Thereafter, a layer of polyvinylidene chloride laminated silicate nanocomposite as disclosed herein is optionally coated with a substrate along with one or more additional layers.

The film of the present invention may have the following structure:

Wherein A is a polyvinylidene chloride laminated silicate nanocomposite; B, C, and D are any of the materials described above for each of layer 43, layer 44, and layer 42 of FIG. 4.

The polymeric components used to make the films according to the present invention may generally also contain appropriate amounts of other additives included in or blended with the composition. These include slip agents, antioxidants, fillers, pigments, pigments, radiation stabilizers, antistatic agents, elastomers, and other additives known to those skilled in the art of packaging films.

As long as the multilayer film of the present invention provides the desired properties for the specific packaging operation in which it is used, the multilayer film can have a layer with any total number desired and any total thickness desired.

Film layers comprising PVdC (polyvinylidene chloride laminated silicate nanocomposites) can be irradiated up to an irradiation level of 15MR without significant change (decomposition) of the film. However, chlorinated species are produced and cannot be approved by the FDA.

As is known to those skilled in the art, the use of polymers comprising units derived from vinylidene chloride and methyl acrylate reduces the degradation effect of irradiation on PVdC.

The film of the present invention can be laminated onto a substrate, adhesively attached, extrusion coated or extrusion laminated to form a laminate. Lamination can be accomplished by connecting the layers with adhesive, heat and pressure, and even spread coating and extrusion coating.

The films of the invention are particularly suitable for packaging applications where the product (s) being packaged must be protected from atmospheric O ₂ . More specifically, the films according to the invention are particularly useful as blisters for packaging drugs, films suitable for use as barrier bags, and films suitable for use in patch bags.

Blister packages can be prepared in conventional techniques and conventional packaging formats using the PVdC compositions described above and films made from the compositions.

It should also be recognized that "phr" means pounds per 100 (weight units) of material. Thus, for example, in the film of Comparative Example 1, a 100 pound equivalent of VDC / MA resin was blended with 2 pounds of ESO material and 2 pounds of polymeric processing aid. The equivalent of phr is "parts by weight". For example, VDC / MA is described separately from nanotalk (nanosilicate) to indicate the relative amounts of each material provided in the examples, but the nanosilicates in fact form part of the polyvinylidene chloride laminated silicate nanocomposite structure. Will understand.

Expect additional Example

Example  10

A four layer film having the following structure was coextruded in a hot blow process as an annular tube:

EVA ₁ / EVA ₂ / PVdC / EVA ₂

At this time,

EVA ₁ is EVA ₁₃ available from Huntsman as PE1335 ™ and having a vinyl acetate content of 3.3% by weight.

PVdC is a polyvinylidene chloride laminated silicate nanocomposite.

EVA ₂ is an EVA having a vinyl acetate content of 28% by weight available from DuPont as EL-VAX ™ 3182-2.

After extrusion, the tubular coextruded itself disintegrates to form a release film having the following structure:

EVA ₁ / EVA ₂ / PVdC / EVA ₂ // EVA ₂ / PVdC / EVA ₂ / EVA ₁

The preferred thickness for each PVdC layer is 0.75 mils.

Example  11

Four-layer films similar to the four-layer films of the above examples were prepared by a cast coextrusion process, with the outer EVA ₁ layer replaced by LLDPE. Thus, the film has the following structure:

LLDPE / EVA ₂ / PVdC / EVA ₂

Two commercial LLDPE resins, each useful in this example, were DOWLEX 2045.03 and DOWLEX 2045.04, respectively available from Dow. Each of these is an ethylene / octane-1 copolymer having an octane content of 6.5% by weight and a density of 0.920 g / cc.

Claims (20)

a) 100 parts polyvinylidene chloride layered silicate nanocomposite based on the weight of the composition; b) 0.1 to 10 parts stabilizer based on the weight of the composition; And c) at least one layer comprising a polyvinylidene chloride laminated silicate nanocomposite composition comprising 0.1 to 10 parts of a polymeric processing aid by weight of the composition. The method of claim 1, Stabilizers include a) epoxidized compounds; b) oxidized polyethylene; c) 2-ethyl hexyl diphenyl phosphate; d) chlorinated polyethylene; e) tetraethylene glycol di (2-ethylhexate); f) metal salts of inorganic weak acids; And g) hydrotalcite. The method of claim 2, The epoxidized compound consists of epichlorohydrin / bisphenol A, epoxidized soybean oil, epoxidized flaxseed oil, butyl ester of epoxidized flaxseed oil fatty acid, epoxidized octyl talate and epoxidized glycol dioleate A film selected from the group. The method of claim 1, The polymeric processing aid is a) terpolymer having an acrylate comonomer; b) n- (2-hydroxyethyl) -12 hydroxy stearamide; And c) propylene glycol mono-ricinoleate. The method of claim 4, wherein Terpolymers with acrylate comonomers include methyl methacrylate / butyl acrylate / styrene terpolymers; And methyl methacrylate / butyl acrylate / butyl methacrylate terpolymer. The method of claim 1, The polyvinylidene chloride laminated silicate nanocomposite comprises a hydrophilic clay of the phyllosilicate group, the clay comprising a) dioctahedral clay; And b) trioctahedral clay. The method of claim 6, Wherein the hydrophilic clay is selected from the group consisting of montmorillonite, beidelite and nontronite. The method of claim 6, A film, wherein the hydrophilic clay is modified with oxonium ions. The method of claim 1, A film, wherein the composition comprises an acid scavenger. a) 100 parts polyvinylidene chloride laminated silicate nanocomposite based on the weight of the composition; And b) at least one layer comprising a polyvinylidene chloride laminated silicate nanocomposite composition comprising 0.1 to 10 parts fatty acid soap by weight of the composition. The method of claim 10, A film, wherein the fatty acid soap comprises calcium ricinoleate. The method of claim 10, The polyvinylidene chloride laminated silicate nanocomposite comprises a hydrophilic clay of the phyllosilicate group, wherein the clay is a) octahedral clay; And b) trioctahedral clay. The method of claim 12, And the hydrophilic clay is selected from the group consisting of montmorillonite, bedelite and nontronite. The method of claim 12, A film, wherein the hydrophilic clay is modified with oxonium ions. The method of claim 10, A film, wherein the composition comprises an antacid. a) a base comprising i) a plurality of recesses and ii) a shoulder surrounding the recess; b) a lid attached to the shoulder; And c) the contents disposed within each recess. Wherein at least one of the base and the lid comprises: i) 100 parts polyvinylidene chloride laminated silicate nanocomposite based on the weight of the composition; ii) 0.1 to 10 parts of a stabilizer based on the weight of the composition; And iii) a polyvinylidene chloride laminated silicate nanocomposite composition comprising 0.1 to 10 parts of a polymeric processing aid by weight of the composition. The method of claim 16, Stabilizers include a) epoxidized compounds; b) oxidized polyethylene; c) 2-ethyl hexyl diphenyl phosphate; d) chlorinated polyethylene; e) tetraethylene glycol di (2-ethylhexate); f) metal salts of inorganic weak acids; And g) a blister pack selected from the group consisting of hydrotalcites. The method of claim 16, The polymeric processing aid is a) terpolymer having an acrylate comonomer; b) n- (2-hydroxyethyl) -12 hydroxy stearamide; And c) a blister pack selected from the group consisting of propylene glycol mono-ricinoleate. The method of claim 16, The polyvinylidene chloride laminated silicate nanocomposite comprises a hydrophilic clay of the smectite group, wherein the clay is a) octahedral clay; And b) a trihedral clay. a) a base comprising i) a plurality of recesses and ii) a shoulder surrounding the recess; b) a cover portion attached to the shoulder; And c) the contents disposed within each recess. Wherein at least one of the base and the lid comprises: i) 100 parts polyvinylidene chloride laminated silicate nanocomposite based on the weight of the composition; And ii) a polyvinylidene chloride laminated silicate nanocomposite composition comprising 0.1 to 10 parts fatty acid soap by weight of the composition.

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