SILICONE/MULTIFUNCTIONAL ACRYLATE BARRIER COATINGS

Abstract: The invention is a composition made by mixing a multifunctional acrylate with an aminofunctional silane and an ethylenically unsatturated acid to form a reaction product, optionally dissolved in a solvent, characterized in that multifunctional acrylate has a molecular weight of from about 100 to about 3000. The compositon can be coated on a substrate, then optionally exposed to moisture and treated to initiate a free radical reaction. The invention can be applied to a variety of substrates used in packaging applications. The reaction mixture can further be cured by heating in the presence of moisture. The free radical reaction can be initiated by electron beam irriadiation, ultraviolet radiation, gamma radiation, and/or heat and chemical free radical initiators.

Description: SILICOITO/ ULTIFUNCTIONAL ACRYLATE BARRIER COATINGS. Field of the Invention The invention relates to silicone containing compositions and coatings formed therewith having barrier properties which are useful in packaging applications. In another aspects, the invention relates to a method for the manufacture of a coated substrate having barrier properties and to a packaging container. Background of the Invention It is well known that coatings containing silane compounds and itaconic acid improve the gas, oil, and flavor barrier performance of organic polymer film substrates. Moreover, the adhesion of the coating to the film surface, as well as the improved barrier characteristics provided by the silane coating, are greatly enhanced by exposing the coated film to electron beam radiation. A particularly useful barrier composition is descπbed in U.S. Patent No. 5,215,822, which teaches a methanol solution of a vmvl benzvl amrne silane (Dow Corning Corp Z-6032), itaconic acid, and water; coating this solution on a corona treated low density polyethylene film, drying, and then subjecting the coated film to electron beam radiation to graft the coating to the film surface and further improve the barrier properties of the silane coating However, while this coating gives excellent gas barπer properties at low to moderate relative humidity values, the gas permeability increases drastically at very high relative humidity values. The present inventors have surprisingly discovered that the combination of an aminofunctional silane, a multifunctional acrylate and an ethylenically unsaturated acid gives excellent gas barπer propeπies at low to moderate relative humidity values, as well as excellent gas barπer properties at very high relative humidity values. While other patents teach the combination of a mono or multifunctional acrylate with an aminofunctional silane, none teaches the addition of the ethylenically unsaturated acid with an acrylate For example, U.S. Patent No. 5,368,941 teaches a deformable, abrasion-resistant coating formulated from at least one multi-functional acrylate monomer, at least one aminofunctional silane, colloidal silica and at least one acrylate-terminated polyalkylene oxide The acrylate-terminated polyalkylene oxide helps prevent gelling of the coating composition during stripping and also imparts the composition with deformabύity, without sacrificing abrasion resistance. Also, U S. Patent No. 5,434,007 teaches a silane resm coated on a plastic film, where the silane resm is composed of a monofunctional acrylate and an aminofunctional silane. The composition does not utilize a free radical cure, nor does it incorporate the ethylenically unsaturated acid. U S. Patent Nos. 5,260,350 and 5,374,483 relate to a silicone coating composition which, when cured on a solid substrate either by ultraviolet or electron beam radiation, provides a transparent abrasion resistant coating firmly adhered thereon. The silicone coating is prepared by reacting at least one multifunctional acrylate monomer with an amino-organofunctional silane, mixing the modified silane with at least one acrylic monomer and thereafter adding colloidal silica. Again however, neither of these compositions teach the addition of an ethylenically unsaturated acid to achieve barπer properties. JP (Kokai) publication 7-18221 published on January 20, 1995 teaches a surface treatment composition for gas barrier comprising an aminosilane and a compound having an aromatic ring or hydrogenated ring. The present invention is distinguishable, however, because it does not require the addition of cyclic compounds having an aromatic ring. The present invention is distinguishable over each of the above cited prior art because none teach the combination of an aminosilane, multifunctional acrylate and ethylenically unsaturated acid to achieve gas barrier properties. Summary of the Invention The invention is a composition made by mixing in any order a multifunctional acrylate with an amino functional silane and an ethylenically unsaturated acid to form a reaction product, optionally dissolved in a solvent, wherein the multifunctional acrylate has a molecular weight of from about 100 to about 3000, and the aminofunctional silane has at least one molecule of the formula wherein 0 < a < 4 R 1 is independently hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl, acryl, methacryl, alkylaryl, R 2 - SiR m (OR)3-m, or an alkylene Linking group having 2 to 12 carbon atoms connected to one or two nitrogen atoms, with the proviso that at least one R 1 is a hydrogen atom and at least one R 1 is an R 2 - SiR m (OR) 3 - m group, where m is 0, 1 or 2, and R is independently a hydrogen or an alkyl group having from 1 to 6 carbon atoms; R 2 is independently selected from the group consisting of: linear or branched alkylene groups having from 1 to 12 carbon atoms; arylene groups having from 6 to 12 carbon atoms; and linear or branched hydrocarbon groups having from 1 to 16 carbon atoms and at least one alcohol, alcohol ether, ester, amide, urea, thiourea or polyether group. The composition can be coated on a substrate, then optionally exposed to moisture and treated to initiate a free radical reaction. The composition can be applied to a variety of substrates used in packaging applications. The composition can be cured by further heating in the presence of moisture. The free radical reaction can be initiated not only by heating but by electron beam irradiation, ultraviolet radiation, gamma radiation, and/ or heat and chemical free radical initiators. A composition according to the present invention may be employed to provide a barπer layer which improves resistance of the mateπal to transmission of gases and aromas therethrough. For example, a 30 micron uncoated biaxially oπented, corona treated polypropylene film is generally found to have a permeability to oxygen of 1500 cc/m 2 /day as measured at ASTM D3985-81 measured at 80% relative humidity With the present coatings, the oxygen transmission rate of the same film can be reduced to less than 250 cc/m /day as measured at 80% relative humidity. As used herein, the terminology 'improved barπer' refers to a coating which can reduce oxygen transmission rate of the aforementioned uncoated polypropylene film from 1500 cc/m 2 /day to 250 cc/m 2 /day as measured at ASTM D3985-81 measured at 80% relative humidity. Description of the Preferred Embodiments While the invention is susceptible of embodiment in many different forms there is descπbed herein in detail preferred and alternate embodiments of the mvention. It should be understood, however, that the present disclosure is to be considered an exemplification of the principles of the mvention and is not intended to limit the spint and scope of the mvention and /or claims of the embodiments illustrated. Aminofunctional Silanes The aminofunctional silanes are descπbed generally by the formula wherein 0 < a < 4 R 1 is independently hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl, acryl, methacryl, alkylaryl, R 2 - SιR m (OR)3 m , or an alkylene linking group having 2 to 12 carbon atoms connected to one or two nitrogen atoms, with the proviso that at least one R 1 is a hydrogen atom and at least one R 1 is an R 2 - SιR m (OR) 3 m group, where m is O, 1 or 2, and R is independently a hydrogen or an alkyl group having from 1 to 6 carbon atoms; R 2 is independently selected from the group consisting of linear or branched alkylene groups having from 1 to 12 carbon atoms, arylene groups having from 6 to 12 carbon atoms, and linear or branched hydrocarbon groups having from 1 to 16 carbon atoms and at least one alcohol, alcohol ether, ester, amide, urea, thiourea or polyether group. The most preferred aminofunctional silanes useful for the present mvention are N-(2- aπunoethyl)-3-armnopropyltrιmethoxy silane, and aπunopropyltπethoxysilane, and blends thereof. For the purposes of the present invention, the above mentioned amine functional silane group has the general formula In the above formula, R 1 is a monovalent radical mdependently selected from the group consisting of hydrogen; acryl, methacryl, alkyl groups having 1 to 18 carbon atoms, such as methyl, ethyl, propyl, isobutyl, hexyl, octyl, decyl, dodecyl and octadecyl; substituted alkyl having 1 to 18 carbon atoms, such as 3-chloropropyl and 3,3,3-tπfluoropropyl; aryl having 6 to 16 carbon atoms, such as phenyl and naphthyl; substituted aryl having 6 to 30 carbon atoms, such as chlorophenyl, chlorotolyl and dichloroxylyl; arylalkyl having 7 to 9 carbon atoms, such as benzyl, phenethyl and 3-phenylpropyl, and alkylaxyl having 7 to 16 carbon atoms, such as tolyl, xylyl, ethylphenyl and propyltolyl. Accordmg to the invention, at least one R l group is hydrogen. Further, at least one R 1 is an R 2 - SιR m (OR)3 m group, where R is an alkyl group having from 1 to 6 carbon atoms, m is 0, 1 , or 2 and R 2 is defined below The remainmg R 1 groups on the aminosilane are preferably hydrogen or methyl R 1 can also be an alkylene linking group which links two different nitrogen atoms on the same molecule together, thus forming a cyclic aminosilane. The alkylene linking group can also be an arylene group which is connected to two different bonding sites on the same nitrogen atom. The alkylene linking group will have at least 2 carbon atoms and as many as 12 carbon atoms. R 2 is an organic connecting group which provides a separation of at least one carbon atom between the nitrogen atoms or the nitrogen and silicon atoms. Thus, R 2 can be an alkylene group having at least 1 carbon atom or an arylene group having at least 6 carbon atoms Preferably, R 2 is selected from the group consisting of ethylene, propylene, butylene, isobutylene, tπmethylene, tetramethylene, and hexamethylene. In addition, R 2 can contain polar groups such as, linear or branched hydrocarbon groups having from 1 to 16 carbon atoms and at least one alcohol, alcohol ether, ester, amide, urea, thiourea or polyether group. Specific examples of such groups include, those having the general formula - CH 2 CH(OH)(CH 2 ) x -, -CH 2 CH(OH)(CH 2 )x -0-(CH 2 ) , -CH2CH(CH3)C(=0)-0-(CH 2 ) y -, or where x and y are each mtegers from 1 to 12. The hydroxyl and ester groups are highly polar, and it is believed the polar nature of the groups improve barπer properties. Examples of specific amine-containing groups include such structures as -CH CH 2 CH 2 NH 2 , -CH 2 CH 2 CH 2 N(H)CH 2 CH2NH 2) -CH 2 CH2CH 2 N(H)CH 2 CH 2 N(H)CH 2 CH 2 NH 2 , -CH 2 CH 2 CH 2 CH 2 NH 2 , -CH 2 CH 2 CH 2 CH 2 CH NH 2 , -CH 2 CH 2 CH 2 N(H)Me, -CH 2 CH 2 CH 2 N(H)CH 2 CH 2 NMe 2> -CH 2 CH 2 CH 2 N(H)Et, -CH 2 CH 2 CH 2 N(Et)H, -CH 2 CH(CH 3 )CH 2 N(H)CH 2 CH 2 NH 2 and -CH 2 CH(CH3)C__2NH 2) inter alia, wherein Me and Et denote methyl and ethyl, respectively. A specific example of an amine containing cyclic group is piperazine. As used herein the term "aminofunctional silane' can mean a single species of the formula descπbed above, such as N-(2-aιnιnoethyl)-3-ammopropyltπmethoxy silane, or it can mean mixtures or one or more species of aminofunctional silanes, such as N-(2-amιnoethyl)-3- ammopropyltπmethoxy silane and aimnopropyltπethoxysilane. The above descπbed aminofunctional silanes can be prepared by methods known to those skilled in the art, and which are amply descπbed in the chemical literature. Multifunctional Acrylates The multifunctional acrylates of the present mvention are defined as acrylates having, on average, greater than two functional acrylate groups per molecule and a molecular weight of from about 100 to about 3000. Multifunctional acrylates are prefeπed over monofunctional acrylates because monofunctional acrylates do not form flexible, crack free coatings as do the multifunctional acrylates. The majoπty of multifunctional acrylates commercially available can be used, but it is the smaller, more compact, i.e., proportionally more reactive acrylates that give the best results. The multifunctional acrylates are preferably selected from the group consisting of acrylated polyols with molecular weights of from about 150 to about 600; polyester urethane acrylates with molecular weights of from about 1000 to about 2000; polyether acrylates with molecular weights from 200 to 1500; polyurethane acrylates with molecular weights of from about 400 to about 2000; polyurea acrylates w th molecular weights of from about 400 to about 2000, epoxy acrylates w th molecular weights of from about 300 to about 1000; and mixtures of multifunctional acrylates thereof. Most prefeπed acrylates are pentaerythπtol tetraacrylate; an acid functional acrylate; polyester terra acrylate; polyether tetra acrylate; an aliphatic urethane acrylate, Ebecryl 1290; ditπmethylolpropane tetra acrylate; an ethoxylated tπmethylol propane tπacrylate, Ebecryl 160. Other preferred acrylate include glycerol tπacrylate, tπacrylate ester of tπs-[z-hydroxy-ethyl] isocyanurate, hexane dioldiacrylate, and dipentaerythπtol hexacrylate. Ethoxylated and propoxylated versions of these acrylates may be used in this invention. These acrylates and methods of their production are well know m the art, and available commercially from such companies as UCB Radcure, (Brussels, Belgium) and Sartomer Corp. (Philadelphia, Pa.) As used herein, the term "mixtures of multifunctional acrylates" means mixtures of different acrylates of the same species, such as two different epoxy acrylates, or mixtures of different species of acrylates, such as epoxy acrylates and urethane acrylates. Ethylenically Unsaturated Acid In addition to the aminosilane and the multifunctional acrylate, a quantity of an ethylenically unsaturated acid is added to the composition. By "ethylenically unsaturated acid" it is meant any acid which has vmyl unsaturation. It is believed that the ethylenically unsaturated acid substantially improves the oxygen barrier performance of the composition because the carboxylic group forms an amine salt with amino groups of the aminosilane, which contributes significantly to the coating's barrier properties. The ethylenically unsaturated acid is likely to be added in the amount of at least 5 to about 60 parts by weight of the composition, with about 30 to about 50 parts by weight being most preferred. The most preferred ethylenically unsaturated acids used in the present invention are dicarboxylic (i.e. have two carboxylic acid groups) or monoalkylester thereof and the most prefeπed is itaconic acid; however, other acids such as fumaric, maleic, citraconic, methacrylic, acrylic, sorbic, cinnamic, vinyl sulfonic acid, mesaconic acid, and itaconic acid monomethylester may also be used. The term "ethylenically unsaturated acid" as used herein includes mixtures of one or more of the aforementioned acids. Solvents The components of the present invention can optionally be reacted together in a solvent. In general, water, alcohols and blends thereof will serve as suitable solvents because the multifunctional acrylate and the ethylenically unsaturated acid are soluble therein. Typically, the solvent is a water/ alcohol mixture where the alcohol is present in an amount of about 1- 99%. In addition, the selected solvent must wet the substrate. Preferably, the solvent will be nontoxic, and will not extend the drying time of the coating beyond what is commercially acceptable. The amount of solvent can range from about 20 to about 99 parts by weight and is preferably from about 60 to about 95 parts by weight of the total composition. Preferred solvents are methanol, ethanol, n-propanol, isopropanol, butanol, and l-methoxy-2-propanol (available as "Dowanol PM" from the Dow Chemical Co., Midland, MI). Critical Ratios During the reaction of aminosilanes with multifunctional acrylates, it is possible to utilize an excess of multifunctional acrylate over and above that required to react with the amino nitrogen atoms. In multifunctional acrylates, such as pentaerythritol tetraacrylate, the amine chains attached to the trimethoxysilyl groups may also have pendent acrylate groups which will undergo further polymerization under the influence of ionizing radiation. It is believed that the acrylate groups of the multifunctional acrylate and the amino groups of the aminofunctional silane undergo an addition reaction (Michael Addition) readily upon mixing of these two components. In addition, hydroxyl groups and solvents present may interact with alkoxy groups attached to the silicone atoms of the aminofunctional silane and cause a thickening of the composition at certain concentrations of the components in the solvent. For example, one may employ an "amine rich" system, in which the total number of amine functional sites in the composition due to the aminofunctional silane can be up to about six (6) times greater than the total number of acrylate sites in the composition due to the multifunctional acrylate, i.e., the ratio of amine functionality to the acrylate functionality can be from about 6: 1 to about 1: 1, with a ratio of about 4: 1 to about 1: 1 being prefeπed, and with a ratio of 2.1 bemg most prefeπed. In the case where the aminofunctional silane is N-(2- ammoethyl)-3-amιnopropyltπmethoxy silane or ammopropyltπethoxysilane, and the multifunctional acrylate is pentaerythπtol tetraacrylate, the ratios m the amine πch system can be expressed in terms of molar ratios, with the prefeπed molar ratio of aminosilane to multifunctional acrylate bemg from about 6: 1 to about 1.1, with a molar ratio of about 4.1 bemg most prefeπed. Excellent results can also be achieved usmg an 'acrylate πch" system, where the total number of reactive nitrogen sites m the composition from the aminofunctional silane is up to about six (6) times less than the total number of reactive acrylate sites in the composition due to the multifunctional acrylate, i.e., the ratio of amine functionality to acrylate functionality can be from about 1 1 to about 1.6, with a range of about 1.3 bemg prefeπed. In the case where the aminofunctional silane is N-(2-armnoethyl)-3-aπunopropyltr methoxy silane or aminopropyltπethoxy silane, and multifunctional acrylate is pentaerythπtol tetraacrylate, the ratios of the acrylate πch system can be expressed m terms of molar ratios, with the prefeπed molar ratio of aminosilane to multifunctional acrylate bemg from about 1.1 to about 1.3, with a molar ratio of about 1.1.5 being most prefeπed. Although the order of addition of the components to provide a composition according to the present invention is not cπtical, certain methods are preferable For example, the aminofunctional silane and the acrylate component can be added together to form a Michael Adduct, before the addition of the ethylenically unsaturated acid. Also, the ethylenically unsaturated acid may be added at some point after the Michael Addition reaction begins, but before the aminosilane and/or the acrylate are completely consumed. "Quenching' the reaction by adding the ethylenically unsaturated acid can occur at any point in the reaction process, i.e., the acid mav be added to the aminosilane before any acrylate is added, or after most of the acrylate is added. Practically, the reaction may be quenched at a predetermmed pomt by simply adding part of the acrylate to the aminosilane, then addmg the rest of the acrylate and the acid to this mixture. It is prefeπed that the quenchmg technique be used with the amine πch formulations of the invention. Coat Weight The coating can be applied in any desired amount, however, it is prefeπed that the coating be applied in an amount of from about 0.05 to about 20 gms/m 2 , the prefeπed coating weight bemg from about 0 5 to about 10 gms/m 2 Coating weight can be determined by gravimetπc compaπson. The coating can be applied to the substrate by any conventional method, such as spray coating, roll coating, slot coating, meniscus coating, immersion coating, and direct, offset, and reverse gravure coatmg Substrates The coating can be disposed on a wide vaπety of substrates, including, but not limited to polyolefins, such as oriented polypropylene (OPP), cast polypropylene, polyethylene and polyethylene copolymers, polystyrene, polyesters, such as polyethylene terephthalate (PET), or polyethylene naphthalate (PEN), polyolefin copolymers, such as ethylene vinyl acetate, ethylene acrylic acid and ethylene vinyl alcohol (EVOH), polyvinylalcohol and copolymers thereof, polyamides, such as nylon, and MXD6, polyimides, polyacrylonitrile, polyvinylchloride, polyvinyl dichloride, polyvinylidene chloride, and polyacrylates, ionomers, polysaccharides, such as regenerated cellulose, and silicone, such as rubbers or sealants, other natural or synthetic rubbers, glassine or clay coated paper, paper board or craft paper, and metallized polymer films and vapor deposited metal oxide coated polymer films, such as A10 x , SiO x , or TiO x . The aforesaid substrates are likely to be in the form of a film or sheet, though this is not obligatory. The substrate may be a copolymer, a laminate, a coextruded, a blend, a coating or a combination of any of the substrates listed above according to the compatibility of the materials with each other. In addition, the substrate may be in the form of a rigid container made from materials such as polyethylene, polypropylene, polystyrene, polyamides, PET, EVOH, or laminates containing such materials. The aforesaid substrates may also be pretreated prior to coating by corona treatment, plasma treatment, acid treatments and flame treatments, all of which are known in the art. In addition, the compositions of the present invention can be used for a wide variety of packaging containers, such as pouches, tubes, bottles, vials, bag-in-boxes, stand-up pouches, gable top cartons, thermo-formed trays, brick-packs, boxes, cigarette packs and the like. In addition, the compositions of the present invention may be used as a laminating adhesive. Of course, the present invention is not limited to just packaging applications, and may be used in any application wherein gas, or aroma barrier properties are desired, such as tires, buoyancy aides, inflatable devices generally, etc. Any of the foregoing substrates may have a primer or primers applied thereon. The primers are applied to the substrates by methods known in the art such as spray coating, roll coating, slot coating, meniscus coating, immersion coating, and indirect, offset, and reverse gravure coating. Suitable primers include, but are not limited to carbodiimide, polyethylenimine, and silanes, such as N-(2-arninoethyl)-3-arninopropyltrirnethoxy silane and aminopropyltriethoxysilane. Curing While the compositions of the present invention will form films at ambient conditions, optimum results are achieved by heating and/or free radical cures. Generally, the higher the temperature, the faster the coating will solidify. The upper limit to the heating is the temperature at which the substrate will undergo unacceptable distortion. Also, heating will accelerate the rate of hydrolysis of silicon /alkoxy groups and also the rate of condensation of the silicon bonded alkoxy groups with silicon bonded hydroxy groups to form silicon-oxygen- silicon groups. The composition may be dried at room temperature or in an oven at temperatures up to about 140°C, with temperatures of from about 60°C to about 120°C being prefeπed and temperatures of about 90°C to about 110 C C being most prefeπed. Heating time is temperature dependent and the coating will reach tack free time in one to 10 seconds. The heating step serves to evaporate the solvent when used and accelerate the condensation reaction between Si-OH groups and SiOH/SiOH groups. The compositions may be further cured by initiating a free radical reaction. The most prefeπed method of initiating the free radical reaction is through the use of electron beam radiation, although ultraviolet or free radical generators such as azo compounds and peroxides may also be used. The compositions are preferably cured by a free radical generator, such as ultraviolet, electron beam, or gamma radiation or chemical free radical generators such as azo compounds and peroxides. Low energy election beam iπadiation is the preferred method of curing because it is cheaper than gamma sources like Cobalt M-60. Its advantage over ultraviolet radiation as a cure system lies in its ability to generate free radicals without photoinitiators. It also imparts higher yields of crosslink density and chemical grafting of the coating to the substrate. Electron beam accelerators of various types such as van de Graaf-type, resonance transformer-type, linear-type, dynamatron-type and high frequency-type can be used as a source of electron beam. Electron beam having energy of from about 5 to about 2000 KeV, preferably from about 50 to about 300 KeV discharged therefrom may be iπadiated in a dose of from about 0.1 to about 10 Mrads (MR). Low electron beam voltages (less than 20 KeV) may be used if the substrate is treated in a vacuum. Commercially available sources of electron beam are Electro Curtain CB-150 available from Energy Sciences, Inc. (Wilmington, MA). The compositions may also be ultraviolet light cured if one or more photoinitiators is added prior to curing. There are no special restrictions on the photoinitiators as long as they can generate radicals by the absorption of optical energy. Ultraviolet light sensitive photoinitiators or blends of initiators used in the UV cure of the present composition include 2-hydroxy-2-methyl-l- phenyl-propan- 1-one (Darocure 1173), sold by EM Chemicals, and 2,2 Dimethoxy-2-phenyl- acetol-phenone (Irgacure 651), sold by Ciba-Geigy Corporation, Hawthorne, New York. For purposes of this invention, it has been found that from about 0.05 to about 5 weight percent based on the total solids in the composition, of the photoinitiators described herein will cause the composition to cure. In addition to radical polymerization and grafting to crosslink the coating after it has been applied to the substrate, it is possible to further crosslink the composition utilizing acid catalyzed condensation reactions. In this reaction, a methoxylated active hydrogen compound, such as trimethylol phenol, or a mixture of formaldehyde with aldehydes, ketones, and other active hydrogen compounds react with amine salts, such as the itaconate salts of the amine silanes or derivatives to form alkylated amines. Preferred Embodiments To prepare the prefeπed embodiment of the invention, the acrylate component, preferably pentaerythπtol tetraacrylate (PETA), is dissolved m a solvent such as Dowanol PM. The silane, preferably N-(2-amιno ethyl) gamma aminopropyl tnmethoxysilane is added to the acrylate solution so that the molar ratio of aminosilane to acrylate is about 4.1. This mixture is allowed to equilibrate for one hour at ambient conditions. Itaconic acid, m an amount of about 1.3 moles per gram atom of nitrogen is then added to the equilibrated solution. The coating solution is applied to corona treated 30 micron thick 'RAYOPP" oπented polypropylene film from UCB Films. The coated film is placed immediately m an oven maintained at about 80- 100°C and held there for about 10 minutes. The oven is maintained at a relative humidity of about 50%. The dπed coated film is then "cured" by an electron beam dose of 10 Mrads at 170 kV. Optional Additives Vaπous optional additives can be added to the composition to improve vanous properties. These additives may be added as desired and m any amount as long as they do not reduce the performance of the barπer coatings as illustrated herein. Examples of additives include additional additives as earlier descπbed, antiblock and slip aides such as stearamide, oleamide or polar additives, such as epoxides, polyols, glycidols or polyamines, such as polyethylenimine, and other silanes may be added. Specifically excluded from the scope of the present mvention are colloidal silicas and silanes or other molecules having four alkoxy or other hydrolyzable groups disposed on a single silicone or other organometallic atom, such as tetra ethoxy silane, and the like Wetting agents, such as a polyethoxylated alkyl phenol may also be added. Examples Experiments 1- 10 illustrate the utility of a mixture of itaconic acid with the Michael addition product of vaπous acrylate esters with N-(2-amιno ethyl)gamma aminopropyl tnmethoxysilane, hereinafter refeπed to as Z-6020, as a gas barπer coating on polypropylene film. In experiments 1-12 the Z-6020, acrylate ester, and itaconic acid were utilized m a molar ratio of 4.1: 10 4 with a total solids content of 34 grams / 104 grams of solution. The solvent employed in all the experiments descnbed below was l-methoxy-2-propanol, available commercially from Dow Chemical Company (Midland, MI) as 'Dowanol PM" The Z-6020 was obtained from Dow Corning Corporation (Midland, MI) and the itaconic acid from Aldπch Chemical Company (Milwaukee, WI) The coating solutions were all applied to corona treated 30 micron thick "RAYOPP" oπented polypropylene film from UCB Films utilizing a #12 Myers rod. The coated film was placed immediately in a laboratory oven maintained at 80-100°C and held there for 10 minutes. Two open pans of water placed on the bottom shelf of the oven maintained a relative humidity of about 50% The heated coated film was then cured" by an electron beam dose of 10 Mrads at 170 KeV The oxygen permeability values for each film were measure and recorded in units of cc/ square meter per 24 hours, "dry" values bemg measured at 0% relative humidity using a MOCON Oxtran Model 100 and "wet" values at 80-82% relative humidity utilizing a MOCON Model 2/20 MH. The MOCON instruments were obtained from Modern Controls Corporation. For companson, the polypropylene base film had a permeability of about 1500cc/ square/meter 24 hours. Experiment 1 A solution of 3.777 g. of "Ebecryl 770", a monofunctional polyester acrylate with a reported molecular weight of 280, obtained from UCB Radcure, m 70 g. of Dowanol PM was prepared and 11.982 g. of Z-6020 was added with stirπng. After one hour at ambient temperature, 18.241 g. of itaconic acid was added and stirred to dissolve. While measuring the dry permeability, the sample developed numerous cracks, which made the coating unsuitable for use as a barner film. Experiment 2 A solution of 9 744 g. of "Ebecryl 810", polyester tetra acrylate w th a reported molecular weight of 900 obtained from UCB Radcure, was prepared in 70 g. of Dowanol PM. and 9.615 g. of Z- 6020 was added. After standmg at ambient temperature for one hour, 14.641 g. of itaconic acid was added and stiπed to dissolve. After coating, drying and cuπng the dry permeability was 12.5cc and the wet permeability was 259cc. Experiment 3 A solution of 8.782 g of "Ebecryl 1290", an aliphatic urethane acrylate having six acrylate groups per molecule with a reported molecular weight of 780, obtained from UCB Radcure, was prepared in 70 g. of Dowanol PM, and 9.996 g. of Z-6020 was added with stirring. After standmg at ambient temperature for one hour, 15.222 g. of itaconic acid was added and stirred to dissolve. After coating, drying and curing, the permeability was 5.23cc dry and 38cc wet. Experiment 4 A solution of 5.885 g. of "Ebecryl 140", ditrimethylolpropane tetra acrylate, reported molecular weight 466, obtained from UCB Radcure, was prepared in 70 g. of Dowanol PM. To this solution was added 11.159 g. of Z-6020 and after standmg one hour at ambient temperature, 18.285 g. of itaconic acid was added and stoned to dissolve. In this experiment, 11.2 moles of itaconic acid was employed and the solids were 35.299 g. m 105.299 g. of solution. After coating, drying and cuπng, the permeability was 1. Ice dry and 15 lec wet. Expenment 5 A solution of 5.454 g. of "Ebecryl 160", an ethoxylated tnmethylol propane tπacrylate with a reported molecular weight of 428 obtained from UCB Radcure, in 70 g. of Dowanol PM was prepared and 11.315 g. of Z-6020 was added. After standmg one hour at ambient temperature, 17.231 g. of itaconic acid was added and stiπed to dissolve. After coating, drying and cuπng the permeability was 0.1 dry and 154 wet. Experiment 6 A solution of 5.454 g. of "SR 9020", a propoxylated glyceryl tπacrylate with a reported molecular weight of 428, obtained from Sartomer Corporation, was prepared m 70 g. Dowanol PM, and 11.315 g. of Z-6020 was added. After standing one hour at ambient temperature, 17.231 g. of itaconic acid was added and stiπed to dissolve. After coating, drying and curing the dry permeability was 0.5cc and the wet permeability was 102cc. Experiment 7 A solution of 10.492 g. of "Ebecryl 80", a polyether tetra acrylate with a reported molecular weight of 1000, obtamed from UCB Radcure, was prepared in 70 g. of "Dowanol PM" and 10.492 g. of Z6020 was added. After standing one hour at ambient temperature, 14.188 g. of itaconic acid was added and stiπed to dissolve. After coating, drying, and cuπng the dry permeability was 6.3cc and the wet permeability was 224cc. Experiment 8 A solution of 6.457 g. of "Ebecryl 3720", an epoxy diacrylate with a molecular weight of 525, supplied by UCB Radcure, was prepared in 70 g of "Dowanol PM" To this solution was added 10.921 g. of Z-6020, and after standmg at ambient temperature for one hour, 16.622 g. of itaconic acid was added. After coating, drying, and cuπng the dry permeability was 0.2cc and the wet permeability was 62cc. Experiment 9 A solution of 5.399 g. "SR 360", the tnacrylate ester of tπs (2-hydroxy ethyl) isocyanurate, molecular weight 423, supplied by Sartomer Company, was prepared m 70 g. of Dowanol PM. To this solution was added 11.339 g. of Z-6020, and after standmg one hour at ambient temperature, 17.262 g. of itaconic acid was added and stiπed to dissolve. After coatmg, drying, and cuπng the dry permeability was 0.3cc and the wet permeability was 55cc. Experiment 10 A solution of 10.492 g. of "Ebecryl 220", an aromatic urethane hexaacrylate ester with a reported molecular weight of 1000, supplied by UCB Radcure, was prepared m 70 g. of Dowanol PM and 9.139 g. of Z-6020 was added. After standing at ambient temperature for one hour, 14.188 g. of itaconic acid was added and stiπed to dissolve. After coating, drying, and curing the dry permeability was 3.6cc and the wet permeability was 144cc. Expenments 11- 13 illustrate the effectiveness of the mixture of itaconic acid with Michael addition product of gamma aminopropyl tπethoxysilane with vaπous acrylate esters m providing barπer coatings on polypropylene film. The molar ratio of silane -.acrylate esteπitaconic acid in these experiments was 4: 1:8. The substrate as well as the coating, drying and cuπng conditions were the same as those used in Expenments 1- 12 and which are descnbed above. Experiment 11 A solution of 5.260 g. of "SR 295", pentaerythπtol tetraacrylate, calculated molecular weight of 352, supplied by Sartomer Company, was prepared m 70 g. of Dowanol PM and 13.206 g. of gamma aminopropyl tπethoxy silane, supplied by Union Carbide Corporation (Danbury, CT) as "A-l 100", was added. After standmg at ambient temperature for one hour, 15.534 g. of itaconic acid (obtamed from Aldπch Chemical Corp ) was added and stirred to dissolve. After coating, drying and cunng the dry permeability was 2.9cc and the wet permeability was 235cc. In a 250 ml beaker was prepared a solution of 4.863 g. of pentaerythπtol tetraacrylate in 70 g. of dry isopropanol and 12.21 g. of gamma-aminopropyl tπethoxysilane, (A- 1100, obtamed from Union Carbide Corporation) was added and the solution was allowed to stand overnight at ambient temperature. A quantity of 12.927 g. of itaconic acid was added and the mixture was stiπed to obtain a clear solution A 25 weight percent solids solution was prepared by adding 10 g of isopropanol to 50 g of the above solution. After coating, drying and cunng, the dry permeability was 0.2cc and the wet permeability was 88cc. The dry coat weight was 2.9 g./ square meter. In a 250 ml beaker, a solution of 3.822 g of pentaerythπtol tetraacrylate in 70 g of isopropanol was prepared, and 11.505 g of N-(gamma tπmethoxysilylpropyl) diethylenetnamine supplied by OSI as A- l 130 was added w th stirπng. The solution was maintained at ambient temperature overnight, and 14 673 g. of itaconic acid was added. The grey precipitate was stiπed until a clear solution was obtamed. The solution was diluted to 25 weight percent solids usmg dry isopropanol, coated and cured as descπbed. The dry coat weight was 3 15 g /square meters, the dry permeability was o. Ice and the wet permeability was 44cc. In a 250 ml beaker a solution of 3.381 g of pentaerythπtol tetraacrylate in 70 g of isopropanol was prepared, and 14 847 g of bis- (gamma tnmethoxysilylpropyl) amine (A- 1170, supplied by Osi) was added with stirπng. The solution was maintained at ambient temperature overnight, then 11.322 g. of itaconic acid was added and stiπed until a clear solution was obtained The solution was diluted to 25 weight percent solids with dry isopropanol, coated, dned and cured. The dry coat weight was 2.8 grams/ square meter; the dry permeability was 1.96 cc and the wet permeability was 82cc. Expenment 12 A solution of 11.628 g of "Ebecryl 220" (descπbed in Experiment 10) was prepared in 70 g. of Dowanol PM, and 10 278 g of A- 1100 (as descnbed in Expenment 11) was added. After standmg for one hour at ambient temperature, 12.094 g. of itaconic acid was added and stiπed to dissolve. After coating, drying and cuπng, the dry permeability was 4 4cc and the wet permeability was 58cc. Experiment 13 A solution of 7.398 g. of "Ebecryl 40", a tetra functional acrylate ester with a reported molecular weight of 535, supplied by UCB Radcure, was prepared in 70 g. of Dowanol PM. To this solution was added 12.223 g. of A-l 100, and after standing at ambient temperature for one hour, 14.379 g. of itaconic acid was added and stiπed to dissolve. After coating, drying and curing, the dry permeability was 0.2cc and the wet permeability was 112cc. Experiments 14 and 15 demonstrate the effectiveness of the Michael addition products from Z- 6020 and mixtures of acrylate esters combined with itaconic acid in a molar ratio of 4: 1: 10.4 (silane:acrylate:acid) producing barrier coatings for polypropylene film. Experiment 14 A solution of 2.309 g. of "SR 295" (described in Experiment 11) and 5.246 g. of "Ebecryl 220" (described in Experiment 10) was prepared in 70 g. of Dowanol PM. A total of 10.484 g. of Z- 6020 was added, and after standing one hour at ambient temperature, 15.901 g. of itaconic acid was added and stiπed to dissolve. After coating, drying, and curing, the dry permeability was 0. Ice and the wet permeability was 16cc. Experiment 15 A solution of 2.309 g. of "SR 295" (described in Experiment 11) and 2.854 g. of "SR238", hexanediol diacrylate, molecular weight 226, was prepared in 70 g. of Dowanol PM. A total of 11.432 g. of Z-6020 was added, and after standing at ambient temperature for one hour, 17.404 g. of itaconic acid was added. After coating, drying and curing, the dry permeability was 0.05cc and the wet permeability was 22cc. Experiment 16 illustrates the effectiveness of the Michael addition products of mixtures of A- 1100 and Z-6020 with acrylate esters, combined subsequently with itaconic acid in producing barrier coatings for polypropylene film in a molar ratio of 4: 1: 10.4 for Z-6020:acrylate:itaconic acid. Experiment 16 A solution of 4.621 g. of pentaerythritol tetra acrylate "SR 295", (described in Experiment 11) was prepared in 70 g. of Dowanol PM, and 5.824 g. of Z-6020 and 5.807 g. of A- 1100 were added. After standing for one hour at ambient temperature, 17.740 g. of itaconic acid was added. After coating, drying, and curing the dry permeability was 0.05cc and the wet permeability was 27cc. Experiment 17 illustrates that an aminosilane/ acrylate ester Michael addition product in a molar ratio of 4: 1 without added itaconic acid will provide a barrier coating on polypropylene film, but that the barrier properties are greatly enhanced by the addition of itaconic acid (see Experiment 10, where the same components were used but itaconic acid was included). Expenment 17 A solution of 10.492 g. of "Ebecryl 220", (descπbed in Expenment 10), was dissolved in 70 g. of Dowanol PM, and 9.319 g. of Z-6020 was added. After standing for one hour at ambient temperature, the mixture was coated on polypropylene film, dned, and cured. The dry permeability was 380cc and the wet permeability was 294cc. Expenment 18 illustrates that the concentration of the solids in the coating solution affects the permeability of the resulting coated film. Expenment 18 A 40 weight percent solids solution of the Michael addition product of Z-6020 and pentaerythπtol tetraacrylate with the proper quantity of itaconic acid to provide a molar ratio of 4 10.4 (silane.acrylate.itaconic acid) was prepared by dissolving 5.432 g. of "SR 295" in 60 g of Dowanol PM, and then addmg 13.704 g. of Z-6020. After one hour, 20.364 g. of itaconic acid was added and stirred to dissolve. Coated samples were prepared using a #12 Myers Rod. The 40 weight % solution was coated directly, and 20 and 10 weight % solids solutions were prepared by dilution of the 40% solution with Dowanol PM. The permeabilities are descπbed below. Coating Dry Permeability Wet Permeability 40% 0.15 cc 7.8 cc 20% 1.6 cc 32 cc 10% 45 cc 311 cc Experiment 19 illustrates that a mixture of Z-6020 and itaconic acid without the addition of an acrylate ester can be used as a barπer coating for film, but that the coatmg cracks and is undesirable as a barner film. Experiment 19 A solution of 7.83 g. of Z-6020 was prepared in 35 g. of Dowanol PM, and 9.17 g. itaconic acid was added and stiπed to dissolve. After coating, drying, and cunng the coating appeared to be somewhat bnttle; a sample exhibited many small cracks rendering it unsuitable for use as a barπer film. Expenment 20 Illustrates that barner coatings can be prepared usmg simple mixtures of Z-6020, acrylate esters, and itaconic acid These results show that allowing the Michael addition to proceed before adding the itaconic acid is an optional requirement. Experiment 20 A solution of 15.395 g. of "SR 295" (descnbed in Expenment 11), was prepared in 70 g. of Dowanol PM, and then 12.131 g. of itaconic acid was added and stured to dissolve, and 6.46 g. of Z-6020 was added. The solution was coated immediately, and after drying and cunng, the dry permeability was 14cc and the wet permeability was 26cc. The effect of dose and voltage of the electron beam on the permeability of a barπer coating is illustrated in Expenment 21. Expenment 21 A solution of 30.79 g. of "SR 295", (descnbed in Expenment 11), was prepared in 112 g. of Dowanol PM, and 12.948 g. of Z-6020 was added. After standing at ambient temperature for one hour, 24.262 g. of itaconic acid and 28 g. of Dowanol PM was added and stiπed to dissolve. After coating and drymg, the samples were subjected to the electron beam at the conditions descnbed below in Table 1 and the following results were obtained. Table 1 Dose Optimization Permeability iOppm [0 2 ] Voltaee, KeV Dose, Mrads Dry Wet 125 2.5 35 197 125 5.0 19 131 125 10.0 6 50 150 2.5 21.0 134 150 5.0 5.1 35 150 10.0 5.5 23 170 2.5 25 161 170 5.0 31 140 170 10.0 17 55 Air 170 2.5 36.5 209 170 5.0 15 30 170 10.0 29.5 44 Experiment 22 Expenment 22 illustrates the effect of electron beam doses and voltage on another representative barπer coating composition. A solution of 9.234 g. of "SR 295" was prepared in 120 g. of Dowanol PM, and 23.296 g. of Z-6020 was added. The solution was allowed to stand at ambient temperature for 24 hours, then 35.468 g. of itaconic acid and 20 g. of Dowanol PM were added and stiπed to dissolve After coatmg and drying, the samples were subjected to the electron beam conditions descπbed in Table 2 below and the following results were obtained. Table 2 Dose Optimization Permeability Voltage, KeV Dose, Mrads Dry Wet 125 2.5 0.03 48 125 5.0 0.06 148 125 10.0 0.05 67 150 2.5 0.03 86 150 5.0 0.65 97 150 10.0 002 67 170 2.5 0.3 43 170 5.0 0.1 95 170 10.0 0.1 116 170 2.5 0.09 84 170 5.0 0.2 212 170 10.0 0.3 87 Expenment 23 Vaπous additives can be included in the compositions of the present invention to achieve improved barπer properties. Table 3 illustrates the effect of adding epoxy functional additives such as glycidyl methacrylate, glycidol, ethylene glycol diglycol ether and bisphenol A to the composition compnsmg Z-6020, pentaerythntol tetraacrylate, and itaconic acid. The order of addition of each component is listed, and the components were added sequentially in the appropπate molar ratios as shown As can be seen, the additional additives can improve the barner properties of the film at high humidity Expenment 24 As seen m Table 4, the coated films can give excellent barner properties if the substrate is pruned pπor to the application of the coating. The pruning solutions were prepared by weighing out the required quantity of primer mateπal and diluting it with the required amount of the appropnate solvent as recited in Table 4 For example, a 0 1 percent polyethylene lmine was added to 300 g of isopropanol in a 600 ml beaker, and stiπed to obtain a clear solution. The film substrates were pπmed by immersing the film in the pπmer solution which was contained in a shallow plastic tray. The film was agitated to ensure complete coverage by the primer solution, then it was drained and hung vertically to allow the excess pπmer solution to drain completely and allow the solvent to dry at ambient temperature. Expenment 25 As illustrated in Table 5, the excellent barπer properties can be achieved by the addition of a polyoxyethvlated alkyl phenol to the coating solution pnor to application of the coating solution to the substrate The wettmg agent employed in the expenments descπbed in Table 5 was Eccoterge EO-100", a polvethoxylated alkyl phenol supplied by Eastern Color and Chemical Co The mdicated quantity of wetting agent was added to each solution by prepaπng the coating solution at 30 weight present solids m isopropanol and diluting this solution to 15 weight percent solids with isopropanol containmg the quantity of wetting agent required to provide the amount indicated Expenment 26 The data in Table 6 illustrate that other compounds such as a carbodiimide (Union Carbide Corp , Danbury, Ct.) can be used as a pπmer for coating compositions of the present mvention, and that compositions utilizmg an added wetting agent can be successfully applied to pπmed film The procedures followed for adding the wetting agents and applying the primers were the same as those followed for Experiments 24 and 25 Expenment 27 As seen in Table 7, additional additives and primers can be combmed to achieve better barπer properties The procedures followed for applying the wetting agents and primers were the same as those followed for Expenments 24 and 25. Table 3 All solutions were prepared at 30% solids in isopropyl alcohol, (except TR-295 and TR-296, which were prepared at 15% solids in isopropyl alcohol) and the amounts of the components are expressed in molar ratios in parentheses next to the components listed. EB conditions : 170 KeV, 10 Mrads. *P=PETA, IA or ITA=ITACONIC ACID, Z=Z-6020, GM=GLYCIDYL METHACRYLATE, G=GLYCIDOL, E=EPOXY. The letters are written in the order of addition of the components in the solutions. NM means "not measured". Sample # Composition Addition Coat weight OTR 0% OTR 80% RH order (g/m a ) RH TR-295 Z-6020/PETA/ITA (4: 1: 10.4), 15% Solids 3.5 0.2 160 TR-296.1R Z-6020/PETA/ITA (1: 1.5:3.2), 25% Solids Effects of the addition order TR-297 Z-6020/Glycidyl methacrylate/PETA/ITA(4: l: l : 10.4) GM+Z+P+1A NM NM 132.5 TR-298 Z-6020/Glycidyl methacrylate/PETA/ITA(4: 1 : 1 : 10.4) P+Z+GM+IA 3.5 0.10 94 TR-299 Z-6020/Glycidyl methacrylate/PETA/lTA(4: 1 : 1 : 10.4) P+Z+1A+GM NM 0.25 150 TR-300 Z-6020/Glycidyl methacrylate/PETA/ITA(4: 1: 1: 10.4) GM+Z+IA+P 3.7 14.4 169 Effects of the 6020 /epoxy ratio TR-305 Z-6020/Glycidyl methacrylate/PETA/ITA(4:2: 1 : 10.4) GM+Z+P+IA NM >500 NM TR-306 Z-6020/Glycidyl methacrylate/PETA/ITA(4:2: l : 10.4) P+Z+GM+IA NM 0.05 17 TR-307 Z-6020/Glycidyl methacrylate/PETA/ITA(4:2: l : 10.4) P+Z+IA+GM 2.7 0.2 42 Sample # Composition Addition Coat weight OTR 0% OTR 80% RH order lR/m a ) RH TR-308 Z-6020/Glycidyl methacrylate/ PETA/ ITA(4:2: 1 : 10.4 GM+Z+IA+P 2.7 >500 NM TR-321 Z-6020/Glycidyl methacrylate/PETA/ITA(4:3: 1 : 10.4 Z+IA+P+GM NM 0.1 39 TR-322 Z-6020/Glycidyl methacrylate/PETA/ITA(4:3: 1 : 10.4 Z+1A+GM+P 2.7 0.22 41 TR-323 Z-6020/Glycidyl methacrylate/PETA/lTA(4:4: 1 : 10.4 Z+IA+P+GM NM 0.2 45 TR-324 Z-6020/Glycidyl methacrylate/PETA/ITA(4:4: 1 : 10.4 Z+1A+GM+P 2.5 7.1 75 TR-332 Z-6020/Glycidyl methacιylate/PETA/ITA(4:5: 1: 10.4 Z+P+GM+IA 3.4 0.1 16.5 TR-333 Z-6020/Glycidyl methacrylate/PETA/ITA(4:6: 1: 10.4 Z+P+GM+IA NM 0.2 44.5 TR-309 Z-6020/Glycidyl methacιylate/PETA/ITA(4:2:6: 12.8 GM+Z+P+IA 2.45 22 79 TR-31 1 Z-6020/Glycidyl methacrylate/PETA/ITA(4:2:6: 12.8 P+Z+IA+GM 3.8 13.2 61 TR-336 Z-6020/Glycidyl methacrylate/PETA/ITA(4:3:6: 12.8 GM+Z+P+IA 3. 1 13-20 58.8(100%=134) TR-337 Z-6020/Glycidyl methacrylate/PETA/ITA(4:3:6: 12.8 P+Z+IA+GM 3 13.6 61 (100%= 142) M TR-338 Z-6020/Glycidyl methacrylate/ PETA/ITA(4:4:6: 12.8 GM+Z+P+IA NM 11.2 35 TR-339 Z-6020/Glycidyl methacrylate/PETA/ITA(4:4:6: 12.8 P+Z+IA+GM 3.4 9.8 40 TR-301 Z-6020/Glycidol/PETA/ITA(4: 1 10.4) G+Z+P+IA NM 0.2 NM TR-302 Z-6020/Glycidol/PETA/ITA(4: 1 10.4) P+Z+G+IA 4.4 0.15 1 12 TR-303 Z-6020/Glycidol/PETA/ITA(4: 1 10.4) P+Z+IA+G 3.4 0.25 66 TR-304 Z-6020/Glycidol/PETA/ITA(4: 1 10.4) G+Z+IA+P 2.7 8.0 123 TR-334 Z-6020/Glycidol/PETA/ITA(4:2 10.4) P+Z+IA+G 3.2 0.1 27.9 TR-335 Z-6020/Glycidol/PETA/ITA(4:4 10.4) P+Z+IA+G NM 0.25 22.6 TR-319 Z-6020/Glycidol/PETA/ITA(4: 1 12.8) G+Z+P+IA 3.7 12.5 37 TR-320 Z-6020/Glycidol/PETA/ITA(4: 1 12.8) P+Z+IA+G NM >500 NM TR-313 Z-6020/Glycidol/PETA/ITA(4:2 12.8) G+Z+P+IA 2.9 250 80 TR-315 Z-6020/Glycidol/PETA/ITA(4:2 12.8) P+Z+IA+G 2.6 12.3 36 Sample # Composition Addition Coat weight OTR 0% OTR 80% RH order (R/ 3 ) RH TR-341 Z-6020/Glycidol/PETA/ITA(4:3:6: 12.8) 25% solids P+Z+IA+G 2.9 10.7 48 TR-343 Z-6020/Glycidol/PE_TA/ITA(4:3:6: 12.8) 25% solids P+Z+IA+G NM 13.1 49 Other epoxies TR-317 Z-6020/EthGlyDiGlEther/PETA/ITA(4:0.25: 1 : 10.4) Z+P+IA+E NM >500 NM TR-318 Z-6020/EthGlyDiGlEther/PETA/ITA(4:0.25: 1: 10.4) Z+P+E+IA 1.4 2 176 TR-355 Z-6020/Bisphenol A/PETA/ITA(4:2: 1: 10.4) P+Z+GM+IA 2.3 6.7 35 TR-356 Z-6020/Bisphenol A/PETA/ITA(4:2: 1: 10.4) P+Z+IA+GM 3.1 0.15 77 TR-357 Z-6020/Bisphenol A/PETA/ITA(4:4: 1: 10.4) Z+IA+GM+P NM 0.3 179 Table 4 Sample Composition Primer OTR 0% RH OTR 80% RH TR-325 Z-6020/PETA/ITA(l 1.5:3.2) 3% Z6020 in IPA/water 1.1 144 TR-325.1 Z-6020/PETA/ITA(l 1.5:3.2) 1% Z6020 in IPA/water 1.3 111 TR-325.2 Z-6020/PETA/ITA(l 1.5:3.2) 0.1% 6020 in IPA/water 10.5 80 TR-326.2 Z-6020/PETA/ITA(4 1: 10.4) 0.1% 6020 in IPA/water 0.3 50 TR-327 Z-6020/PETA/ITA(l 1.5:3.2) 0.1% Peimine primer in IPA 10.6 76 TR-328 Z-6020/PETA/ITA(4 1: 10.4) 0.1% Peimine primer in IPA 0.15 31 TR-352 Z-6020/PETA/ITA(4 1 : 10.4) 0.1% Peimine primer in IPA 0.4 22 TR-352.1 Z-6020/PETA/ITA(4 1: 10.4) 0.01% Peimine primer in IPA 0.2 31 TR-353 Z-6020/PETA/ITA(4 1 : 10.4) 0.1% 6020 hydrolyzed overnight in 0.2 20 I A TR-354 Z-6020/PETA/ITA(4: 1 : 10.4) 12629/ 144-3 hydrolyzed l /2h in 0.1 20 IPA/water All solutions were prepared at 15% solids, except TR-352, 352.1 , 353, and 354 were prepared at 25% solids. EB conditions: 170 KeV, 10 Mrads. Table 5 Sample Composition Wetting agent OTR 0% OTR 80% RH RH TR-329 Z-6020/PETA/ITA(l 1.5:3.2) 1% polyethoxylated phenol 22.5 78 TR-329.1 Z-6020/PETA/ITA(l 1.5:3.2) 0. 1% polyethoxylated phenol 16.5 69 TR-330 Z-6020/PETA/ITA(4 1: 10.4) 1% polyethoxylated phenol 0.95 60 TR-330.1 Z-6020/PETA/ITA(4 1 : 10.4) 0.1% polyethoxylated phenol 0.25 28 TR-344 Z-6020/PETA/ITA(4 1: 10.4) 1% polyethoxylated phenol 0.3 88 TR-344.1 Z-6020/PETA/ITA(4 1: 10.4) 0.1% polyethoxylated phenol 0.4 68 TR-345 Z-6020/PETA/lTA(l 1.5:3.2) 1% polyethoxylated phenol 23.5 74 TR-345.1 Z-6020/PETA/ITA(l 1.5:3.2) 0. 1 % polyethoxylated phenol 17 69 b All solutions were prepared at 15% sold weight in IPA. EB conditions: 170 KeV, 10 Mrads. Table 6 Sample Composition Coat weight OTR 0% RH OTR 80% RH TR-346 STD 1: 1.5 on double side OPP primed with 0.1% carbodiimide, 15% NM 23.5 75 solids TR-347 STD 4: 1 on double side OPP primed with 0.1% carbodiimide, 15% 2.0 0.1 1 34 solids TR-347.1 STD 1: 1.5 on double side OPP primed with 0.1% carbodiimide, 25% 3.5 0.09 22 solids TR-351 STD 4: 1 on double side OPP primed with 0.1% unhydrolyzed Z-6020, 2.8 7.6 37 25% solids TR-369 STD 4: 1 on 0.1% PEI primed OPP with 0.1% polyethoxylated phenol, 2.9 0.65 23 25% solids b TR-369.1 STD 4: 1 on 0.1% PEI primed OPP with 0.1% polyethoxylated phenol, 2.9 0.4 23 top coated with 0.1% carbodiimide, 25% solids TR-370 STD 1: 1.5 on 0.1% PEI primed OPP with 0.1% polyethoxylated 3.15 7.3 38 phenol, 25% solids EB conditions: 170 KeV, 10 Mrads. PEI=polyethylenimine. Table 7 Sample Composition Wetting agent Addition order cw OTR 0% OTR R/ra 2 RH 80% RH TOR-360 Z-6020/GM/PETA/ITA(4:5 10.4) 15% solids Z+P+GM+IA 1.6 1.0 1 10 TR-361 Z-6020/GM/PETA/ITA(4:5 10.4) 5% solids Z+P+GM+IA 0.6 10.5 277 TR-359 Z-6020/GM/PETA/ITA(4:5 10.4) 25% solids 0.1% Polyethoxylated phenol Z+P+GM+IA 2.7 0.18 24 TR-365 Z-6020/GM/PETA/ITA(4:5 10.4) 25% solids 0.1% PEI primer Z+P+GM+IA 0.6 0.32 34 TR-366 Z-6020/GM/PETA/ITA(4:5 10.4) 25% solids 0.1% Polyethoxylated phenol on 0.1% Z+P+GM+IA 2.6 0.21 29 PEI primed film TR-363 Z-6020/GM/PETA/ITA(4:4:6:12.8) 25% solids 0.1% Polyethoxylated phenol GM+Z+P+IA NM 14.2 41 TR-363.1 Z-6020/GM/PETA/ITA(4:4:6: 12.8) 25% solids 0.1% PEI primer GM+Z+P+IA 3.1 12.5 42 TR-363.2 Z-6020/GM/PETA/ITA(4:4:6: 12.8) 25% solids 0.1% Polyethoxylated phenol on 0.1% GM+Z+P+IA NM 10.2 46 , Lπ» PEI primed film TR-358 Z-6020/Glycidol/PETA/ITA(4:2:6: 12.8), 25% 0.1% Polyethoxylated phenol P+Z+IA+G 2.6 0.15 34 solids TR-362.1 Z-6020/Glycidol/PETA/ITA (4:2:6: 12.8), 25% 0.1% PEI primer P+Z+IA+G NM 9.4 34 solids TR-362.2 Z-6020/Glycidol/PETA/ITA (4:2:6: 12.8), 25% 0.1% Polyethoxylated phenol on P+Z+IA+G 3.1 8.6 45 solids 0.1% PEI primed film TR-362 Z-6020/Glycidol/PETA/ITA (4:4: 1 : 10.4), 25% 0.1% Polyethoxylated phenol P+Z+IA+G NM 13.2 55 solids TR-364 Z-6020/Glycidol/PETA/ITA (4:4: 1 : 10.4), 25% 0.1% PEI primer P+Z+IA+G 3.0 0.1 34 solids Sample Composition Wetting agent Addition order CW OTR 0% OTR g/m 2 RH 80% RH TR-367 Z-6020/Glycidol/PETA/ITA (4:4: 1: 10.4), 25% 0.1% Polyethoxylated phenol on 0.1% P+Z+IA+G 2.9 24 solids PEI primed film TR-368 Z-6020/Glycidol/PETA (4:4: 1), 16% solids P+Z+G 1.4 >500 121 1 EB conditions: 170 KeV, 10 Mrads. *P=PETA, IA or ITA =ITACONIC ACID, Z=Z-6020, GM=GLYCIDYL METHACRYLATE, G=GLYCIDOL, E=EPOXY and PEI= POLYETHYLENIMINE. The letters are written in the order of addition of the components in the solutions. NM means "not measured". b Expenment 28 This compaπson example shows the barπer values of a coating including colloidal silica. A mixture of 1.08 g of aπiinopropyltrirnethoxysilane, 25.36 g of isopropyl alcohol, 1.36 g of hexanedioldiacrylate and 3.79 g of tnmethoxypropanetnacrylate was stiπed at room temperature for 72 hours. To this mixture was added 0.23 g of acrylic acid. The mixture was then allowed to stand for five minutes. Next, 12.73 g of Nalco 1129 (colloidal silica) was added while the mixture underwent vigorous agitation. The resulting mixture was then filtered through a 5 micron filter. All samples were applied on corona treated 50mu OPP, coated to a thickness of approximately 5mu with a #4 Myers rod. The samples were UV cured usmg a Fusion h bulb (360-365nm), 300W/ιn power rating, delivering a dose of between 300 and 500 mJoules. The wet barπer values are shown in Table 8 below. The samples showed extremely high oxygen transmission rates. Table 8 Sample Corona treatment OTR 80% RH Average 1AHS High 468 526 2AHS high 585 1ALS low 631 690 2ALS low 750 Expenment 29 PETA and Z-6020 were first reacted for an hour m the each of the respective solvents listed in Table 10, according to the standard 4: 1 ratio. Itaconic acid was then added. The coating was coated as 30% solids. Drying was performed m a moist oven, at 90°C and for 10 minutes. The coating was then EB cured at 170kV and lOMrads. The data vaπations were not large. The specific results are set forth in Table 10 below. Table 10 Formulation Solvent CW (ε/m 2 ) 0%RH OTR 80%RH OTR (cc/m 2 dav) (cc/m 2 dav) Z-6020/ PETA/ ITA (4 1: 10.4) Methanol NM 71 350 Z-6020/ PETA/ ITA (4 1: 10.4) Ethanol NM 42 185 Z-6020/ PETA/ ITA (4 1: 10.4) 1-Propanol NM 1.5 154 Z-6020/ PETA/ ITA (4 1: 10.4) 1-Butanol NM 1.1 214 Z-6020/ PETA/ ITA (4 1: 10.4) Dowanol PM NM 17 190 Experiment 30 Table 11 below illustrates that the coatings of the present invention can provide reduced oxygen transmission rates for a variety of substrates, such as low density polyethylene (LDPE) and polyethylene terephthalate (PET). In the 4: 1 formulation, a solution of 9.234g of SR295 (PETA Sartomer) was prepared in 120g Dowanol PM, and 23.296g of Z6020 was added. The solution was allowed to stand for 24 hours, then 35.468g of itaconic acid and 20g Dowanol PM was added and stirred. After coating and drying, the samples were exposed to electron beam iπadiation. For the 1: 1.5 formulation, a solution of 30.79g of SR295 (PETA Sartomer) was prepared in 112g Dowanol PM, and 12.948g of Z6020 was added. The solution was allowed to stand for 1 hour at ambient temperature, then 24.262g of itaconic acid and 28g Dowanol PM was added and stiπed to dissolve. After coating and drying, the samples were exposed to electron beam iπadiation. For the 4: 1/ 1: 1.5 blend, both solutions were prepared as described above, then mixed 1: 1, coated, dried and electron beam iπadiated. Table 11 Substrate Formulation OTR 0% OTR 100% LDPE (125mu) 4: 1 0.65 240 LDPE ( 125mu) 1: 1.5 ■ 17.5 134 LDPE (125mu) 4: 1 + 1: 1.5 0.5 43 LDPE (125mu) None 3000 3000 PET (50mu) 4: 1 0.25 19.5 PE (50mu) 1: 1.5 6.8 14.8 PET (50mu) None NM 21.4 Experiment 31 The following experiments illustrate that the order of addition of the aminosilane, ethylenically unsaturated acid and multifunctional acrylate components are not critical. "Semi-Quenched" 4: 1 5.432g of PETA was dissolved in 60g of dry isopropanol and 3.426g of Z-6020 was added. This solution was maintained for 30 minutes at ambient temperature then 20.864g of itaconic acid was added and while stirring 10.278g of Z-6020 was added. Stirring was continued until a clear solution was obtained. 3.5 g/m 2 was coated on OPP to give 9. Ice at 0%RH and 27cc at 80%RH. The film was initially primed with 0.1% polyetiiylenimine. This experiment was repeated maintaining all conditions the same, but without the primer and gave 0.3cc at 0%RH and 18cc at 80% RH. "Quenched" 4: 1 5.432g of PETA was dissolved in 60g of dry isopropanol and 20.864g of itaconic acid was added. While stirring, 13.704g of Z-6020 was added and stirring was continued until a clear solution was obtamed. 2.9g/m 2 was coated on OPP to give lcc at 0%RH and 15cc at 80%RH. "Quenched" 1: 1.5 A solution of 30.79g of SR295 (PETA Sartomer) was prepared in 112g Dowanol PM, 24.262g of itaconic acid and 28g Dowanol PM was added and stiπed to dissolve and finally 12.948g of Z6020 was added. The solution was coated and dπed, and the samples were subjected to electron beam lπadiation. 2.7 g/m 2 was coated on OPP to give 126cc at 0%RH and 157cc at 80%RH. Expenment 32 A solution of 9.234g of SR295 (PETA Sartomer) was prepared m 120g Dowanol PM, and 23.296g of Z6020 was added (4: 1 formulation). The solution was allowed to stand for 24 hours, then 35.468g of itaconic acid and 20g Dowanol PM was added and stined. After coating and drymg, the samples were exposed to electron beam irradiation. A second solution was prepared with lOg of polyethylenimine, having a molecular weight of 700M with 29 71g of itaconic acid, and 92.66g of IPA. This second solution was added to the first to arπve at a solution with solids ratios (1st formulation to second formulation) of 40.60, 60.40 and 80:20. Coat weights were in the order of 3.5 g/m 2 Barners at 80%RH were 60 9cc, 55. lcc and 80.7cc respectively. The foregoing specification desenbes only the prefeπed embodiment and the alternate embodiments of the invention. Other embodiments may be articulated as well. It is expected that others will perceive differences which while diffeπng from the foregoing, do not depart from the spint and scope of the mvention herem descnbed and claimed.

Claims: We claim: 1. Composition comprising: the reaction product, optionally dissolved in a solvent, of an aminofunctional silane having at least one molecule of the formula wherein 0 < a 4 R 1 is independently hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl, acryl, methacryl, alkylaryl, R 2 - SiR m (OR)3-m, or an alkylene linking group having 2 to 12 carbon atoms connected to one or two nitrogen atoms, with the proviso that at least one R 1 is a hydrogen atom and at least one R 1 is an R 2 - SiR m (OR) 3 -m group, where m is 0, 1 or 2, and R is independently a hydrogen or an alkyl group having from 1 to 6 carbon atoms; R 2 is independently selected from the group consisting of: linear or branched alkylene groups having from 1 to 12 carbon atoms; arylene groups having from 6 to 12 carbon atoms; and linear or branched hydrocarbon groups having from 1 to 16 carbon atoms and at least one alcohol, alcohol ether, ester, amide, urea, thiourea or polyether group; a multifunctional acrylate having a molecular weight of from 100 to 3000; and an ethylenically unsaturated acid. 2. Composition according to claim 1, characterized in that the aminofunctional silane is N-(2- aminoethyl)-3-aminopropyltrimethoxysilane or aminopropyltriethoxy silane or blends thereof. 3. Composition according to claims 1 or 2, characterized in that the composition has a total amine functionality and a total acrylate functionality and the ratio of amine functionality of the aminosilane to the acrylate functionality of the multifunctional acrylate is from 4: 1 to 1: 1. 4. Composition according to claim 3, characterized in that the composition has a total amine functionality and a total acrylate functionality and the ratio of amine functionality of the aminosilane to the acrylate functionality of the multifunctional acrylate is about 2: 1. 5. Composition according to claims 1 or 2, characterized in that the composition has a total amine functionεdity and a total acrylate functionεdity and the ratio of amine functionality of the aminosilane to the acrylate functionality of the multifunctional acrylate is from 1: 1 to 1:6. 6. Composition according to claim 5, characterized in that the composition has a total amine functionality and a total acrylate functionality and the ratio of amine functionality of the aminosilane to the acrylate functionality of the multifunctionεil acrylate is about 1:3. 7. Composition according to anyone of claims 1 to 6, characterized in that the multifunctional acrylate is selected from the group consisting of: acrylated polyols with molecular weights from 150 to 600; polyester acrylates with molecular weights from 1000 to 2000; polyether acrylates with molecular weights from 200 to 1500; polyester urethane acrylates with molecular weights from 400 to 2000; polyurea acrylates with molecular weights from 400 to 2000; epoxy acrylates with molecular weights from 300 to 1000; and mixtures of multifunctional acrylates. 8. Composition according to claim 7, characterized in that the multifunctional acrylate is selected from the group consisting of: pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, trimethylolpropane triacrylate, glycerol triacrylate, triacrylate ester of tris-[2- hydroxy-ethyl] isocyanurate, hexanediol diacrylate, and dipentaerythritol hexacrylate, and ethoxylated and propoxylated derivatives of the above. 9. Composition according to anyone of claims 1 to 8, characterized in that the reaction product is dissolved in a solvent and the solvent is a water/ alcohol mixture where the alcohol present in an amount of 1-99% and the solvent constitutes 60-95 parts by weight of the total composition. 10. Composition according to anyone of claims 1 to 9, characterized in that the molar ratio of the ethylenically unsaturated acid to the aminofunctional groups of the silane is from 1: 1 or greater. 11. Composition according to anyone of claims 1 to 10, characterized in that the ethylenically unsaturated acid is selected from the group consisting of itaconic acid, fumaric acid, maleic acid, citraconic acid, methacrylic acid, acrylic acid, sorbic acid, cinnamic acid, vinyl sulfonic acid, mesaconic acid and itaconic acid monomethylester, and mixtures thereof.. 12. Composition according to anyone of claimsl to 10, characterized in that the ethylenically unsaturated acid is a dicarboxylic acid or a monoalkylester thereof. 13. Composition according to anyone of claimsl to 12, characterized in that the aminofunctional silane is N-(2-aininoet_iyl)-3-aminopropyltrirnethoxysilane or aminopropyltriethoxy silane, the ethylenically unsaturated acid is itaconic acid, and the multifunctionεd acrylate is pentaerythritol tetraacrylate. 14. Composition according to anyone of claimsl to 13, characterized in that the molar ratio of aminofunctional silane to multifunctional acrylate is about 1: 1.5. 15. Composition according to anyone of claimsl to 14, characterized in that said composition includes an additive. 16. Composition according to claim 15, characterized in that said composition includes an additive, and said additive is selected from the group consisting of a silane, polyethylenimine, glycidyl methacrylate, glycidol, ethylene glycol diglycol ether, bisphenol A, polyethoxylated phenol. 17. Composition according to anyone of claimsl to 16, characterized in that said composition is coated on a substrate. 18. Method comprising the steps of: (I) coating a composition according to anyone of claims 1 to 16 on a substrate (II) exposing the coated substrate of (I) to moisture, and (III) treating the substrate of (II) to initiate a free radical reaction. 19. Method according to claim 18, characterized in that the free radical reaction of step (III) is initiated by electron beam radiation, gamma radiation or ultraviolet radiation, optionally in the presence of photoinitiators, or said free radical reaction is initiated thermally in the presence of a free radical generator. 20. Method according to claim 19, characterized in that the electron beam radiation has an energy of from 50 KeV to 10 MeV and greater than 2.5 Mrads. 21. Method according to claim 20, characterized in that said composition is cured by electron beam radiation at 150 KeV and at least 5 Mrads. 22. Method according to anyone of claims 18 to 21, characterized in that step (II) comprises heating the coated substrate of step (I) in the presence of moisture. 23. Method according to anyone of claims 18 to 22, characterized in that the substrate is selected from the group consisting of polyolefins, including oriented polypropylene (OPP), cast polypropylene, polyethylene and polyethylene copolymer; polystyrene; polyesters, including polyethylene terephthalate (PET), or polyethylene naphthalate (PEN); polyolefin copolymers, including ethylene vinyl acetate, ethylene acrylic acid and ethylene vinyl alcohol (EVOH), polyvinylalcohol and copolymers thereof; polyamides, including nylon, and MXD6; polyimides; polyacrylonitrile; polyvinylchloride; polyvinyl dichloride; polyvinylidene chloride; polyacrylates; ionomers; polysaccharides, including regenerated cellulose; silicone, including rubbers or sealants; natural or synthetic rubbers; glassine or clay coated paper; paper board; craft paper; and metallized films and vapor deposited metal oxide coated polymer films, including A10 x , SiO x , or TiO x . 24. Method according to anyone of claims 18 to 23, characterized in that the substrate is treated with a primer. 25. Method according to claim 24, characterized in that the primer is selected from the group consisting of a silane, polyethylenimine, and carbodiimide. 26. Method according to anyone of claims 18 to 25, characterized in that the substrate of step (III) is disposed on one or more additional substrates to form a laminate, and said additional substrate or substrates are optionally primed. 27. Method according to claim 26, characterized in that the additional substrates used to form the laminate are selected from the group consisting of polyolefins, including oriented polypropylene (OPP), cast polypropylene, polyethylene and polyethylene copolymer; polystyrene; polyesters, including polyethylene terephthalate (PET), or polyethylene naphthalate (PEN); polyolefin copolymers, including ethylene vinyl acetate, ethylene acrylic acid and ethylene vinyl alcohol (EVOH), polyvinylalcohol and copolymers thereof; polyamides, including nylon, and MXD6; polyimides; polyacrylonitrile; polyvinylchloride; polyvinyl dichloride; polyvinylidene chloride; polyacrylates; ionomers; polysaccharides, including regenerated cellulose; silicone, including rubbers or sealants; natural or synthetic rubbers; glassine or clay coated paper; paper board; craft paper; and metallized films and vapor deposited metal oxide coated polymer films, including A10 x , SiO x , or TiO x . 28. Packaging container comprising at least one silicone containing layer forming an integral part of said packaging container, characterized in that said silicone containing layer is formed by a method according to anyone of claims 18 to 27. 29. Packaging container according to claim 28, characterized in that the package is selected from the group consisting of a pouch, tube, viεd, bottle, bag-in-box, stand-up pouch, gable top carton, thermoformed tray, brick-pack, box, and cigarette pack.

Inventors: BRANCH KAREN, FUTTER DAN, MERLIN PATRICK J, POWER GARY, RANGWALLA IMTIAZ, WYMAN JOHN E, BRANCH, KAREN, FUTTER, DAN, MERLIN, PATRICK, J., POWER, GARY, RANGWALLA, IMTIAZ, WYMAN, JOHN, E.
Applicants: BRANCH KAREN, DOW CORNING, EG TECHNOLOGY PARTNERS LP, FUTTER DAN, MERLIN PATRICK J, POWER GARY, RANGWALLA IMTIAZ, UCB FILMS PLC, WYMAN JOHN E, BRANCH, KAREN, DOW CORNING CORPORATION, EG TECHNOLOGY PARTNERS, LP, FUTTER, DAN, MERLIN, PATRICK, J., POWER, GARY, RANGWALLA, IMTIAZ, WYMAN, JOHN, E.
Application year: 1998
Main classification: C08F230
IPC codes: B65D65, C08F290, C08L79, C09D4