Patent Publication Number: US-2013245592-A1

Title: Chlorobutyl rubber-based self-resealing septum and closure assembly

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the filing benefit of U.S. Provisional Patent Application Ser. No. 61/612,513, filed Mar. 16, 2012, the disclosure of which is hereby incorporated herein by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     This invention relates generally to septa, and more particularly to a penetrable and self-resealing septum and closure assembly, which can be used for storing non-aqueous liquids in the chemical, medical, and biochemical industries. 
     BACKGROUND OF THE INVENTION 
     Septa are piercable, mechanical barriers typically positioned between a vessel and its contents (usually a liquid) and the vessel&#39;s ambient environment. In such a configuration, a septum prevents contamination of the vessel contents and/or contamination of the environment by the vessel contents. The ability of the septum to maintain this separation is important for non-aqueous solvents and chemical reagents, especially hygroscopic or reactive reagents that require isolation from ambient laboratory conditions. For example, non-aqueous solvents such as dimethylsulfoxide and acetone can readily absorb atmospheric moisture upon exposure, and reactive reagents such as organolithium reagents can readily react with oxygen and atmospheric moisture. As such, for extended storage capability, it is important that a septum maintains its ability to prevent contamination after an initial piercing by a member such as a small gauge tube. 
     A typical septum is generally comprised of resilient material, pressed or otherwise inserted into a rigid collar, such as a vessel neck or cap so as to hold the elastomer under radial compression. Depending on the nature of the vessel contents, the septum may be optionally coated on one or both sides by an inert polymer such as a fluoropolymer, which are generally inelastic as compared to the resilient material. 
     When pierced by a small gauge tube, the resilient material creates a seal around the tube with a radial reaction force. When the tube is withdrawn, the resilient material forces the hole closed to form a substantially contiguous closed condition, thus, resealing the vessel. In the event that the septum is coated with an inert polymer material on the vessels content side of the septum, the tube generally leaves a hole that does not substantially close thereby permitting exposure of the resilient material to the vessel&#39;s contents. 
     Accordingly, in order to provide extended storage capability, the resilient material making up the septum needs to demonstrate compatibility with the vessel&#39;s contents. Because the chemical reactivity properties of non-aqueous solvents and chemical reagents are highly variable and dependent on their specific identity, often times many different types of resilient materials need to be tested and matched according to the resilient material&#39;s non-reactivity with the solvents or reagents. Often times the match is less than ideal, resulting in a premature breakdown of the contiguous closed hole, which permits contact between the vessel&#39;s contents and the ambient air. 
     Based on the foregoing, there is a need for a septum comprising a single species of resilient material that demonstrates broad compatibility with non-aqueous solvents and chemical reagents, and is simple to fabricate. 
     SUMMARY OF THE INVENTION 
     The present invention overcomes the foregoing and other shortcomings and drawbacks of re-sealing septa and closure assemblies heretofore known. While the invention will be described in connection with certain embodiments, it will be understood that the invention is not limited to these embodiments. On the contrary, the invention includes all alternatives, modifications and equivalents as may be included within the spirit and scope of the present invention. 
     In accordance with the principles of the present invention, a septum for use in a self-resealing closure assembly for a container is provided. The septum, which is suitable for closing an opening in a container, enables storing non-aqueous liquids, such as organic solvents, liquid organic compounds, water-reactive or oxygen-reactive compounds, or combinations thereof. The septum is particularly designed to provide re-sealing properties to containers after having been punctured by a hollow member, such as a needle, to preserve a separation of the non-aqueous liquid from the ambient environment outside of the container. 
     In one embodiment, a septum for use in a self-resealing closure assembly for a container is provided. The septum is a laminate structure penetrable by a member in an axial direction and a portion of the laminate structure is configured to elastically distend to pass the member through a tear in the septum and to be self-closing by returning opposite edges of the tear to a substantially contiguous closed condition after withdrawal of the member and which maintains a seal following member penetration in an axial direction and withdrawal. The septum includes a first layer of a resilient material derived from halobutyl rubber, such as chlorobutyl rubber, and having first and second opposed surfaces, and a second layer of a non-elastic polymer extending across, and bonded to, the first surface of the first layer. The first layer has a thickness within the range from about 2 mm to about 10 mm. The second layer has a thickness within the range from about 0.03 mm to about 1 mm. 
     In an embodiment, a self-resealing closure assembly for a container is provided, the assembly enables storing non-aqueous liquids, such as organic solvents, liquid organic compounds, water-reactive or oxygen-reactive compounds, or combinations thereof. The self-resealing closure assembly includes a septum, a retaining mechanism of inelastic material for supporting the septum, and a cap of inelastic material. The septum is particularly designed to provide re-sealing properties to containers after having been punctured by a hollow member, such as a needle, to preserve a separation of the non-aqueous liquid from the ambient environment outside of the container. 
     In one aspect of the self-resealing closure assembly, the septum is a laminate structure penetrable by a member in an axial direction and a portion of the laminate structure is configured to elastically distend to pass the member through a tear in the septum and to be self-closing by returning opposite edges of the tear to a substantially contiguous closed condition after withdrawal of the member and which maintains a seal following member penetration in an axial direction and withdrawal. The septum includes a first layer of a resilient material derived from a halobutyl rubber, such as chlorobutyl rubber, and having first and second opposed surfaces, and a second layer of a non-elastic polymer extending across, and bonded to, the first surface of the first layer. 
     In another aspect of the self-resealing closure assembly, the retaining mechanism of inelastic material has an inner and an outer surface, wherein the inner surface of the retaining mechanism is configured to make closing engagement with a rim of the container, and wherein the septum is supported in an opening defined in the retaining mechanism. In a further aspect, the cap of inelastic material configured to engage with the outer surface of the container or the retaining mechanism. 
     In another aspect of embodiments of the present invention, a method of preserving a non-aqueous liquid in a container is provided, the method includes storing the non-aqueous liquid within a self-resealing container assembly according to embodiments of the present invention. 
     The above and other objects and advantages of the present invention shall be made apparent from the accompanying drawings and the description thereof. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with a general description of the invention given above, and the detailed description given below, serve to explain the invention. 
         FIG. 1  illustrates in partial perspective view a self-resealing non-aqueous liquid container assembly in accordance with an embodiment of the present invention; 
         FIG. 2  illustrates in perspective view a disassembled self-resealing closure assembly of the self-resealing non-aqueous liquid container assembly shown in  FIG. 1 ; 
         FIG. 3  illustrates in perspective view a puncturable septum for the disassembled self-resealing closure assembly shown in  FIG. 2 ; 
         FIG. 3A  is a cross-sectional view taken along line  3 A- 3 A in  FIG. 3  depicting the puncturable septum in the self-resealing closure assembly of  FIG. 2 ; 
         FIG. 4  is a partial transverse cross-sectional view of the self-resealing non-aqueous liquid container assembly shown in  FIG. 1 ; and 
         FIG. 5  is a partial transverse cross-sectional view of a self-resealing non-aqueous liquid container assembly according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION 
     Referring now to the figures, and to  FIG. 1  in particular, an improved self-sealing non-aqueous liquid container assembly  10  is shown in accordance with an embodiment of the present invention. The container assembly  10  generally includes a self-sealing closure assembly  14  affixed to a container  18  that contains a non-aqueous liquid  20 , as shown in the illustrated embodiment. As shown in  FIG. 2 , the self-sealing closure assembly  14  generally includes a septum  22 , a retaining mechanism  24  for the septum that is configured to make a closing engagement with a rim of the container, as well as to support the septum  22 , and a cap  28  configured to engage with an outer surface of the retaining mechanism  24 . In an alternative embodiment (not shown), the cap  28  may be configured to engage with container  18 . 
     According to embodiments of the present invention, the septum  22  is a laminate structure including a first layer  30  of a resilient material having a first surface  34  and a second surface  36 , where the first and the second surfaces  34 ,  36  are opposing surfaces, and a second layer  40  of a non-elastic polymer extending across, and bonded to, the first surface  34  of the first layer  30 . According to an embodiment shown in  FIG. 3A , which is a cross-sectional view taken along line  3 A- 3 A of  FIG. 3 , the septum  22  further comprises a third layer  42  of a non-elastic polymer extending across, and bonded to, the second surface  36  of the first layer  30 , such that the first layer  30  of resilient material is sandwiched between two layers  40 ,  42  of non-elastic polymers. 
     According to embodiments of the present invention, the resilient material is derived from a halobutyl rubber, such as a chlorobutyl rubber. As used herein, the phrase “chlorobutyl rubber” refers to a chlorinated butyl elastomer. Chlorinated butyl elastomers suitable for use in the embodiments of the present invention include, but are not limited to, those elastomers obtained by chlorination of butyl rubber, which is a copolymer of an isoolefin, and a co-monomer such as a C 4  to C 6  conjugated diolefin co-monomer or an alkyl-substituted vinyl aromatic co-monomer. An exemplary isoolefin includes isobutene. An exemplary conjugated diolefin co-monomer includes isoprene, and an exemplary vinyl aromatic co-monomer includes C 1 -C 4 -alkyl substituted styrene. Examples of chlorinated butyl elastomers that are commercially-available include chlorinated isobutene-isoprene copolymer (CIIR), or chlorinated isobutene-methylstyrene copolymer (CIMS). 
     Chlorinated butyl elastomers typically contain in the range of from 0.1 to 10 weight percent, for example 0.5 to 5 weight percent, of repeating units derived from the diolefin, and in the range of from 90 to 99.9 weight percent, for example 95 to 99.5 weight percent, of repeating units derived from the isoolefin, based upon the hydrocarbon content of the polymer, and in the range of from 0.1 to 9 weight percent, for example from 0.75 to 2.3 weight percent, chlorine, based upon the chlorobutyl polymer. According to an embodiment, the chlorinated butyl elastomer comprises isobutene and isoprene. A typical chlorinated butyl elastomer has a molecular weight, expressed as the Mooney viscosity according to DIN 53 523 (ML 1+8 at 125° C.), in the range of from 25 to 60. 
     The resilient material can also include commonly used additives such as stabilizers and fillers. Suitable stabilizers include calcium stearate and epoxidized soy bean oil, which may be present in an amount in the range of from 0.5 to 5 parts by weight per 100 parts by weight of the chlorinated butyl rubber (phr). Suitable fillers include, for example, kaolin, titanium dioxide, carbon blacks, such as those carbon blacks that can be prepared by the lamp black, furnace black or gas black process and have BET specific surface areas of 20 to 200 m 2 /g, for example, SAF, ISAF, HAF, FEF or GPF carbon blacks. According to an exemplary embodiment, the chlorobutyl rubber-based resilient material may comprise white kaolin filler, titanium dioxide, and carbon N600, available from Gummi-Wöhleke GmbH—Siemensstraβe 25-D-31135 Hildesheim (CIIR). 
     According to an embodiment, the first layer  30  of resilient material has a thickness in the range from about 1 mm to about 10 mm. For example, the thickness of the first layer  30  may be about 1 mm, about 2 mm, about 3 mm, about 4 mm, about 5 mm, about 6 mm, about 7 mm, about 8 mm, about 9 mm, or about 10 mm. In one aspect, the thickness of the first layer  30  may be uniform. Alternatively, the thickness of the first layer  30  may be greater in a central portion, or greater in the periphery, of the septum  22 . According to an embodiment, the thickness of the first layer is about 3 mm and is substantially uniform. 
     According to embodiments of the present invention, the second layer  40  of a non-elastic polymer is positioned toward the non-aqueous liquid contents side of the septum  22 . Insofar as the second layer  40  can be directly contacted by the non-aqueous liquid  20  of the container  18 , the non-elastic polymer should be selected so as to be compatible with any of the non-aqueous liquids to which septum  22  may be exposed in its intended use. In other words, the non-elastic polymer should be a substantially chemically inert polymer. Accordingly, suitable non-elastic polymers for the second layer  40  include fluoropolymers, such as a polytetrafluoroethylene (PTFE), a (perfluoroalkoxy) fluoropolymer (PFA), and a fluorinated ethylene-propylene polymer (FEP). Exemplary fluoropolymers include, but are not limited to, TEFLON®, TEFLON® PFA, and TEFLON® FEP, which are commercially available from E. I. DuPont de Nemours and Company, Wilmington, Del. Other brand names for PFA granules are Neoflon® PFA from Daikin or Hyflon® PFA from Solvay Solexis. PFA is characterized as having properties similar to that of polytetrafluoroethylene (PTFE), but PFA differs from the PTFE resins in that it is generally melt-processable using conventional injection molding and screw extrusion techniques. PFA and FEP both share PTFE&#39;s useful properties of low coefficient of friction and non-reactivity, but are more easily formable. For example, PFA is softer than PTFE and melts at 305° C. According to one embodiment, the non-elastic polymer is a (perfluoroalkoxy) fluoropolymer (PFA). 
     According to another embodiment, the septum  22  further comprises a third layer  42  of a non-elastic polymer extending across, and bonded to, the second surface  36  of the first layer  30 , such that the first layer  30  of resilient material is sandwiched between two layers of non-elastic polymers. The third layer  42  of a non-elastic polymer is positioned away from the non-aqueous liquid contents side of the septum  22 , i.e., toward the ambient environment. Accordingly, non-elastic polymers suitable for the third layer  42  are not generally limited by their chemical reactivity with the non-aqueous liquid. However, according to an embodiment of the present invention, the third layer  42  may comprise fluoropolymers, such as a polytetrafluoroethylene, a (perfluoroalkoxy) fluoropolymer, and a fluorinated ethylene-propylene polymer, and thereby not unnecessarily confine the septum  22  to a single orientation. According to an embodiment, the second and third layer  40 ,  42  comprise the same fluoropolymer. 
     According to embodiments of the present invention, the second and/or third layer  40 ,  42  have a thickness less than about 1 mm. According to one embodiment, the thickness is within the range from about 0.03 mm to about 1 mm. For example, the thickness of the second layer  40  or the third layer  42  may be independently about 0.03 mm, about 0.05 mm, about 0.1 mm, about 0.15 mm, about 0.2 mm, about 0.25 mm, about 0.5 mm, or about 1 mm. 
     The laminate structure of the septum  22  can be fabricated in any of a number of ways. One such way includes bonding the three layers together with a flexible adhesive or other suitable means, such as stitching or heat pressing. Alternatively, where the non-elastic polymer can be provided as a liquid, the polymer may be applied to the first and/or second surface  34 ,  36  of the first layer  30  by spray coating or extruding the non-elastic polymer onto the first layer  30  of resilient material. The bonded non-elastic material assists the resilient material in providing self-resealing properties. 
     With reference to  FIG. 4  and in accordance with embodiments of the present invention, the septum  22  can be used in combination with a retaining mechanism  24  of inelastic material having an inner  46  and an outer  48  surface. The inner surface  46  of the retaining mechanism  24  is configured to make closing engagement with a rim  50  of the container  18 , and optionally, the outer surface  48  can be configured to make closing engagement with cap  28 . Accordingly, the retaining mechanism  24  may be generally tubular in shape with internal threading  53  provided on the inner surface  46  of the retaining mechanism  24  to provide frictional engage with complementary threading  54  on an outer surface  56  of container  18 . The retaining mechanism  24  can further include a protruding member  57 , which provides obstructive interference with a complementary protruding member  58  on the outer surface  60  of the container  18 , should removal of the retaining mechanism  24  be attempted. 
     The septum  22  is supported in an opening  62  defined in the retaining mechanism  24 . The retaining mechanism  24  is adapted to support the septum  22  and thereby facilitate direct and intimate contact between the second layer  40  of the septum  22  and the rim  50  of the container  18 , which provides the necessary barrier between the non-aqueous liquid and the surrounding atmosphere. Accordingly, the opening  62  is configured to provide a snug fit of the septum  22  in the opening  62 . According to the embodiment shown in  FIG. 4 , the inner surface  46  of the retaining mechanism  24  can further include a raised portion  63  that is axially disposed above the rim  50  and provides frictional retention of the septum  22  between the retaining mechanism  24  and the rim  50  upon tightening of the retaining mechanism  24  onto the container  18 . This frictional interference provided by the compressional deformation of the third layer  42  of the septum  22  by the raised portion  63  maintains the septum  22  within the opening  62  during application of downward axial force by a puncturing member, such as a needle. 
     Complementary support is provided to the septum  22  by the cross-member  64 , which is defined by apertures  70  in the retaining mechanism  24  that are axially disposed above the septum  22 . The cross-member  64  prevents deflection of the septum  22  when withdrawing the puncturing member from the septum  22 , or if the internal pressure of the container exceeds ambient pressure. 
     According to an embodiment of the present invention, a cap  28  of inelastic material is configured to engage with the outer surface  48  of the retaining mechanism  24 . In an alternative embodiment (not shown), the cap  28  can be configured to engage with a complementary configuration of the outer surface  48  of the container  18 . In continued reference to  FIG. 4 , the cap  28  is provided with internal threading  72 , which provides frictional engage with complementary threading  74  on the outer surface  48  of retaining mechanism  24 . The cap  28  may further include an outer cap liner  78  positioned at the upper inner surface  82  of the cap, which upon tightening of the cap  28  onto the retaining mechanism  24  provides a secondary level of closure to the container  18  beyond the septum  22 . The outer cap liner  78  may be a disc formed of a foamed fluoropolymer. Thus, according to the embodiment shown in  FIG. 4 , the septum  22 , the retaining mechanism  24 , and the cap  28  are generally concentrically circular. 
     In reference to  FIG. 5 , a needle  84  is shown entering the septum  22  through aperture  70  into a volume of the container  18  to gain access to the non-aqueous liquid  20  for retrieval of a sample of the liquid. 
     Self-resealing closure assemblies and self-resealing container assemblies in accordance with the principles of the present invention are suitable for the extended storage of non-aqueous liquids, especially after an initial puncture of the septum  22 . As used herein, “non-aqueous liquids” refers to liquids that are not water-based and do not contain water that has been intentionally added. However, adventitious presence of water is not excluded. For example, non-aqueous liquids may contain an amount of adventitious water equal to or less than about 100 parts per million (ppm). For particular solvents or other liquids, the suitable or preferred levels can be higher or lower. Non-aqueous liquids include, but are not limited to, organic solvents, liquid organic compounds, a water-reactive or oxygen-reactive compound, or combinations thereof. For example, non-aqueous liquids also include organic solvent solutions or mixtures comprising water-reactive or oxygen-reactive compounds. 
     Exemplary organic solvent classes include alcohols, amides, amines, aromatic amines, esters, ethers, hydrocarbons, halogenated hydrocarbons, ketones, nitriles, or sulfoxides. Exemplary organic solvents include, but are not limited to, acetone, acetonitrile, chloroform, diethyl ether, dimethylacetamide, dimethylformamide, dimethylsulfoxide, dioxane, ethanol, ethyl acetate, hexane, methanol, N-methylpyrrolidinone, pyridine, tetrahydrofuran, or toluene. 
     Exemplary liquid organic compounds include amines such as diethyl amine, benzyl amine, or ethanolamine; aldehydes such as acetaldehyde or crotonaldehyde; or phosphines such as tri-n-butylphosphine. 
     Exemplary water-reactive or oxygen reactive compounds include organometallic compounds, boranes, hydrides, Lewis acids, or acid halides. Organometallic compounds include, but are not limited to, organomagnesium compounds, organolithium compounds, organoaluminum compounds, or organozinc compounds. Exemplary organomagnesium compounds, which are also commonly known as Grignard reagents, include methylmagnesium bromide, phenylmagnesium bromide, methylmagnesium iodide, or phenylmagnesium chloride. Exemplary organolithium compounds include n-butyllithium, ethyllithium, phenyllithium, or tert-butyllithium. Exemplary organoaluminum compounds include diethylaluminum chloride, diisobutylaluminum chloride, or triethylaluminum. Exemplary organozinc compounds include diethyl zinc or dimethyl zinc. 
     Exemplary boranes include diethylmethoxyborane or tributylborane. Exemplary hydrides include diisobutylaluminum hydride or lithium aluminum hydride. Exemplary Lewis acids include boron tribromide or tin chloride. Exemplary acid halides include acetyl chloride. Other chemical reagents that may also be stored using the assemblies and methods disclosed herein also include bromine in acetic acid, or hydrogen chloride in ethanol. 
     Isotopic analogs of the foregoing non-aqueous liquids are also envisaged. For example, non-aqueous liquids also include deuterated nuclear magnetic resonance (NMR) solvents, such as acetone-d6, acetonitrile-d3, deuterium oxide, dichloromethane-d2, methanol-d4, dimethylsulfoxide-d6, or toluene-d8. 
     Thus, according to another embodiment of the present invention, a method of preserving a non-aqueous liquid in a container is provided. The method includes storing the non-aqueous liquid within the self-resealing container assemblies described above. For example, the herein described self-resealing container assemblies may inhibit the absorption of ambient moisture by hygroscopic non-aqueous liquids. 
     According to embodiments of the invention, a member, such as a hollow member in the form of a needle  84 , may penetrate septum  22  in axial direction to provide or remove contents to/from container  18 . The septum  22 , and more specifically the first layer  30  of resilient material of the septum  22 , maintains a seal around the puncturing member, and re-closes to maintain the seal in container  18  when the member is withdrawn from septum  22 . 
     Accordingly, the assemblies and methods disclosed herein provide acceptable compatibility with the non-aqueous liquids, as well as provide improved isolation of the non-aqueous liquid from the external ambient environment and thereby provide protection against adventitious water absorption or absorption. In one aspect, for an non-aqueous liquid having an initial water content, the self-resealing container assembly may provide less than about 100% increase in water content above the initial water content after storage of the container assembly at ambient conditions for extended durations after a single occurrence of puncturing the septum with an 18 gauge needle and retracting the 18 gauge needle. 
     In one embodiment, for an non-aqueous liquid having an initial water content equal to or less than about 100 ppm, the self-resealing container assembly may provide less than about 100% increase in water content above the initial water content after storage of the container assembly at ambient conditions for 6 weeks after a single occurrence of puncturing the septum with an 18 gauge needle and retracting the 18 gauge needle. In another embodiment, the self-resealing container assembly may provide less than about 100% increase in water content above the initial water content after storage of the container assembly at ambient conditions for 7 weeks, 8 weeks, or more. 
     In another aspect, the initial water content may be equal to or less than 75 ppm, or equal to or less than 50 ppm. 
     In another aspect, the increase in water content over the testing period may be less than about 75%, less than about 50%, or less than about 25% above the initial water content. 
     The present invention is illustrated by the following examples that are merely for the purpose of illustration and are not to be regarded as limiting the scope of the invention or the manner in which it can be practiced. 
     EXAMPLES 
     Comparative testing: Various septa, e.g., black Viton, red Viton, FKM, silicon, red SO203583T, may be tested for comparison to a septum comprising a resilient material derived from a halobutyl rubber, such as chlorobutyl rubber. Each septum is coated on a single side or on two sides with a fluoropolymer. The septum is placed in a retainer mechanism, which is subsequently affixed to a bottle containing a non-aqueous liquid, such as an organic solvent, a liquid organic compound, a water-reactive or oxygen-reactive compound, or a combination thereof. The fluoropolymer coated side is positioned toward the non-aqueous liquid. The septum is pierced with an 18 gauge needle and bottle assembly is inverted several times to simulate normal laboratory usage. The physical integrity of the pierced septa is visually evaluated. 
     For example, testing of various septa coated on a single side with a layer of a fluoropolymer against exemplary organic solvents may be performed, where each septum is placed in a retainer mechanism, which is subsequently affixed to a bottle containing a dry organic solvent (e.g., acetonitrile (ACN), dichloromethane (DCM), diethyl ether (DEE), tetrahydrofuran (THF), and toluene (TOL)). Two bottles for each septa and solvent are prepared, with one bottle being subjected to the following experimental testing regime: After the initial filling and sealing of the solvent container, each septum is pierced three times with an 18 gauge needle affixed to a syringe. For this testing protocol, the first puncture rinses the syringe, and either the second or the third puncture sample may be tested for water content. This puncturing protocol may be performed at weekly intervals with the physical integrity of the septum and the inversion test being performed each week. The water content may also be tested at weekly intervals, with the unpierced bottle being tested at the conclusion of the testing period. 
     According to one exemplary testing protocol, a chlorobutyl and an ethylene propylene diene monomer (EPDM) septa may be tested for comparison. Exemplary septum include, but are not limited to, EPDM bright one side 0.1 mm PTFE coating; Chlorobutyl grey with 0.25 mm PFA foil coating; Chlorobutyl black with 0.25 mm PFA foil coating; and EPDM bright 0.05 mm PFA coating with dark primer. 
     According to another exemplary testing protocol, the testing of single sided chlorobutyl rubber-based septa, (e.g., a single faced black chlorobutyl (supplier GW Silicones of Royalton, Vt.); and a single faced chlorobutyl grey coated with Fluorotec® Dalkyo fluoro resin D, B2-40, Westar® RS (supplier Adelphi Healthcare Packaging of West Sussex, UK) may be tested, where two ×30 ml bottles of each solvent filled using the two septa types, with one bottle of each solvent/septa combination being pierced once on day 0. The other samples remain unpierced until the completion of the testing period (week 7). Pierced septa may be visually examined each week and re-tested for water content on week 7. Unpierced septa may be pierced and solvent tested on final week (7) for comparison. Organic solvents analyzed may include acetone, diethylether (DEE), methanol (MeOH), dichloromethane (DCM), dimethylformamide (DMF), and tetrahydrofuran (THF), for example. 
     According to another exemplary testing protocol, the puncturing protocol describe above may be performed using an 18 gauge needle on a dual coated chlorobutyl rubber-based septa (double side coated CB, 0.25 PFA; Gummi-Wöhleke GmbH—Siemensstraβe 25-D-31135 Hildesheim) in combination with exemplary organic solvents, such as acetone, diethylether (DEE), methanol (MeOH), dichloromethane (DCM), dimethylformamide (DMF), and tetrahydrofuran (THF) to demonstrate the ability of the dual coated chlorobutyl rubber-based septa to inhibit the absorption of water. 
     While the present invention has been illustrated by the description of embodiments thereof, and while the embodiments have been described in considerable detail, it is not intended to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is, therefore, not limited to the specific details, representative apparatus and method, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the general inventive concept.