METHODS FOR REDUCING NOISE ASSOCIATED WITH FILMS CONTAINING ODOR BARRIER

COMPONENTS

Cross Reference to Related Application

[0001] This application claims priority upon US provisional application Serial No. 61/426,909 filed on December 23, 2010.

Field of the Invention

[0002] The present invention relates to polymeric barrier films containing noise suppressing agents, and articles comprising such films. The invention also relates to methods for reducing the amount of noise associated with polymeric barrier films. The films, articles, and methods associated therewith are useful in various fields such as medical and health care applications.

Background of the Invention

[0003] Numerous applications are known in which a gas and vapor barrier film is incorporated in articles to prevent the transmission of gases and vapors to thereby control or prevent the loss of freshness and flavor and/or the escape of aroma or odor. In some applications, including medical and health care applications, it is desirable that the barrier film be relatively quiet and not emit noise upon deflecting or otherwise moving the film. For example, this is a prime objective for materials used in ostomy pouches or similar products worn under a person's clothing. [0004] In an attempt to provide films with high barrier properties with low noise characteristics, artisans have used polyvinylidene chloride or SA AN™-coated films. However, those materials contain chlorine and thus are difficult and/or costly to recycle. Furthermore, films that contain polyvinylidene chloride can not be incinerated without generating toxic gas. Accordingly, it would be desirable to provide a halogen-free film that exhibited high barrier and low noise properties, to provide a suitable replacement for currently known halogen containing films such as the noted chlorine containing materials.

Summary of the Invention

[0005] The difficulties and drawbacks associated with previously known barrier films and products using such films are addressed in the present compositions, films, and methods.

[0006] In one aspect, the present invention provides a polymeric composition exhibiting low noise properties. The composition comprises at least one polymer, and an effective amount of a noise suppressant having (i) a viscosity of from about 25 cps to about 2800 cps at 25°C, (ii) a glass transition temperature of from about -95°C to about -72°C, (iii) a density of from about 0.81 g/cm ³ to about 0.85 g/cm ³ at 23°C, (iv) a flash point of from about 225°C to about 290°C, and (v) a molecular weight of from about 450 to about 3,000.

[0007] In another aspect, the present invention also provides a polymeric barrier film exhibiting low noise properties. The film comprises at least one polymer, and an effective amount of a noise suppressant having (i) a viscosity of from about 25 cps to about 2800 cps at 25°C, (ii) a glass transition temperature of from about -95°C to about -72°C, (iii) a density of from about 0.81 g/cm ³ to about 0.85 g/cm ³ at 23°C, (iv) a flash point of from about 225°C to about 290°C, and (v) a molecular weight of from about 450 to about 3,000. [0008] In yet another aspect, the invention provides a multilayer barrier assembly comprising at least one functional layer, and a low noise barrier layer. The low noise barrier layer includes at least one polymer, and an effective amount of a noise suppressant having (i) a viscosity of from about 25 cps to about 2800 cps at 25°C, (ii) a glass transition temperature of from about -95°C to about -72°C, (iii) a density of from about 0.81 g/cm ³ to about 0.85 g/cm ³ at 23°C, (iv) a flash point of from about 225°C to about 290°C, and (v) a molecular weight of from about 450 to about 3,000.

[0009] In still another aspect, the present invention provides a method for reducing noise associated with a polymeric barrier film. The method comprises providing a polymeric barrier composition and forming a film from the polymeric barrier composition, and prior to film forming, adding an effective amount of at least one noise suppressant to the polymeric barrier composition. The noise suppressant has (i) a viscosity of from about 25 cps to about 2800 cps at 25°C, (ii) a glass transition temperature of from about -95°C to about -72°C, (iii) a density of from about 0.81 g/cm ³ to about 0.85 g/cm ³ at 23°C, (iv) a flash point of from about 225°C to about 290°C, and (v) a molecular weight of from about 450 to about 3,000.

[0010] In another aspect, the present invention provides a multilayer barrier film comprising an outer nonwoven layer, a first flexible support for dampening noise, a first moisture and odor barrier layer, a layer for reducing transmission of oxygen and odor, a second moisture and odor barrier layer, a second flexible support for dampening noise, and an inner antimicrobial layer.

[0011] In still another aspect, the present invention provides a multilayer barrier comprising G- EVOH and a norbornene-based component. G-EVOH is also known as G-Polymer in the relevant field(s) of art.

[0012] As will be realized, the invention is capable of other and different embodiments and its several details are capable of modifications in various respects, all without departing from the invention. Accordingly, the drawings and description are to be regarded as illustrative and not restrictive. Brief Description of the Drawings

[0013] Figure 1 is a schematic perspective view of a preferred embodiment polymeric film according to the present invention.

[0014] Figure 2 is a schematic cross sectional view of a preferred embodiment multilayer assembly including the preferred film depicted in Figure 1.

Detailed Description of the Embodiments

[0015] Generally, in accordance with the present invention, various materials have been identified that can serve as noise suppressants when added to a polymeric barrier composition. The polymeric barrier composition can be coextruded to form a polymeric barrier film having reduced noise properties. When formed into a film or similar shape, the film is relatively quiet when deflected or subjected to bending or other distortion. The film or layer can be incorporated into a wide range of articles and preferably used in a multilayer barrier assembly.

[0016] The barrier films and/or multilayer barrier assemblies are preferably halogen-free and are particularly well suited for medical applications such as in forming ostomy pouches. Since the films and multilayer assemblies are halogen-free and particularly free of chlorine, they can be recycled and/or subjected to a wide array of material reclamation operations. These aspects and others are all described in greater detail as follows.

Polymeric Barrier Film

[0017] Typical barrier films use water vapor transmission rate (WVTR) and oxygen transmission rate (OTR) to characterize their barrier properties. Materials known to have good barrier properties against water and oxygen permeation have a high modulus, and thereby are "noisy". A goal of the present invention is to prevent the passage of hydrogen sulfide and other malodorous molecules. The solution may not require the same approach needed for achieving low WVT and OTR. As explained in greater detail herein, the preferred embodiments relate to reducing unwanted noise associated with barrier films.

[0018] In a preferred embodiment of the present invention a polymeric barrier film is provided which comprises at least one thermoplastic polymer, and at least one noise suppressing agent. The thermoplastic polymer comprises a polyolefin and preferably a cyclic polyolefin copolymer, a polyester, a polyamide, a styrene-based homopolymer or copolymer, a polycarbonate, a polyurethane, a halogen- containing polymer, an acrylate-based or methacrylate-based homopolymer or copolymer, an alkene- unsaturated carboxylic acid or unsaturated carboxylic acid derivative copolymer, a vinyl alcohol- containing homopolymer or copolymer, or a mixture of two or more of any of the foregoing polymers. In certain embodiments of the invention, the thermoplastic polymer comprises a polyethylene, an alkene-unsaturated carboxylic acid or unsaturated carboxylic acid derivative copolymer, or a mixture of two or more of any of the foregoing polymers. Preferably, the polyethylene comprises a high density polyethylene, a medium density polyethylene, a low density polyethylene, a linear low density polyethylene, a very low density polyethylene, a polyethylene plastomer, or a mixture of two or more of any of the foregoing polyethylenes. It is also contemplated to use polypropylene in any of its grades such as high molecular weight polypropylene. The alkene-unsaturated carboxylic acid or unsaturated carboxylic acid derivative copolymer is also preferably heat sealable and comprises an ethylene vinyl acetate copolymer, an ethylene-methacrylic acid copolymer, an ethylene-acrylic acid copolymer, an ethylene-alkyl methacrylate copolymer, an ethylene-alkyl acrylate copolymer, an ionomer to include metal salts of ethylene-methacrylic acid copolymers, or a mixture of two or more of any of the foregoing copolymers. [0019] In certain embodiments, it is preferred to utilize one or more cyclic olefin copolymers in the polymeric barrier film. Cyclic olefin copolymers are also known as ethylene copolymer, COC, cyclo olefinecopolymer, cyclic olefin polymer, and ethylene-norbornene copolymer. It is contemplated that in certain embodiments, various norbornene-based materials may be used instead of or in addition to the COC's, as described in greater detail herein. And, in particular embodiments, an elastomeric COC is used.

[0020] Presently, there exist several types of commercially available cyclic olefin copolymers based on different types of cyclic monomers and polymerization methods. Cyclic olefin copolymers are typically produced by chain copolymerization of cyclic monomers such as 8,9,10-trinorborn-2-ene (norbornene) or l,2,3,4,4a,5,8,8a-octahydro-l,4:5,8-dimethanonaphthalene (tetracyclododecene) with ethene. Non-limiting examples of commercially available cyclic olefin copolymers include those available from TOPAS Advanced Polymers under the designation TOPAS, Mitsui Chemical's APEL, or those formed by ring-opening metathesis polymerization of various cyclic monomers followed by hydrogenation, which are available from Japan Synthetic Rubber under the designation ARTON, and Zeon Chemical's ZEONEX and ZEONOR.

[0021] Particularly preferred cyclic olefin copolymers are those available from TOPAS Advanced Polymers. These cyclic olefin copolymers, in contrast to the partially crystalline polyolefins polyethylene and polypropylene, are generally amorphous, transparent copolymers based on cyclic olefins and linear olefins.

[0022] Most preferably, the cyclic olefin copolymers from TOPAS are grades 9506 and 8007. Another preferred cyclic olefin copolymer from TOPAS is also noted below. This cyclic olefin copolymer is referred to as a developmental polymer. The developmental polymer is sometimes referred to as E- 140 by TOPAS. The properties and characteristics of these copolymers are set forth below in Tables 1-3. Table 1 - Grade 9506 From TOPAS

Table 2 - Grade 8007F-04 From TOPAS

Table 3 - Developmental Cyclic Olefin Copolymer From TOPAS

Property Value Unit Test Standard

Physical Properties

Density 0.940 g/cm ³ ISO 1183

Melt volume rate (MVR) at 190°C and 2.16 kg 3.0 cm ³ /10 min ISO 1133

Melt volume rate (MVR) at 260°C and 2.16 kg 12.0 cm ³ /10 min ISO 1133

Hardness, shore A 89 - ISO 868

WVTR (23°C / 85% RH) 1.0 g*100μm/m ² *day ISO 15106-3

WVTR (38°C / 90% RH) 4.6 g*nx^m/m ² *day ISO 15106-3

OTR (23°C / 50% RH) 1060 α:*100μιτι/ιτι ² *day ISO 15105-2

Mechanical Properties

Tensile stress at break (50mm/min) >19 MPa ISO 527-T2/1A

Tensile modulus (lmm/min) 44 MPa ISO 527-T2/1A

Tensile strain at break (50mm/min) >450 % ISO 527-T2/1A

Compression set (24hr / 23°C) 35 % ISO 815

Compression set (72hr / 23°C) 32 % ISO 815

Compression set (24hr / 60°C) 90 % ISO 815

Tear strength 47 kN/m ISO 34-1

Puncture resistance 44 J ASTM D3786-08

Film Properties - 50 μιτι / 2 mil cast film

Tensile stress at break (machine direction) 8.8 ksi ASTM D882

Tensile modulus (MD) 5.26 ksi ASTM D882

Elongation at break (MD) 640 % ASTM D882

Tensile stress at break (transverse direction) 7.31 ksi ASTM D882

Tensile modulus (TD) 4.93 ksi ASTM D882

Elongation at break (TD) 620 % ASTM D882

Elmendorf tear (MD, 3200 grams) 1103 grams ASTM D1922

Elmendorf tear (TD, 3200 grams) 1221 grams ASTM D1922

Haze 1.5 % ASTM D1003

Gloss (60 °C) 94 % ASTM D2457

Electrical Properties

Relative permittivity at 1 GHz 2.24 - ASTM D2520 / B

Dissipation factor at 1 GHz 2.6E-04 - ASTM D2520 / B

Dielectric strength 4000 V/mil ASTM D149-97a

Thermal Properties

Ductile-brittle temperature <-90 °C ISO 974

Tm - melt temperature 84 °C Internal method

Vicat softening temperature, VST/A50 64 °C ISO 306 [0023] For certain applications, it may be preferred to utilize a COC having elastomeric properties. As will be appreciated, elastomers exhibit a property of viscoelasticity or as commonly referred elasticity. Elastomers typically have a relatively low Young's modulus and a high yield strain as compared to most other materials. It is contemplated that an elastomeric COC available from TOPAS could be used in the various embodiments described herein. Reported information for the elastomeric COC from TOPAS indicates that the COC elastomers have a tensile modulus of about 4,412 N/cm ² and elongation at break greater than 450 %. In addition, the elastomeric COC exhibits relatively low dielectric properties comparable to certain fluoroelastomers, thereby providing excellent electrical insulation performance. Furthermore, the material is reported to maintain ductility at temperatures below 80 C. The noted elastomeric COC also reportedly exhibits a Shore A hardness of 89.

[0024] In certain other embodiments, it is preferred to utilize a combination of ethylene vinyl alcohol (EVOH) and ionomer in the polymeric barrier film. Ethylene vinyl alcohol, commonly abbreviated EVOH, is a formal copolymer of ethylene and vinyl alcohol. Because the latter monomer mainly exists as its tautomer acetaldehyde, the copolymer is prepared by polymerization of ethylene and vinyl acetate to produce the ethylene vinyl acetate (EVA) copolymer followed by hydrolysis. EVOH is typically used to provide barrier properties, primarily as an oxygen barrier for improved food packaging shelf life and as a hydrocarbon barrier for fuel tanks. EVOH is typically coextruded or laminated as a thin layer between cardboard, foil, or other plastics. EVOH copolymer is traditionally defined by the mole percent ethylene content. Lower ethylene content grades have higher barrier properties, and higher ethylene content grades have lower temperatures for extrusion.

[0025] The preferred barrier film containing EVOH also preferably comprises one or more ionomers. An ionomer is an ion containing copolymer, lonomers contain both nonionic repeat units, and up to about 15% of ion containing repeat units. The preferred embodiment films can utilize a wide array of ionomers. However, a zinc ionomer is preferred. [0026] Figure 1 illustrates a preferred embodiment barrier film 2 defining an outer face 4. The film 2 can be provided in sheet form, roll form, or in a shaped or contoured configuration as desired. The film 2 includes one or more polymers and one or more noise suppressants as described herein.

Noise Suppressing Agents

[0027] Preferred noise suppressants for incorporation into a barrier film include various plasticizers and/or polymer modifiers. Non-limiting examples of a preferred noise suppressing agent are certain non-phthalate hydrocarbon fluids having a viscosity of from about 25 to about 2800 cps at 25°C, having an extremely low glass transition temperature, which are noncrystalline, and which are generally compatible with polyolefins. Non-limiting examples of such fluids are synthetic alpha olefinic oils commercially available under the designations ELEVAST™ or SPECT ASYN™ from ExxonMobil. Generally, the preferred noise suppressant has a glass transition temperature of from about -95°C to about -72°C; a density of from about 0.81 g/cm ³ to about 0.85 g/cm ³ at 23°C; a flash point (Cleveland Open Cup, COC) of from about 225°C to about 290°C; and a molecular weight of from about 450 to about 3,000. As will be appreciated, these properties of the preferred noise suppressant(s) are of the noise suppressant prior to incorporation into the polymeric material forming the film.

[0028] Representative examples of such commercially available materials that can be used as noise suppressants in the present invention include the ELEVAST™ materials and specifically grades A30, A50, A70, A80, C30, C70, E10, E20, R120, R130, R150, R170, and combinations thereof. These materials are believed to be compounds comprising carbon and hydrogen and which are generally free from functional groups selected from hydroxide, aryls and substituted aryls, halogens, alkoxys, carboxylates, esters, acrylates, oxygen, nitrogen, and carboxyl.

[0029] Additional examples of materials that may serve as suitable noise suppressants as described herein include but are not limited to mineral oils and peroxide materials. [0030] The noise suppressant agent can be used at nearly any concentration in the polymeric film which results in noise reduction. These concentrations are referred to herein as "effective amounts." Preferably, concentrations of the noted materials available under the ELEVAST™ designation range from about 1% to about 3% by weight.

[0031] When using the previously noted ELEVAST™ materials as the noise suppressants as described herein, it has been found particularly beneficial to use such materials in combination with cyclic olefin copolymers. It has also been found preferable to use the ELEVAST™ agents as noise suppressants in combination with ethylene vinyl alcohol (EVOH) and ionomer. These aspects are described in greater detail herein.

[0032] Although not wishing to be bound to any particular theory, it is believed that use of certain polymer additives which reduce the modulus of the composition, also serve to reduce the noise associated with films formed from the composition. As far as is known, many if not all prior attempts by formulators to reduce noise were accompanied by a loss of barrier function in the resulting film. The preferred embodiment compositions and films described herein exhibit a unique and surprising combination of properties in that the films exhibit high barrier properties while also being relatively quieter. In a most preferred aspect, the compositions and films are also free of halogens such as chlorine.

[0033] The ELEVAST™ agents are commercially noted as modulus reducing agents for amorphous polymers. However, it has been discovered that certain ELEVAST™ agents do not function as modulus reducers in all amorphous polymers. Moreover, as far as is known, ELEVAST™ agents are not typically used for crystalline polymer systems. Thus in accordance with the invention, a new strategy is provided for incorporating an ELEVAST™ or similar agent into a crystalline or partially crystalline polymeric system whereby a reduction in modulus is achieved. The strategy involves blending or otherwise combining the ELEVAST™ agent(s) with an amorphous polymer such as metallocene-catalyzed linear low density polyethylene (LLDPE). The blend of ELEVAST™ and amorphous polymer is then incorporated into the crystalline or partially crystalline polymeric system.

Other Functional Layer(s)

[0034] In addition to the low noise barrier layer, the preferred embodiment multilayer barrier assemblies may also comprise additional functional layers. Preferably, the functional layers are all free of halogens. Non-limiting examples of suitable functional layers include outer protective layers, support layers, supplemental or secondary barrier layers, antimicrobial layers, and inner layers.

Multilayer Barrier

[0035] The present invention also provides multilayer films for use in medical applications and in particular, for ostomy applications. As will be appreciated, an important characteristic for such films is preventing or at least significantly reducing transmission of odors through the film. Another important characteristic for such films is that the films be relatively quiet and not emit excessive noise upon deflecting or movement of the film. The preferred films feature a polymeric barrier layer comprising one or more noise suppressing agents. The agents are as previously described herein. A preferred multilayer barrier construction uses one or more barrier layers that include a cyclic olefin copolymer (COC) and optionally in combination with a compatibilizer. Another preferred multilayer barrier construction includes one or more barrier layers that include ethylene vinyl alcohol in combination with ionomer. In other embodiments, the preferred multilayer barrier construction includes an inner layer containing nanoclay particles. The nanoclay particles are preferably incorporated into a barrier layer.

[0036] Figure 2 is a schematic illustration of a preferred multilayer barrier assembly 8 in accordance with the present invention. The multilayer assembly 8 comprises an outer layer 10 defining an outer face 12, a first flexible support layer 20, a first moisture and odor barrier layer(s) 30, a secondary barrier 40 for reducing transmission of oxygen and odors, a second moisture and odor barrier 50, a second flexible support layer 60, and an inner antimicrobial layer 70 defining an inner face 72 for contacting a microbe containing medium.

[0037] Various preferred film constructions are set forth in Tables 4A-4D below. One or more noise suppressants may optionally be included in at least one of the layers for moisture and odor barrier control and the layer for reducing transmission of oxygen and hydrogen sulfide. The percentages shown in Tables 4A-4D do not include addition of the noise suppressant(s).

[0038] Referring to Table 4A, generally, the preferred embodiment multilayer constructions include (the layers are noted in order from the outermost layer to the innermost layer): (4Ai) an outer nonwoven layer, (4Aii) a first flexible support for dampening noise, preferably using an elastomer of polyethylene and polypropylene, (4Aiii) a first moisture and odor barrier layer or layer assembly including the COC and a compatibilizer, g-maleic anhydride EVA, (4Aiv) another barrier for reducing transmission of oxygen and hydrogen sulfide (i.e. odor) that includes EVOH and a nanoclay component to provide a tortuous path to further reduce the potential for transfer of chemical agents or species across the barrier, (4Av) a second moisture and odor barrier corresponding to previously noted layer (4Aiii), (4Avi) a second flexible support corresponding to previously noted layer (4Aii), and (4Avii) an inner antimicrobial layer containing an antimicrobial agent such as a silver ion containing compound. Preferably, the layer(s) (4Ai)-(4Avii) are arranged in order and each layer is disposed immediately adjacent to one or more sequentially positioned layer(s). For example, layer (4Aiii) is preferably disposed immediately adjacent and between layers (4Aii) and (4Aiv). However, it will be appreciated that the invention includes other multilayer assemblies using different arrangements and combinations of layers. The preferred embodiment noise suppressant agents are preferably incorporated in one or more of layers (4Aiii), (4Aiv), (4Av), and combinations thereof. Table 4A - Preferred Multilayer Film

[0039] Referring further to Table 4A, the outer nonwoven layer (4Ai) preferably includes a sublayer indicated by the reference to 18% vinyl acetate (VA). This sublayer is provided for receiving attachments to the multilayer film.

[0040] Referring to Table 4B, that preferred embodiment multilayer construction includes: (4Bi) an outer nonwoven layer, (4Bii) a first flexible support for dampening noise, preferably using an elastomer of polyethylene and polypropylene, (4Biii) a first moisture and odor barrier layer including the COC and preferably an elastomeric COC which is exclusively used in this layer, (4Biv) a first tie layer, (4Bv) another barrier for reducing transmission of oxygen and odor such as hydrogen sulfide using G-EVOH, (4Bvi) a second tie layer, (4Bvii) a second moisture and odor barrier layer as previously described, (4Bviii) a second flexible support as previously described, and (4Bix) an inner antimicrobial layer. Table 4B - Preferred Multilayer Film

[0041] Referring to Table 4C, that preferred embodiment multilayer construction includes (4Ci) an outer nonwoven layer, (4Cii) a first flexible support for dampening noise, preferably using an elastomer of polyethylene and polypropylene, (4Ciii) a first moisture and odor barrier layer or layer assembly including an elastomeric COC in conjunction with a tie component, (4Civ) another barrier for reducing transmission of oxygen and odor such as hydrogen sulfide that includes G-EVOH and a zinc ionomer, (4Cv) a second moisture and odor barrier layer as previously described, (4Cvi) a second flexible support as previously described, and (4Cvii) an inner antimicrobial layer.

Table 4C- Preferred Multilayer Film

[0042] Referring to Table 4D, that preferred embodiment multilayer construction includes: (4Di) an outer nonwoven layer, (4Dii) a first flexible support and barrier layer for dampening noise and reducing transmission of moisture and odor, preferably using an elastomer of polyethylene and polypropylene, in combination with an elastomeric COC, (4Diii) a first tie layer, (4Div) another barrier layer for reducing transmission of oxygen and odor such as hydrogen sulfide that includes G-EVOH and a zinc ionomer, (4Dv) a second tie layer, (4Dvi) a second flexible support and barrier layer for dampening noise and reducing transmission of moisture and odor, as previously described, and (4Dvii) an inner antimicrobial layer. Table 4D- Preferred Multilayer Film

[0043] In the previously described multilayer embodiments summarized in Tables 4A-4D, it will be appreciated that it is generally preferred to combine the COC with the tie resin, e.g. GMAH-EVA, or the polyolefin elastomer. Most preferably, the COC and the polyolefin elastomer are utilized in the same layer, as in the embodiment of Table 4D. Furthermore, the present invention includes multilayer embodiments in which agents providing the function of reducing transmission of moisture and/or odor are combined with and used in the same layer as agents providing a noise dampening function. This is represented in the construction noted in Table 4D.

[0044] The COC preferred for use in the multilayer film constructions is obtained from TOPAS Advanced Polymers. The COC is believed to be a copolymer of norbornene and ethylene. At present, the previously noted developmental cyclic olefin copolymer from TOPAS is preferred for use in the various multilayer barrier constructions. It is also contemplated that Grade 8007 and/or Grade 9506 from TOPAS may be used. The properties and characteristics of these copolymers are set forth in Tables 1-3 herein. The COC can be used in the moisture or odor barrier layer in nearly any concentration, such as from about 10% to about 100%, more preferably from about 14% to about 100%, more preferably from about 50% to about 90%, more preferably from about 60% to about 80%, and most preferably about 70%. Although not wishing to be bound to any particular proportions, when using an elastomeric COC, it is preferred that the elastomeric COC constitute from about 10% to about 15% of the total weight of the multilayer barrier. In certain embodiments, it is preferred to use the COC in combination with a tie component such as g-maleic anhydride ethylene vinyl acetate (GMAH-EVA). It will be appreciated that the various multilayer barrier films are not limited to the use of these particular COC's. Instead, it is contemplated that a wide range of comparable compounds and/or materials could be utilized in the noted moisture and odor barrier layer(s) of the multilayer construction. As previously noted, in certain embodiments, it may be preferred to include one or more noise suppressants in the layer(s) containing the COC's.

[0045] The barrier for reducing transmission of oxygen and odor such as hydrogen sulfide, preferably comprises EVOH, one or more optional nanoclay components and an ionomer component. The EVOH is incorporated at nearly any effective concentration, however typical concentrations range from about 40% to about 100%, preferably from about 50% to about 80%, and most preferably from about 60% to about 70%. For certain applications, it is contemplated that G-EVOH be used and preferably a particular grade of ethylene vinyl alcohol copolymer commercially available under the designation G-SOARNOL from Nippon Gohsei of Osaka, Japan can be used. As compared to conventional EVOH, G-SOARNOL polymers exhibit relatively low crystallinity and low melting point, and relatively high transparency, orientability, and shrinkability. The G-SOARNOL polymer system exhibits increased barrier properties as compared to conventional EVOH. Although not wishing to be bound to any particular theory, it is believed that G-SOARNOL is commercially available from Nippon under the designations SG634B and SG654B. These materials are believed to be copolymers of EVOH and polyvinyl alcohol (PVA). The SG654B material is reported to exhibit a melt flow rate of 3.5 g/10 min (ISOI 130, 230 C, 2.16 kg). The use of G-SOA NOL imparts to the resulting layer a higher gas barrier at a lower modulus. Essentially, the G-SOARNOL performs as a high ethylene content EVOH while maintaining the functionality associated with a low ethylene content EVOH. As previously noted, G-EVOH is also known as G-Polymer. The optional nanoclay component includes nano-sized clay particulates that upon suitable incorporation throughout the layer, provide a tortuous path for molecules and chemical species migrating through the layer. A preferred and non-limiting example of such a nanoclay component is NANOBIOTER ^* available from Nanobiomatters Industries of Spain. It will be appreciated however that a wide array of nanoclay containing additives could be used. The concentration of the nanoclay component is generally any effective concentration, however typically such concentration is from about 15% to about 55%, preferably from about 25% to about 45% and most preferably from about 30% to about 40%. The ionomer component is preferably a zinc neutralized ionomer or as periodically referred to herein, a zinc ionomer. The ionomer can be used at any effective concentration, however typically such concentrations range from about 5% to about 40%, preferably from about 10% to about 30%, and most preferably from about 15% to about 20%. As previously noted, in certain embodiments, it may be preferred to include one or more noise suppressants in the layer(s) containing EVOH, optional nanoclay component, and/or ionomer.

[0046] It is also contemplated that the odor barrier layer may comprise one or more cyclic olefin copolymers instead of or in addition to EVOH and/or ionomer. In certain embodiments, it may be preferred to provide an odor blocking layer that comprises one or more cyclic olefin copolymers. Although not wishing to be bound to any particular theory, it is believed that upon incorporation of a cyclic olefin copolymer, the shape of the norbornene rings in the polymeric matrix tend to trap or block odor producing molecules and/or chemical species. The use of one or more cyclic olefin copolymers in an odor barrier layer may be particularly desirable if water vapor transmission rate (WVTR) is not a concern for that layer. Tables 5A and 5B set forth below compare the performance of various layers based upon polyethylene or polypropylene, with or without a cyclic olefin copolymer (COC). The COC used in the films noted in Table 5A, is a developmental COC from TOPAS summarized in Table 3. The films were compared against a conventional thermoplastic heat shrink wrapping film typically used in packaging and available under the designation C YOVAC™.

Table 5A - Comparison of Odor Blocking Performance

Table 5B - Comparison of Odor Blocking Performance with Aging

[0047] Referring to the data set forth above in Table 5A, all the films containing COC, regardless of the content of COC, exhibited the best performance. However, the films containing COC did not always exhibit the lowest WVTR values. Table 5B summarizes odor evaluations of various samples after 24 hours aging. In the panel testing noted in Table 5A and the 24 hour odor test rating of Table 5B, a rating of 5 indicates detection of a strong odor, whereas a rating of 1 indicates no odor detected. [0048] In certain embodiments, it may be preferred to use a COC such as the developmental grade COC noted in Table 3, in an odor barrier layer. The unique and extremely low modulus of the COC of Table 3 is believed to promote noise reduction in the resulting barrier film.

[0049] The flexible supports in the preferred multilayer constructions utilize a low density polyolefin and preferably, a polyolefin elastomer. A wide array of commercially available polyolefin elastomers can be used for one or both of the flexible support layers. Representative preferred examples of such materials include KRATON™ D1164P and G2832 available from Kraton Polymers US, LLC of Houston, TX; DOW AFFINITY™ DG8200 and DOW VERSIFY™ 3200 and 3000 from Dow Chemical Corp. of Midland, Ml; DYNAFLEX™ G2755 from GLS Corp. of McHenry, IL; SEPTON™ 2063 from Kuraray of Tokyo, Japan; and VISTAMAXX™ VM1100 from ExxonMobil Chemical Co. of Houston, TX. Table 6 set forth below presents representative modulus, tear strength, and density values for films made using these materials.

Table 6 - Summary of Modulus, Tear Strength and Density

Modulus [MPa] Tear Strength [g] Density

Core Resin Name

MD TD MD TD [g/cm ³ ]

KRATON™ D1164P 40.3 9.6 95 776 0.96

KRATON™ G2832 5.0 1.7 179 207 1.01

DOW AFFINITY™ DG8200 8.8 8.1 150 188 0.93

DYNAFLEX™ G2755 9.8 3.2 175 186 0.89

DOW VERSIFY™ 3200 52.8 59.3 368 1026 0.93

DOW VERSIFY™ 3000 128.9 138.4 554 1205 0.87

Kuraray SEPTON™ 2063 8.0 8.1 83 56 1.00

Exxon VISTAMAXX™ VM1100 7.1 7.6 108 111 0.98 [0050] Generally, a particular combination of properties is desired for the film material forming the flexible support(s) in the preferred ostomy multilayer film summarized in Tables 4A-4D. A relatively low modulus should contribute to lower noise. Tear strength should be relatively high. Density may also be important. Typically, preferred films exhibit a modulus of less than about 9.5 MPa for MD and less than about 9 MPa for TD; a tear strength of at least about 100 g for MD and at least about 108 for TD; and a density of less than 1.0 g/cm ³ . Preferably, preferred films exhibit a modulus of less than or equal to about 9.3 MPa for MD and less than or equal to about 8.8 MPa for TD; a tear strength of at least or about 108 g for MD and at least or about 110 g for TD; and a density of less than or equal to 0.98 g/cm ³ . These combinations of properties for the materials forming the flexible supports, e.g. layers (ii) and (vi) in the preferred multilayer construction, have been found to provide a favorable combination of properties and promote ease of processing. However, the invention includes the use of suitable materials exhibiting only some of these properties. It will also be understood that the invention includes films exhibiting different properties. For example, it is contemplated that fully formed films would exhibit modulus values less than these values, and/or tear strength values that are greater than these values. The preferred materials of the group of commercially available materials listed in Table 6 are Exxon VISTAMAXX™ VM1100 and Dow AFFINITY™ DG8200.

[0051] It will be appreciated that the present invention multilayer barrier constructions are not limited to the use of these particular elastomers.

[0052] The inner antimicrobial layer preferably comprises an antimicrobial agent. In certain embodiments, the antimicrobial layer also preferably comprises one or more sealable polymers such as metallocene-catalyzed linear low density polyethylene (LLDPE) and ethylene vinyl acetate (EVA). One or more slip and/or antiblocking agents can also be incorporated into this layer. [0053] In certain embodiments, a multilayer barrier is provided that comprises G-EVOH in combination with one or more norbornene-based component(s). The norbornene component is preferably a cyclic olefin copolymer (COC), and most preferably an elastomeric COC. The G-EVOH and norbornene-based component can be included in the same layer together or provided in separate layers of the multilayer barrier. The G-EVOH and/or norbornene-based components can be utilized in combination with one or more additional components.

[0054] As stated previously, in addition to barrier properties, it is often desirable that a polymeric barrier film not emit noise when deflected, crumpled or otherwise moved. For example, in ostomy or incontinence applications, it is desirable that the ostomy or incontinence bag not emit noise. As will be appreciated, such articles are typically worn under a user's clothing so as to hide the article from view. Films or polymeric layers that are not quiet tend to emit undesirable noise when the user undergoes motion such as when walking or sitting. In the case of the preferred embodiment multilayer barrier films, the films are significantly quieter than comparable ostomy films.

Methods

[0055] The present invention also provides various methods. In one aspect, the invention provides a method for reducing noise associated with a polymeric barrier film. The method generally includes providing a polymeric barrier composition. Examples of such compositions include those previously described herein. The method also includes forming a film from the polymeric barrier composition. Extrusion techniques are preferred, however other known methods can be used for forming films. Prior to film forming, the method includes adding an effective amount of at least one noise suppressant to the polymeric barrier composition. The noise suppressant has (i) a viscosity of from about 25 cps to about 2800 cps at 25°C, (ii) a glass transition temperature of from about -95°C to about -72°C, (iii) a density of from about 0.81 g/cm ³ to about 0.85 g/cm ³ at 23°C, (iv) a flash point of from about 225°C to about 290°C, and (v) a molecular weight of from about 450 to about 3,000. As explained herein, in certain embodiments, it is preferred that the at least one polymer includes a cyclic olefin copolymer. In other embodiments, it is preferred that the at least one polymer includes ethylene vinyl alcohol (EVOH) and an ionomer. In many of the embodiments, it is preferred that the polymeric barrier composition is free of halogens. As previously described herein, it is generally preferred that the noise suppressant is a compound including carbon and hydrogen and generally free from functional groups selected from hydroxide, aryls and substituted aryls, halogens, alkoxys, carboxylates, esters, acrylates, oxygen, nitrogen, and carboxyl.

[0056] The various layers and films can be extruded, coated, or otherwise formed by techniques known in the art. Co-extrusion techniques can also be utilized. For certain applications in which increased toughness and/or durability are desired, films can be blown.

[0057] The preferred embodiment barrier film construction is believed to exhibit several advantages over currently known ostomy films. The preferred films are halogen-free and avoid the use of polyvinylidene chloride (PVDC). The preferred films are quieter and exhibit significantly less "rustle". And, the preferred films exhibit superior odor blocking characteristics. Furthermore, the preferred films exhibit a combination of some and preferably all of these features. The film construction may be transparent or contain coloring agents.

[0058] Many other benefits will no doubt become apparent from future application and development of this technology.

[0059] All patents, published applications, and articles noted herein are hereby incorporated by reference in their entirety.

[0060] It will be understood that any one or more feature or component of one embodiment described herein can be combined with one or more other features or components of another embodiment. Thus, the present invention includes any and all combinations of components or features of the embodiments described herein.

[0061] As described hereinabove, the present invention solves many problems associated with previously known compositions, films, multilayer assemblies, and related methods. However, it will be appreciated that various changes in the details, materials and arrangements of components and operations, which have been herein described and illustrated in order to explain the nature of the invention, may be made by those skilled in the art without departing from the principle and scope of the invention, as expressed in the appended claims.