MX2008008826A - Room temperature curable organopolysiloxane composition - Google Patents

Abstract

This invention relates to a room temperature curable composition containing,inter alia, diorganopolysiloxane(s) and organic nanoclay(s), the cured composition exhibiting low permeability to gas(es).

Description

COMPOSITION OF ORGANOPOLISILOXANE CURABLE AT AMBIENT TEMPERATURE FIELD OF THE INVENTION This invention relates to a composition curable at room temperature that exhibits, upon curing, low permeability to the gas (s). BACKGROUND OF THE INVENTION Room temperature curable compositions (RTC) are well known for use as sealants or sealants. In the manufacture of Glass Insulating Units (IGU), for example, the glass panels are placed parallel to each other and sealed at their periphery such that the space between the panels, or the interior space, is completely enclosed. The interior space is typically filled with a gas or mixture of gases of low thermal conductivity, for example, argon. Current temperature curable silicone sealant compositions, while effective to some degree, still have only limited ability to prevent the loss of insulating gas from the interior space of an IGU. Over time, the gas will escape by reducing the thermal insulation effectiveness of the IGU to the point of disappearing. Therefore, there is a need for a RTC composition of reduced gas permeability. compared to that of the known RTC compositions. When used as the sealant for an IGU, a RTC composition of reduced gas permeability will retain the insulating gas intra-panels for a longer period of time compared to that of a more permeable PTC composition and will therefore extend the insulation properties of the IGU over a longer period of time. BRIEF DESCRIPTION OF THE INVENTION The present invention is based on the discovery that curable silanol-terminated diorganopolysiloxane combined with filler of a certain type when curing exhibits reduced gas permeability. The composition is especially suitable for use as a sealant where the high gas barrier properties in conjunction with the desired softness, processability and elasticity characteristics are important performance criteria. In accordance with the present invention, a curable composition is provided which comprises: a) at least one diorganopolysiloxane terminated in silanol; b) at least one crosslinker for the finished diorganopolysiloxane (s) in silanol; c) at least one catalyst for the crosslinking reaction; d) at least one organic nanoclay, and, optionally, e) at least one solid polymer having a gas permeability that is less than the permeability of the crosslinked diorganopolysiloxane (s). When used as a gas barrier, for example, in the manufacture of an IGU, the above composition reduces the gas loss (s) thus providing a longer service life of the article in which it is employed. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a graphical presentation of permeability data for the sealant compositions of Comparative Examples 1-2 and Examples 1-3 and 5-8. Figure 2 is a graphical display of permeability data for the sealant compositions of Comparative Examples 1-2 and Examples 4 and 9. DETAILED DESCRIPTION OF THE INVENTION The curable sealant composition of the present invention is obtained by mixing (a) at least one diorganopolysiloxane; (b) at least one crosslinker for the diorganopolysiloxane (s); (c) at least one catalyst for the crosslinking reaction; (d) at least one organic nanoclay; and, optionally, (e) at least one solid polymer having a gas permeability that is lower than the permeability of the crosslinked diorganopolysiloxane (s), the composition following the cure exhibits low permeability to the gas (s). ).

The compositions of the invention are useful for the manufacture of sealants, coatings, adhesives, gaskets, and the like, and are particularly suitable for use in intended sealants for glass insulating units. The viscosity of the dilanganopolysiloxane terminated in silanol which is employed in the curable composition of the invention can vary widely and advantageously varies within the range of from about 1,000 to about 200,000 cps at 25 ° C. Suitable silanol-terminated diorganopolysiloxanes (a) include those of the general formula: MaDbD'c where "a" is 2, and "b" is equal to or greater than 1 and "c" is zero or positive; Month where "x" is 0, 1 or 2 and "y" is either 0 or 1, subject to the limitation that x + y is less than or equal to 2, R1 and R2 each independently is a monovalent hydrocarbon group of up to 60 carbon atoms; D is R3R4SiO? 2; wherein R3 and R4 each independently is a monovalent hydrocarbon group of up to 60 carbon atoms; and D 'is R5RdSi02 / 2 wherein R5 and R6 each independently is a monovalent hydrocarbon group of up to 60 carbon atoms. Suitable crosslinkers (b) for the silanol-terminated diorganopolysiloxane (s) present in the composition of the invention include alkylsilicates of the general formula: (R140) (Rl50) (R160) (R170) Yes wherein R14, R15, R16 and R17 each independently is a monovalent hydrocarbon group of up to 60 carbon atoms. Crosslinkers of this type include, n-propyl silicate, tetraethylo silicate and methyltrimethoxysilane and similar alkyl-substituted alkoxysilane compounds, and the like. The catalysts (c) suitable for the crosslinking reaction of the finished diorganopolysiloxane (s) in silanol can be any of those known to be useful for facilitating the crosslinking of such siloxanes. The catalyst can be a non-metallic compound or a metal-containing compound. Examples of useful metal-containing compounds include those of tin, titanium, zirconium, lead, cobalt iron, antimony, manganese, bismuth and zinc. In one embodiment of the present invention, tin-containing compounds useful as crosslinking catalysts include dibutyltin dilaurate, dibutyltin diacetate, dibutyltin dimethoxide, tin octoate, isobutyltin triceroate, dibutyltin oxide, soluble dibutyltin oxide, bis dibutyltin diisooctylphthalate, bis-tripropoxysilyl dioctyltin, dibutyltin bis-acetylacetone, silylated dibutyltin dioxide, carbomethoxyphenyl tin tris-uberate, isobutyltin tricernate, dimethyltin dibutyrate, dimethyltin di-neodecanoate, triethyltin tartrate, dibutyltin dibenzoate, tin oleate, tin naphthenate, butyl tin-2-ethylhexylhexoate, tin butyrate, diorganotin bis-diketonates, and the like. Useful titanium-containing catalysts include: chelated titanium compounds, for example, 1,3-propanedioxytitanium bis (ethylacetoacetate); bis (ethylacetoacetate) of diisopropoxytitanium, and tetraalkyl titanates, for example, tetra n-butyl titanate and tetraisopropyl titanate. In yet another embodiment of the present invention, the diorganotin bis-diketonates are used to facilitate crosslinking in the silicone sealant or sealant composition.

The curable composition of the present invention includes at least one organic nanoclay filler (d). The nanoclays have a unique morphology with a dimension being in the range of nanometers. The nanoclays can form chemical complexes with an intercalator that bonds ionically to the surfaces in the middle of the layers that form the clay particles. This association of intercalant and clay particles results in a material that is compatible with many different types of host resins that allow the clay filler to disperse therein. The term "exfoliation" as used herein describes a process wherein the nanoclay lamella packs are separated from each other in a polymer matrix. During the exfoliation, the lamellae in the outermost region of each package are broken, exposing more lamellae for separation. The term "gallery" as used herein describes the space between the parallel layers of clay lamellae. The spacing of the gallery changes depending on the nature of the molecule or the polymer that occupies the space. An inter-layered space between the individual nanoclay lamellae varies, again depending on the type of molecules that occupy the space. The term "interleaver" as used herein includes any inorganic or organic compound that is able to enter the clay gallery and bond to its surface. The term "interleaved" as used herein designates a clay-chemical complex where the spacing of the clay gallery has incrd due to the process of surface modification. Under the appropriate conditions of temperature and shear, an interlayer is capable of exfoliation in a resin matrix. The expression "low gas permeability (s)" as applied to the cured composition of this invention will be understood to mean a coefficient of permeability to argon of not greater than about 900 barriers (1 barrier = 10").

(STP) / cm sec (cmHg)) mred according to the variable volume method - constant pressure at a pressure of 7.03 kg / cm2 (100 psi) and temperature of 25 ° C. The term "modified clay" as used herein means a clay material that has been treated with any inorganic or organic compound that is capable of undergoing ion exchange reactions with the cations present on the interlayer surfaces of the clay. The term "nanoclay" as used herein describes clay materials that possess a unique morphology with a dimension being in the nanometer range. Nanoclays can form chemical complexes with an interlayer that It bonds ionically to the surfaces in the middle of the layers that form the clay particles. This association of intercalant and clay particles results in a material that is compatible with many different types of host resins that allow the clay filler to disperse therein. The term "organic nanoclay" as used herein describes a nanoclay that has been treated or modified with an organic intercalator. The term "organoarcilla" as used herein means a clay or other layered material that has been treated with organic molecules (variously referred to as "exfoliation agents", "surface modifiers" or "intercalators") that are capable of ion exchange reactions with the cations present in the inter-layer surfaces of the clay. The nanoclays can be natural or synthetic materials. This distinction may influence the particle size and for this invention, the particles should have a side dimension of between about 0.01 μm and about 5 μm, and preferably between about 0.05 μm and about 2 μm, and more preferably between about 0.1 μm and about 1 μm. The thickness or vertical dimension of the particles can generally vary between about 0.5 nm and about 10 nm and preferably between about 1 nm and about 5 nm. Useful nanoclays for providing the organic nanoclay filler component of the composition of the invention include natural or synthetic phyllosilicates, particularly smectite clays such as montmorillonite, sodium montmorillonite, calcium montmorillonite, magnesium montmorillonite, nontronite, beidelite, volkonskoite, laponite. , hectorite, saponite, sauconite, magadite, kenyaite, sobockite, svindordite, stevensite, talc, mica, kaolinite, vermiculite, halloysite, aluminate oxides, or hydrotalcites, and the like, and mixtures thereof. In another embodiment, useful nanoclays include micaceous minerals such as illite and mixed stratified illite / smectite minerals such as rectorite, tarosovite, ledikite and mixtures of ilutas with one or more of the clay minerals named above. Any foamed, swellable material that sufficiently absorbs organic molecules to incr the inter-layer spacing between the phyllosilicate lamellae adjacent to at l about 5 angstroms, or at l about 10 angstroms, (when the phyllosilicate is mred dry) may used to produce the filler component to provide the curable composition of the invention. In an embodiment of the present invention, organic compounds that are useful for treating nanoclays and layered materials to provide the filler component herein include cationic surfactants such as ammonium, ammonium chloride, alkylammonium (primary, secondary, tertiary and quaternary), phosphonium or sulfonium sulfide derivatives, phosphines or aliphatic, aromatic or arylaliphatic amines. Other organic treatment agents for the nanoclays that may be used herein include amine compounds and / or quaternary ammonium compounds R6 R7 R8 N + X'each independently is an alkoxysilane group, alkyl group or alkenyl group of up to 60 carbon atoms and X is an anion such as Cl ", F", S04 ~, etc. Optionally, the curable composition herein may also contain at least one solid polymer (e) having a gas permeability that is less than the permeability of the crosslinked diorganopolysiloxane. Suitable polymers include polyethylenes such as low density polyethylene (LDPE), very low density polyethylene (VLDPE), linear low density polyethylene (LLDPE) and high density polyethylene (HDPE); polypropylene (PP), polyisobutylene (PIB), acetate polyvinyl (PVAc), polyvinyl alcohol (PVoH), polystyrene, polycarbonate, polyester, such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naptalate (PEN), glycol-modified polyethylene terephthalate (PETG), polyvinyl chloride (PVC), polyvinylidene chloride, polyvinylidene fluoride, thermoplastic polyurethane (TPU), acrylonitrile -butadiene-styrene (ABS), polymethylmethacrylate (PMMA), polyvinyl fluoride (PVF), polyamides (nylons), polymethylpentene, polyimide (Pl), polyetherimide (PEI), polyether ketone ether (PEEK), polysulfone, polyether sulfone, ethylene chlorotrifluoroethylene, polytetrafluoroethylene (PTFE), cellulose acetate, cellulose acetate butyrate, plasticized polyvinyl chloride, ionomers (Surtyn), polyphenylene sulfide (PPS), maleic-styrene anhydride, modified polyphenylene oxide (PPO), and the like and mix them. The optional polymer (s) may also be elastomeric in nature, examples include, but are not limited to ethylene-propylene rubber (EPDM), polybutadiene, polychloroprene, polyisoprene, polyurethane (TPU), styrene-butadiene styrene (SBS), styrene-ethylene-butadiene-styrene (SEEBS), polymethylphenyl siloxane (PMPS), and the like. These optional polymers can be mixed either alone or in combinations or in the form of copolymers, for example polycarbonate-ABS blends, polycarbonate polyester blends, grafted polymers such as, silane grafted polyethylenes, and silane-grafted polyurethanes. In one embodiment of the present invention, the curable composition contains a polymer selected from the group consisting of low density polyethylene (LDPE), very low density polyethylene (VLDPE), linear low density polyethylene (LLDPE), high density polyethylene. (HDPE), and mixtures thereof. In another embodiment of the invention, the curable composition has a polymer selected from the group consisting of low density polyethylene (LDPE), very low density polyethylene (VLDPE), linear low density polyethylene (LLDPE), and mixture thereof. . In yet another embodiment of the present invention, the optional polymer is a linear low density polyethylene (LLDPE). The curable composition may contain one or more other fillers in addition to component (d) of organic nanoclay. Additional fillers suitable for use herein include colloidal calcium carbonates and precipitates that have been treated with compounds such as stearic acid or stearate ester; reinforcing silicas such as fumed silicas, precipitated silicas, silica gels and hydrophobic silicas and silica gels; crushed and ground quartz, alumina, aluminum hydroxide, titanium hydroxide, diatomaceous earth, iron oxide, carbon black, graphite, mica, talc, and the like, and mixtures thereof. The curable composition of the present invention may also include one or more alkoxysilanes as adhesion promoters. Useful adhesion promoters include N-2-aminoethyl-3-aminopropyltriethoxysilane, α-aminopropyltriethoxy-silane, α-aminopropyltrimethoxysilane, aminopropyltrimethoxy-silane, bis-β-trimethoxysilylpropyl) amine, N-phenyl-β-aminopropyltrimethoxysilane, triaminofunctionaltrimethoxysilane,? -aminopropylmethyl-diethoxysilane,? -aminopropylmethyl-diethoxysilane, methacryloxypropyltrimethoxysilane, methylaminopropyltrimethoxy-silane,? -glycidoxypropylethyl-dimethoxysilane,? -glycidoxypropyltrimethoxysilane,? -glycide-xylethyltrimethoxysilane, beta- (3,4-epoxycyclohexyl) -propyltrimethoxysilane, β- ( 3, 4-epoxycyclohexyl) ethylmethyldimethoxy-silane, isocyanatopropyltriethoxysilane, isocyanatopropylmethyldimethoxysilane, β-cyanoethyltrimethoxysilane, α-aryloxypropyltrimethoxysilane, α-methacryloxypropylmethyldimethoxysilane, 4-amino-3, 3-di-ethylbutyltrimethoxysilane, and N-ethyl-3-trimethoxysilyl -2-methylpropanamine and the like. In one embodiment, the adhesion promoter can be a combination of n-2-aminoethyl-3-aminopropyltrimethoxysilane and 1,3,5-tris (trimethoxysilylpropyl) isocyanurate. The compositions of the present invention can also include one or more non-ionic surfactants such as polyethylene glycol, polypropylene glycol, ethoxylated castor oil, oleic acid ethoxylate, alkylphenol ethoxylates, copolymers of ethylene oxide (EO) and propylene oxide (PO) and copolymers of silicones and polyethers (copolymers) silicone polyether), copolymers of silicones and copolymers of ethylene oxide and propylene oxide and mixtures thereof. The curable compositions of the present invention can still include other ingredients that are conventionally employed in compositions containing RTC silicone such as colorants, pigments, plasticizers, antioxidants, UV stabilizers, biocides, etc., in known and conventional amounts provided that do not interfere with the properties desired for the cured compositions. The amounts of finished diorganopolysiloxane (s) in silanol, crosslinker (s), crosslinking catalyst (s), organic nanoclay (s), optional solid (s) polymer (s) of lower permeability to the gas that the crosslinked diorganopolysiloxane (s), optional filler (s) are (s) different from the organic nanoclay, optional adhesion promoter (s) and ionic surfactant (s) ( s) optional (s) may vary widely and, advantageously, they can be selected from the ranges indicated in the following table.

TABLE 1: Quantity Ranges (Percent in Weight) of the Components of the Curable Composition of the Invention The curable compositions herein can be obtained by methods that are well known in the art, for example, melt mixing, extrusion mixing, solution mixing, dry mixing, mixing in a Banbury mixer, etc., in the presence of moisture for provide a substantially homogeneous mixture. Preferably, the methods for mixing the polymers of diorganopolysiloxane with polymers can be carried out by contacting the components in a drum or other physical medium. of mixing, followed by melt mixing in an extruder. Alternatively, the components can be melt-blended directly in an extruder, Brabender or any other melt mixing means. The invention is illustrated by the following non-limiting examples. COMPARATIVE EXAMPLE 1 AND EXAMPLES 1-4 A mixture of silanol-terminated polydimethylsiloxanes (PDMS), specifically, Silanol 5000, a silanol-terminated polydimethylsiloxane of 5000 is nominal and Silanol 50,000, a silanol-terminated polydimethylsiloxane of 50,000 is nominal, both available at from Gelest, Inc., were mixed in a 100 ml beaker with Cloisite 15A ("C-15A", a modified montmorillonite clay with 125 milliequivalents of dimethyl ammonium chloride dehydrogenated bait per 100 g of available clay from from Southern Clay Products) or SF ME100 (a synthetic fluorohectorite having the general formula NaMg2.5Si4O? 0 (Fa0Hi-C () 2 (0.8 <= a < = l.0) available from Unicorp, Japan) using a hand mixer for 10-15 minutes and then placed in a vacuum desiccator for 5 minutes to remove the air bubbles generated during mixing.The mixtures were made with the amounts of nanoclay varying in the range from 1 to 10 percent by weight.

Following the above procedure, the curable compositions of the following Examples were obtained: Comparative Example 1: Mixture of 50 grams (Silanol 5000 and Silanol 50000 @ 50:50) Example 1: Mixture of 48.75 grams (Silanol 5000 and Silanol 50000 @ 50: 50) + 1.25 grams of Cloisite C-15A clay Example 2: Mixture of 47.5 grams (Silanol 5000 and Silanol 50000 @ 50:50) + 2.5 grams of Cloisite C-15A clay Example 3: Mixture of 45 grams (Silanol 5000 and Silanol 50000 @ 50:50) + 5 grams of Cloisite clay C-15A Example 4: Mix of 45 grams (Silanol 5000 and Silanol 50000 @ 50:50) + 5 grams of clay SF ME100 The above-mentioned mixtures were then used to make sheets cured as follows: the PDMS-nanoclay formulations were mixed with n-propyl silicate ("NPS", a crosslinker) and solubilized dibutyl tin oxide ("DBTO", a crosslinking catalyst), as listed in Table 2, using a hand mixer for 5-7 minutes with the air bubbles being removed by vacuum. Each mixture was poured into a mold to form Teflon sheets and kept for 24 hours under ambient conditions (25 ° C and 50% humidity) to partially cure the PDMS components. The partially cured sheets were removed from the mold after 24 hours and kept at room temperature for seven days to complete the cure.

TABLE 2 Curable Compositions The permeability to argon of the above curable compositions was measured using a gas permeability mechanism. The measurements were based on the variable volume method at 100 psi pressure and at a temperature of 25 ° C. The permeability measurements were repeated under identical conditions 2-3 times to ensure reproducibility. The permeability data are graphically presented in Figures 1 and 2. COMPARATIVE EXAMPLE 2 AND EXAMPLES 5-9 To provide a C-15A clay to 1 percent by weight (see Example 5, Table 3): 227.7 g of OMCTS (octamethylcyclotetrasiloxane) and 2.3 g of C-15A were introduced into a three-necked round bottom flask equipped with a stirrer in the cap and condenser. The mixture was stirred at 250 rpm for 6 hours at room temperature. The temperature was increased to 175 ° C while stirring was continued. 0.3 g of CsOH in 1 ml of water was added to the reaction vessel through a septum. After 15 minutes, the OMCTS polymerization was started and 0.5 ml of water was then added with 0.5 ml of additional water being added after 5 minutes. Heating and stirring was continued for 1 hour after which 0.1 ml of phosphoric acid was added for neutralization. The pH of the reaction mixture was determined after 30 minutes. Stirring and heating was continued for another 30 minutes and the pH of the reaction mixture was determined again to ensure complete neutralization. The distillation of the cyclic compounds was carried out at 175 ° C and subsequently the mixture was cooled to room temperature. The same procedure was followed with 2.5, 5 and 10% by weight of C-15A (see Examples 6-8, Table 3). Similar in-situ polymerization procedures were followed with 10% high aspect ratio clay (SF ME100) (see Example 9, Table 3). The in-situ polymer with different amounts of clay was then used to make cured sheets as follows: PDMS-nanoclay formulations The in-situ mixed with crosslinker and catalyst NPS DBTO solubilized using a hand mixer for 5-7 min with air bubbles being removed by vacuum. The mixture was then poured into a mold to form Teflon sheets and kept for 24 hours under ambient conditions (25 ° C and 50% humidity). The partially cured sheets were removed from the mold after 24 hours and kept at room temperature for seven days to complete the cure.

TABLE 3 Curable Compositions The permeability to argon was measured using a gas permeability mechanism as in the examples previous The measurements were based on the variable volume method at 7.03 kg / cm2 (100 psi) of pressure and at a temperature of 25 ° C. The measurements were repeated under identical conditions 2-3 times to ensure reproducibility. The permeability data are presented graphically in Figures 1 and 2. As shown in the data, the permeability to argon in the case of the cured sealing compositions of the invention (Examples 1-3 and 5-8 of Figure 1 and Examples 4 and 9 of Figure 2) were significantly less than that of the cured sealing compositions outside the scope of the invention (Comparative Examples 1 and 2 of Figures 1 and 2). In all, while the argon permeability coefficients of the sealant compositions of Comparative Examples 1 and 2 exceed the 900 barriers, those of Examples 1-9 Illustrative of the sealing compositions of this invention did not exceed 900 barriers and in some cases , were well below this level of argon permeability coefficient (see, in particular, examples 3, 8 and 9). While the preferred embodiments of the present invention have been illustrated and described in detail, various modifications of, for example, the components, the Materials and parameters will become apparent to those skilled in the art, and it is intended to cover all such modifications and changes within the scope of this invention in the appended claims.

Claims (23)

1. CLAIMS: 1. A curable composition, characterized in that it comprises: a) at least one diorganopolysiloxane terminated in silanol; b) at least one crosslinker for the finished diorganopolysiloxane (s) in silanol; c) at least one catalyst for the crosslinking reaction, - d) at least one organic nanoclay; and, optionally, e) at least one solid polymer having a gas permeability that is less than the permeability of the crosslinked diorganopolysiloxane (s).
2. 2. The composition of claim 1, characterized in that the diorganopolysiloxane terminated in silanol (a) has the general formula: MaDbD'c where "a" is 2, and "b" is equal to or greater than 1 and "c" is zero or positive; Month (HO) 3.x.yR ^ R2ySi01 / 2 where "x" is 0, 1 or 2 and "y" is either 0 or 1, subject to the limitation that x + y is less than, or equal to 2, R1 and R2 each independently is a hydrocarbon group monovalent of up to 60 carbon atoms; D is R3R4SiO? / 2¡ wherein R3 and R4 each independently is a monovalent hydrocarbon group of up to 60 carbon atoms; and D 'is • R5R6Si02 / 2 wherein R5 and R6 each independently is a monovalent hydrocarbon group of up to 60 carbon atoms.
3. 3. The composition of claim 1, characterized in that the crosslinker (b) is an alkylsilicate having the formula: (R, 40) (150) (Rl60) (R170) Si where R14, R15, R16 and R17 are independently selected from the monovalent Ci to C6 hydrocarbon radicals.
4. 4. The composition of claim 1, characterized in that the catalyst (c) is a tin catalyst. The composition of claim 4, characterized in that the tin catalyst is selected from the group consisting of dibutyltin dilaurate, dibutyltin diacetate, dibutyltin dimethoxide, tin octoate, isobutyltin tricermate, dibutyltin oxide, bis-diisooctylphthalate of dibutyltin, bis-tripropoxysilyl dioctyltin, dibutyltin bis-acetylacetone, silylated dibutyltin dioxide, carbomethoxyphenyl tris-uberate tin, isobutyltin triceroate, dimethyltin dibutyrate, dimethyltin di-neodecanoate, triethyltin tartarate, dibutyltin dibenzoate, tin oleate, tin naphthenate, butyl tin-2-ethylhexylhexoate, tin butyrate, diorganotin bis-diketonates, and mixtures thereof 6. The composition of claim 1, characterized in that the nanoclay portion of the organic nanoclay (d) is selected from the group consisting of montmorillonite, sodium montmorillonite, calcium montmorillonite, magnesium montmorillonite, nontronite, beidelite, volkonskoite, laponite, hectorite, saponite, sauconite, magadite, kenyaite, sobockite, svindordite, estevensite, vermiculite, halloysite, aluminate oxides, hydrotalcite, illite, rectorite, tarosovite, ledikite, kaolinite, and mixtures thereof. The composition of claim 1, characterized in that the organic portion of the organic nanoclay (d) is at least one tertiary amine compound R3R4R5N and / or a compound R6RR8N + X "of quaternary ammonium wherein R3, R4, R5, R6, R7 and R8 each independently is an alkyl, alkenyl or alkoxy silane group of up to 60 carbon atoms and X is an anion 8. The composition of claim 6, characterized wherein the nanoclay portion of the organic nanoclay (d) is modified with ammonium, primary alkylammonium, secondary alkylammonium, tertiary alkylammonium, quaternary alkylammonium, phosphonium derivatives of aliphatic, aromatic or arylaliphatic sulphides, phosphines or amines or sulphonium sulfonium derivatives , aliphatic, aromatic or arylaliphatic phosphines or amines. The composition of claim 1, characterized in that the solid polymer (e) is selected from the group consisting of low density polyethylene, very low density polyethylene, linear low density polyethylene, high density polyethylene., polypropylene, polyisobutylene, polyvinyl acetate, polyvinyl alcohol, polystyrene, polycarbonate, polyester, such as, polyethylene terephthalate, polybutylene terephthalate, polyethylene naptalate, glycol-modified polyethylene terephthalate, polyvinyl chloride, polyvinylidene chloride, fluoride polyvinylidene, thermoplastic polyurethane, acrylonitrile-butadiene-styrene, polymethylmethacrylate, polyvinyl fluoride, polyamides, polymethylpentene, polyimide, polyetherimide, polyether ether ketone, polysulfone, polyether sulfone, ethylene chlorotrifluoroethylene, polytetrafluoroethylene, cellulose acetate, cellulose acetate butyrate, plasticized polyvinyl chloride, ionomers, polyphenylene sulfide, maleic-styrene anhydride, modified polyphenylene oxide, ethylene-propylene rubber, polybutadiene, polychloroprene, polyisoprene, polyurethane, styrene-butadiene-styrene, styrene-ethylene-butadiene-styrene, polymethylphenyl siloxane and mixtures thereof. The composition of claim 1, characterized in that it further comprises at least one optional component selected from the group consisting of adhesion promoter, surfactant, dye, pigment, plasticizer, filler different from organic nanoclay, antioxidant, UV stabilizer, and biocide The composition of claim 10, characterized in that the adhesion promoter is selected from the group consisting of n-2-aminoethyl-3-aminopropyltrimethoxysilane, 1,3,5-tris (trimethoxysilylpropyl) isocyanurate,? -aminopropyltriethoxy-silane ?, aminopropyltrimethoxysilane, aminopropyltrimethoxysilane, bis -? - trimetoxisilipropil) amine, N-phenyl -? - aminopropyltrimethoxysilane, triaminofuncionaltrimetoxisilano, -aminopropilmetildietoxisilano, -aminopropilmetildietoxi silane methacryloxypropyltri ethoxysilane, methoxysilane metilaminopropiltri-, -glicidoxipropiletildimetoxisilano,???? - glycido-xipropiltrimethoxysilane, β-glycidoxyethyltrimethoxysilane, β- (3, 4-epoxycyclohexyl) propyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethylmethyldimethoxysilane, isocyanatopropyltriethoxysilane, isocyanatopropylmethyldimethoxy silane, β-cyanoethyltrimethoxysilane, α-aryloxypropyltrimethoxysilane, β-methacryloxypropylmethyldimethoxysilane, 4-amino-3,3-dimethylbutyltrimethoxysilane, n-ethyl-3-trimethoxy-silyl-2-methylpropanamine, and mixtures thereof . The composition of claim 10, characterized in that the surfactant is a nonionic surfactant selected from the group consisting of polyethylene glycol, polypropylene glycol, ethoxylated castor oil, oleic acid ethoxylate, alkylphenol ethoxylates, copolymers of ethylene oxide and oxide of propylene and copolymers of silicones and polyethers, copolymers of silicones and copolymers of ethylene oxide and propylene oxide and mixtures thereof. The composition of claim 12, characterized in that the nonionic surfactant is selected from the group consisting of copolymers of ethylene oxide and propylene oxide, copolymers of silicones and polyethers, copolymers of silicones and copolymers of ethylene oxide and oxide of propylene and mixtures thereof. The composition of claim 10, characterized in that the filler other than the organic nanoclay is selected from the group consisting of calcium carbonate, precipitated calcium carbonate, colloidal calcium carbonate, calcium carbonate treated with stearate or acid compounds stearic, fumed silica, precipitated silica, silica gels, hydrophobic silicas, hydrophilic silica gels, crushed quartz, ground quartz, alumina, aluminum hydroxide, titanium hydroxide, clay, kaolin, montmorillonite bentonite, diatomaceous earth, iron oxide, carbon black and graphite, mica, talc, and mixtures thereof. 15. The composition of claim 1, characterized in that: the diorganopolysiloxane terminated in silanol (a) has the general formula: MaDbD'c where "a" is 2, and "b" is equal to or greater than 1 and "c" is zero or positive; Month where "x" is 0, 1 or 2 and "y" is either 0 or 1, subject to the limitation that x + y is less than or equal to 2, R1 and R2 each independently is a monovalent hydrocarbon group of up to 60 carbon atoms; D is R SiOtó; wherein R3 and R4 each independently is a monovalent hydrocarbon group of up to 60 carbon atoms; and D 'is wherein R5 and R6 each independently is a monovalent hydrocarbon group of up to 60 carbon atoms; the crosslinker (b) is an alkylsilicate having the formula: (R140) (R150) (R, 60) (R! 70) Si where R14, R15, R16 and R17 are independently selected from monovalent hydrocarbon radicals of up to 60 carbon atoms; the catalyst (c) is a tin catalyst; and, the nanoclay portion of the organic nanoclay (d) is selected from the group consisting of montmorillonite, sodium montmorillonite, calcium montmorillonite, magnesium montmorillonite, nontronite, beidelite, volkonskoite, laponite, hectorite, saponite, sauconite, magadite, kenyaite, sobockite, svindordite, stevensite, vermiculite, halloysite, aluminate oxides, hydrotalcite, illite, rectorite, tarosovite, ledikite, kaolinite and, mixtures thereof, the organic portion of the nanoclay (d) being at least one compound R3R4R5N of tertiary amine and / or compound R6R7R8N + X "of quaternary ammonium wherein R3, R4, R5, R6, R7 and R8 each independently are an alkyl, alkenyl or alkoxy silane group of up to 60 carbon atoms and X is an anion 16. The cured composition of claim 1. 17. The cured composition of claim 9. 18. The cured composition of claim 10. 19. The cured composition of claim 15. The composition of claim 16, characterized in that it exhibits an argon permeability coefficient of no greater that approximately 900 barriers. The composition of claim 17, characterized in that it exhibits a coefficient of permeability to argon of not greater than about 900 barriers. 22. The composition of claim 18, characterized in that it exhibits an argon permeability coefficient of no greater than about 900 barriers. The composition of claim 19, characterized in that it exhibits an argon permeability coefficient of no greater than about 900 barriers.