CA2278150C - Silicone/multifunctional acrylate barrier coatings - Google Patents

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

..... .=,,.,-nt.a~tttt,.~ ./~ :1-J~ St . UU31'23773516-= +49 89 2;t984465410 30.39.WO sl1=icoliZlmMTWvaoTtOXw4,.ACRYLATV BARRMR COA'1'I1QO3.

Mid of tha Inyeatim The invention relates to silicone coatahting compoeitim and coatings formed therewith haviAg barrier properties which are useRil in pw-lag-ng aPpbc++dm. In another aspects, the invention relates to a method for the manufacture of a coated substrate having barrier properties and to a packtging container.
BUkroua of the Iaventioa It is well known that coatings coritaining silane compounds and itaconic acid improve the gas, oil, and flAvor bacrier performance of organic polymer film substrates.
Moreover, the adhesion of the coating to the film surface, as well as the improved bariier characteristics provided by the silane coating, are greatly enhanced by exposing the coated Slm to electron beam radiation.
A partlcularrly useflzl barrier composition is described in IJ,S. Patent No.
5,215,822, which teaches a methancl solution of n vinyl benzyl amine silane (Dow Corning Corp.
Z-6032), itaconic acid, and water, coating this solution on a corona truted low density polyethylene film, drying, and then subjecting the coated film to electron beam radiation to graft the coating to the Slm aurface and further improve the barrier properties of the silane coating.
However, while this coating gives exceller:t gas barrier properties at low to moderate relative humidity values, the gas .
permeabiliRy increases drastically at very high relative humidity values.
The present inventors have surprisingly discovered that the combir.ation of an aaiinofunctional silane, a mult:ftinctional acrylate and an ethylenicaUy unsatumted acid gms excellent gaw barrier properties at low to moderate relative humidity values, as well as excellent gas barrier properties at very high relative humidity values, While other patents teach the combination of a mono or multifiuictional acrylate with an aminolttnctional 's~:ane, none teaches the addition of the etVenically unsaturated acid with an acrylate. For example, U.S. Patent No. 5,368,941 teacties a deformable, abrasion-resistant coating formulated froaa at 1east one multi=fuactional acrylate monomer, at least one auninott~nctiouai silane, colloidal aiHca end at least one aaylate-terminated po~,valkylene oadde.
The acrylata-terminated polyalkylene mdde helps prevent gelling of the coating composition duruig stripping and aleo imparts tlu composition with deformability, without sacrificing abrasion te9istsnce.
Also, U.S. Patent No. 3,434,007 teaches a silane reain coated on a ptaltic fllm, where the silane resin is composed of a monoiLi ctional acrylate and an aminofianctunal eilaae.
The oomposit,ion does not utilize a tree radical cure, nor does it incorporate the ethylenioally unsaturated acid.
U.S. Patent Nos. 5,260,350 and 5,374,483 and EP-A-666,290 relate to a silicone coating composition which, when cured or, a solid substrate either by ultraviolet or electron beam radiation, provides a tsanapubnt abrasion resiswt coating firmly adhorod thereon. The silicone coaNng is prepareQ by reacting at least one multilhnctlonai aaylate monomer with aa am4no-orgav:ioflunctiorAl silarLe, mndng the modifled silane with at least one acryllc monomer and thereaftor adding colloidal ailica. Again however, neither of these compositiona teach the addition of an ethylenically unsaturated acid to achieve barrier propexties.

n~, .~n~ = ci'n .~I~t:,~l HL:~ U4 i !-y~i = 1:' J! . UUZ311:3775516-. +4U 89 2 (Kokai) publication 7.18221 publiehed on January 20, 1995 teaches a aurface treatment composition for Su barrier comprising an aminosilane and a compound having an aromatic ring or hydrogenated ring. The present invention is d'utinguishable, however, because it does not require the addition of cyclic cornpotwda having an aromadc ring.

3 The present invention ia distinguishable over each of the above cited prlor art because none teach the combination of an aminosilane, multifunctional acry]ate and ethyknically unsaturated acid to achieve gss barrier propernea.

8.nmmarf af the tnrention The invention is a composition made by mixing in any order a multiflinctional acrylate with an amino Ausctional silane and an ethylenicaIly unaaturated aoid to ~om a reaction product, optionally dissolved in a solvent, wherein the multifunctional acrylate hae a molecular weight of from about 100 to about 3000, and the unlaoiunctional silane has at least one molecule of the formula R3--~N Ra -N Rl ~i Rl wherein 0<A:S 4 R, is indopendently hpdrogen, alkyl, subetituted akv1, aryl, substituted aryl, arylallcyl, acryl, methactyl, a1Wlaryl, RI - Si&(OR)3-m, or an alkylene linking group having 2 to 12 carbon atoms connected to one or two nitrogen atoms, with the protriso that at least one Rl is a hydrogeo atom and at least one RI is an Silt,(OR~.m group, where a is 0, 1 or 2, and R is independently a hydrogeu or an alkyl group having from 1 to 6 carbon atoms;
R2 is independenaly selected from the group c.onaisting of lirrear or branched aklene groups having from I to 12 carbon atoms;
aryleae gnroupe having from 6 to 12 carbon abome; and tit-eaur or brancb,ed hydrocarbon groups having from I to 16 carbon atoms aad at leaet one alcohol, alcohol ether, eater, amide, urea, thiourea or polyether group.
In the scope of the preeeunt description, molecular wefght mceae number average molecular weight in the caae of polymers and mct waight in the ease of small moleculee or of oligomers.
The composition can be coated on a substrate, then optionally exposed to moisture and treated to initiate afte radical reaction. The composition cau be applied to a variety of subetrates used in packaging applications. The compoadtion can be cured by further heating in the presence of moisture, The free radical reaction can be laitiated not onlq by hatiag but by electron beam irradiation, ultraviotet radiation, gamma radiation, and/or heat and chemical free radical Initiators.

WD 9017m PCT/BE98l00006 A composition according to the present invention may be employed to provide a barrier layer which improves resistance of the material to transmission of gases and aromas therethrough.
For eaiample, a 30 micron uncoated biaAally oriented, corona treated polypropylene film is genenally found to have a permeability to oxygen of 1500 cc/m2/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/m2/day as measured at 80% relative humidity. As used herein, the tenninology "improved barrier"
refers to a coating which can reduce oxygen transmission rate of the aforementioned uncoated polypropylene film from 1500 cc/m2/day to 250 cc/m2/day as measured at ASTM D3985-81 measured at 80%
relative humidity.

Descrivtioa of the Preferred Embodiments While the invention is susceptible of embodiment in many different forms there is described herein in detail preferred and alternate embodiments of the invention. It should be understood, however, that the present disclosure is to be considered an exemplification of the principles of the invention and is not intended to limit the spirit and scope of the invention and/or claims of the embodiments illustrated.

Aminofuactional Silanes The aminofunctional silanes are described generally by the formula:
R1 - N Rj - N 4 RI
kAija wherein 0<a<4 RI is independently hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl, acryl, methacryl, alkylaryl, R2 - SiRm(OR)3.m, or an alkylene linldng group having 2 to 12 carbon atoms connected to one or two nitrogen atoms, with the proviso that at least one Ri is a hydrogen atom and at least one Rl is an SiRm(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;
R2 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 invention are N-(2-WO 98l31710 PCT/BE98f00006 aminoethyi)-3-aminopropyltrimethoxy silaae, and aminopropyltruthoxysilane, and blends thereof.
For the purposes of the present invention, the above mentioned amine functional silane group has the general formula Rl-N R~--N 4 Rl ~1 klJa In the above formula, RI is a monovalent radical independently 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-trifluoropropyl;
aryl having 6 to 16 carbon atoms, such as phenyl and naphthyl; substituted aryl having 6 to 30 carbon atoms, such as chlorophenyl, chlorotolvl and dichloroxylyl; arylalltyl having 7 to 9 carbon atoms, such as benzyl, phenethyl and 3-phenylpropyl; and aikylarvl having 7 to 16 carbon atoms, such as tolyl, xylyl, ethylphenyl and propyltolyl. According to the invention, at least one R' group is hydrogen. Further, at least one R' is an R2 - SiRm(OR)3.,o group, where R is an alkyl group having from 1 to 6 carbon atoms, m is 0, 1, or 2 and R2 is defined below. The remaining R' groups on the aminosilane are preferably hydrogen or methyl.
RI can also be an alkvlene linlting group which links two different nitrogen atoms on the same molecule together, thus forming a cyclic aminosilane. The alkvlene linldng group can also be an arylene group which is connected to two different bonding sites on the same nitrogen atom. The alkylene linldng group will have at least 2 carbon atoms and as many as 12 carbon atoms.
R2 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, R2 can be an alkylene group having at least 1 carbon atom or an arylene group having at least 6 carbon atoms.
Preferably, R2 is selected from the group consisting of ethylene, propylene, butylene, isobutylene, trimethylene, tetramethylene, and hexamethylene.
In addition, R2 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, arnide, urea, thiourea or .polyether group. Specific examples of such groups include, those having the general formula -CH2CH(OH)(CH2)x-, -CH2CH(OH)(CH2)x -0-(CH2)Y- , -CHzCH(CHa)C(sO)-0-(CH2)y-, -CH2CH2C(=0)-0-(CH2)y-, -CH2CH2C(=O)-N(R)-(CH2)y-, -C(=0)-N(R)-(CH2)y-, -C(=S)-N(R)-(CH2)y-, or where x and y are each integers from 1 to 12. The hydroxyl and ester groups are highly polar, and it is believed the polar nature of the groups improve barrier properties.
Examples of specific amine-containing groups include such structures as -CH2CH2CHINH2, -CH2CH2CH2N(H)CH2CH2NH2, -CH7CH2CH2N(H)CH2CH2N(H)CH2CH2NH2, -CH2CH2CH2CH2NH2, -CHgCH2CH2CH2CH2NH2, -CH2CH2CH2N(H)Me, -CH2CH2CH2N(H)CH2CH2NMe2, -CH2CH2CH2N(H)Et, -CH2CH2CH2N(Et)H, -CH2CH(CH3)CH2N(H)CH2CH2NH2 and -CH2CH(CH3)CH2NH2, inter alia, wherein Me and Et denote methvl and ethvi, resnectively. :;
specific example of an amine containing cyciic group is pinerazine.
As used herein the term aminofunctional siiane' can mean a singie spectes of the for-nuia described above, such as N-(2-aminoethyl)-3-aminapropyltrimethoxy silane, or it can mean 5 mixtures or one or more species of atttinofunctional silanes, such as N-(2-aminoethyl)-3-aminopropyltrimethoxv silane and aminopropyltriethoxysilane.
The above described aminofunctionai silanes can be prepared by methods known co those sidlled in the art, and which are amply described in the chemical literature.

Multifuactioaal Acrylates The muitifunctional acrylates of the present invention are deiined as acrylates having, on average, greater than two functional acrviate groups per molecule and a molecular weight of from about 100 to about 3000. Multifunctional acrvlates are nreierrea over monofuncuonai acrylates because monofuncuonal acrylates do not form flexible, c-acic frec coatings as do the multifunctional acn=lates. The tnaiotity of multiiunctionai acrviates commercially available can be used, but it is the smaller, more compact, i.e., proportionally more reacuve acn=iates that give the best results. The multifuncuonal acr viates are preferably seiected from the group consisung of acn=lated polyois with molecular iveights of from about 150 to about 600: poivester urethane acrviates with molecular %veights of from about 1000 to about 2000:
poiyether acr<=iates ivith moiecular weights from 200 to 1500; poivurethane acr}=lates tvith moiecuiar weights of from about 400 to abouc 2000; polyurea acryiates tvith molecular :veig_~.ts of from about 400 to about 2000: epoxy acrvlates uuh molecular weights of from about 300 to about 1000; and mixtures of multifunctional acn=lates thereof.
Most preferred acrylates are pentaerythzitol tetraacrylate; an acid functional acr,vlace; polvester *
tetra acrylate; polvether tetra acrylate; an aliphauc urethane acrylate.
Ebecrvi 1290;
ditrimethylolpropane tetra acrylate; an ethoxylated trimethylol propane triacrylate, Ebecryl 160.
Other preferred acrylate include glycerol triacrylate, triacrylate ester of tris-[z-hydroxy-ethyl]
isocyanurate, hexane dioldiacrylate, and dipentaerythritol hexacrylate.
Ethoxylated and propoxylated versions of these acrylates may be used in this invention. These acrylates and methods of their production are well know in 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 acrviates 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 vinyl unsaturation. It is beiieved that the ethylenically unsaturated acid * Trade-mark substannally improves the oxygen barrmer neriormance of the comnosition because the carboxviic group forms an amine salt with amino groups of the aminosilane. wiiic:z conmbutes siguficant:v to the coatuig's barrier properaes. The ernylenically 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 bv weight being most nrefetzed. The most preferred ethylenicaily unsaturated acids used in the present invention are dicarboxyiie (i.e. have trnro carboxvlic acid groups) or monoallevlester thereof and the most preferred is itaconic acid: however, other acids such as fumaric, :naieic, citraconic, znethacr-vlic, acrylic, sorbic. cinnam:c, vinyl sulfonic acid, mesaconic acid, and itaconic acid monomethvlester may aiso be used. The term "ethvlenicailv unsaturated acid" as used 'nere:n includes mixmtres of one or more of the aforementioned acids.
Solvents The components of the present invention can optionallv be reacted togetner in a solvent. In general. water, alcohols and blends thereof will serve as suitable soivents because the tnultuunctional acr}=late and the ethyle:ucailv unsaturated acid are soluble therein. Typically.
the solvent is a waterjalcohol miYture where t-he alcohol is present in an amount of about 1-99%. In addition, the se:ected solvent must :vet rhe substrate. Preferably, the soivent will be nonto.xnc. and will not extend the dry-ing time ai the coating beyond what is commercially acceptable. The amount of solvent can range :r om about 20 to about 99 oarts bv weight and :s preferably from about 60 to about 95 parts by n=eight of the total composinon.
Preferred solvents are methanol, ethanol, n-propanol, isooropanoi. butanol, and 1-methoxy-2-propanol (available as ~
"Dowanol PVI" from the Dow Chemical Co., Midland, MI).
Critical Ratios Dur:ng the reaction of aminosilanes with tnultifunctional ac--ylates, it is possible to utilize an excess of multifuncnonal acrylate over and above that required to react with the amino nitrogen atoms. In multifunctionai acrylates, such as pentaerythritol tetraacrylate, the amine chains attached to the trimethoxvsiiyl groups may also have pendent acrylate groups which will undergo further polymerization under the iniluence of ionizing radiation. It is believed that the acrylate groups of the multifunctional acrylate and the amino groups of the aatinofunctional silane undergo an addition reaction (Michael Addition) readily upon tnixiag of these two components. In addition, hydroxyl groups and solvents present mav interact with alkoxy groups attached to the silicone atoms of the aminofunctional silane and cause a thickening of the composition at ceztain concentrations of the components in the solvent.
For example, one may employ an "amine rich" syst.em, 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 preferred, and with a * Trade-mark rv,Nrrn-AU:rNlNt\ 04 i- w-98 . 1::::38Ut,i ?77,5516- +ty 89 2843~3.44E;5:N1::

ratzo of 2:1 being most prederred. In the case where the aaninosunctional silane is N-(2=
amiaoethyl)=3-aminopropyltnmethoMy silasie or aminopropyltriethosysildne, and the znultiitlnctional acrylate is pentaerythritol tetraacrylnte, the ratios in the amine ricb system can be expreseed in terms of malar ratios, with the preferred molar ratio of aminosilane to muldfunetional acrylate beiag from about 6:1 to about 1:1, with a molar ratio of about 4:1 being most preferred.
Excellent results caa also be achievw..d using an "acaylate rich" syatem, where the total number of reactive nitrogen sites in the compoaition 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 multhnctional acrylate, i.e., the ratio of amine fltnctionality to acrylate functionality can be from about 1:1 to about 1:6, with a range of about 1:3 being preferred. In the case where the arainofunctional eiluse is N-(2=amirsoethyl)-3-aminopropyltrixaethoay sitane or aminopropyltriethoxysilane, and multifundiot3al acrylgte is pentaenthsttol utraacrylate, the ratios of the aerylate rich eystem can be expressed in terma of molar ratios, with the preferred mrolar ratio of aminosilane to multiituictional acrylate being from about 1:1 to about 1:3, with a molar ratio of about 1:1.5 being most preferred, The molar ratio of the ethylenically unsaturated acid to the aminofunctional silane is about 1:1 or greater.
Although the order of addition of the components to provide a compoeition according to the present invention is not cr.tieal, certain ir.ethods are praferable, For example, the arainofunotional silane and the acrylate component can be added together to form a Michael Adduct, before the addition of the etktJleaically uasaturated 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 unaaturated acid can occur at any point in the reeuction procesa, i.e., the acid may be added to the anninosilute before any acrylate is added, or after most of the actybtte ie added. Practically, the reacdon :aay be quenched at a predetermined point by simply adding part of the acrylate to the amirlosilane, then adding the reet of the acrylate and the aad to this mixture. It is preferred that the quenching technique be used with the amine rich 30. formulations of the invent:on, Coat Welght The eoating can be applied in any desired amount, however, it is prefenrod t'iat the coating be applied in an amount of from about 0.05 to about 20 gme/ml, the preferred coating weight being from about 0.5 to about 10 gmsW. Coating weight cain be determined by gravimetric eomparimon. The coating can be kpplied to the subetrate by any conventional method, such as spray coating, roll coating, slot coating, meniaeua coatictg, immerxion coating, and direct, offset, aad reverse gravure coating.
6Wbstxates The coating can be disposed on a wide variety of aubstlxtes, includiag, but not limited to CA 02278150 1999 - 07 - 15 AMENDED SMIIfi 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 metaIlized polymer films and vapor deposited metal oxide coated polymer films, such as AIOx, SiOx, or TiO,.
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, polvamides, 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 varietv of packaging containers, such as pouches, tubes, bottles, vials, bag-in-boxes, stand-up pouches, gable top cartons, thermo-formed travs, 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-aminoethyl)-3-aminopropyltritnethoxy silane and aminopropyltriethoxysilane.

While the compositions of the present invention wiIl 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 preferred and temperatures of about " =, 90 C to about 1 10 C being most preierrec. Heaung u.e s temperarare aepeneent and the coaung will reaca tack free tune :n one to 10 seconas. The heaung step serves to evaporate *..~e soivent :vhen used and acce!crate the cor.densauon reacuon benveen Si-OH
groups and SiOH/SiOH groups.
The compositions may be furtr:er cured by uvttaunq a free radical reactson.
The most pre_erred method oi ir.tuaung the free radicai reacuon is througi=t the use oi eiectron beart radiacon.
although uit.-avtoiet or free radicai generators sucin as azo compounds and peroxides may aiso be used.
The compositions are preierabiv cured bv a free radical generator, such as uit.-aviolet. eEec=on beam, or gamma radiauon or chemical free radical generators such as azo compounds ar.c peroxides. Low energy electron beatn irraciauon is the preferred method of cu:
Zg because :t :s cheaoer than garnraa sources iike Cobalt,*4-60. Its advantage over ultraviolet ra(iiauen as a cure scste: :ies u: its abilitn- to sene:ate free radicals without photoiniuators.
It also unpa.:s niener :ie:ds oi c:ossiinic denstty anc c: e.=rttcal graft:nt; of the coaung to the substrate. E'.ectro:: bear.t :5 acceierators oi var.ous :y-pes suc:: as van de Graaf-q-pe, resonance transformer-type, :u-.eaz-yFe.
(wnamatron-t}-ne anci t:igh ire-qsency-n=pe can be used as a source of electron beam. -_-'.ect:en beam having energ- oi :rom about 5 to about 2000 Iie :l. preierabiv irom about 30 to about 300 KeV discharged therefrom may be irradiated in a dose of from about 0.1 to about ! 0'.fracs 11viR).
Low eiecc:on beam voltages Iless than 20 i:eV) mav be used if the substrate is treatea ~ a vacuu:n. Commercially avatiable sources of electron beam are E!ectro Curtain C3-I50 avaiiabie from Energy Sciences. Inc. (l4ilmington, MA).
The compositions may also be :iltravioiet light cured if one or more phototniuators is addec oner to curing. There are no soeciai restrictions on the photoiniuators as long as they can generate radicals bv :he absorpaon of optical enero,. Ultraviolet light senstuve photomiuators or blends oi intuators used in Lhe UV cure of the present composition include 2-hydroxv-2-methvl-l-pnenvi-propan-l-one (Darocure*1173), sold by EM Chemicals, and 2,2 Dimethoxv-2-pnenyi-acetol-ohenone (Irgacure 651), sold by Ciba-Geigy Corporanon. Hawthome, New York. For purposes of this invenuon, it has been found that from about 0-05 to about 5 weight percent based on the total soiids in the composiuon, of the photoinitiators descnbed heretn will cause the composiuon to cure.
In addition to radical polymerization and grafting to crosslink the coatzrtg after it has been applied to the substrate. it is possible to further crosslink the composition utilizing acid catalyzed condensation reacuons. In this reaction, a methoxylated active hydrogen compound, such as trimethytol phenol, or a mixture of formaldchyde with aldehvdes, ketones, and other acuve hvdrogen compounds react with amine salts, such as the itaconate salts of the amine silanes or derivatives to form alkvlated amines.

Preferred Embodiments To prepare the preferred embodiment of the invention, the acrylate component, preferably * Trade-mark pentae-~-thntol tetraacrviate (PETa), is dissoived in a soivent such as Dowanol PM. The silane.
preierabiv N-(2-ammo ethyl) gamtna ammopropyi trimethoxvstiane is added to the acrvlate soiuuon so that the molar ratio of arninosiiane to acrviate is about 4:1. This mixture is allowed to equilibrate for one hour at ambient conditions. Itaconic acid. in an amount of about 1.3 moies 3 per gram atom of ni.trogen is then added to the equilibrated solution. The coating solution is applied to corona treated 30 micznn thick "I2AYOPP" oriented polvpropyiene film from UCB Films.
The coated film is placed immediately in an oven maintained at about 80-100 C
and heid there for about 10 minutes. The oven is maintained at a relative humiditv of about 50%.
The dried coated film is then "cured" bv an electron beam dose of 10 Mrads at 170 W.
Optional Additives Various opuonai additives can be added to the comnosition to improve various properues. These additives mav be added as desired and in anv amount as iong as thev do not reduce the periormance of the barrier coaungs as iilusuated herein. Exampies of additives include : S additional additives as eariier described, anublock and sliu aides such as stearamide. oleamide or polar additives, such as epoxides, poiyois. glycidois or polvamines, such as poh=eth}=ien.unine, and other silanes mav be added. Soecii:cailv excluded from the scope of the present invenuon are colloidal silicas and siianes or other rnoiecuies having four alkoa}= or other hvdroivzable groups disposed on a singie silicone or other organometallic atom, such as tetra etho:ty silane, and the like. Wetttng agents, such as a polyethoxylated allcvi nhenoi may also be added.
Examples E.epe:iments 1-10 illustrate the utilitv of a mixture of itaconic ac:d with the Michael addition product of various acrylate esters with N-(2-armno ethyl)gamma aminopropyl trimethoxysilane, = 25 hereinafter referred to as Z-6020, as a gas barrier coating on poiypropylene fiim In espenments 1-12 the Z-6020, acrylate ester, and itacotuc acid were utilized in a moiar ratio of 4:1:10.4 with a total solids content of 34 grams / 104 grams of solution. The solvent employed in all the e.+cperiments described below was 1-methoxy-2-propanol, available commercially from Dow Chemical Company (Midland, MI) as "Dowanol PM". The Z-6020 was obtained from Dow Corning Corporation (Midland. Ml) and the itaconic acid from Aldrich Chemical Company (Milwaukee, WI). The coating solutions were all applied to corona treated 30 micron thick "RAYOPP" oriented polypropylene film from UCB Films utilizing a # 12 Myers rod. The coated film was placed immediateiy 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" bv an electron beam dose of 10 Mrads at 170 KeV.
The oxygen permeability values for each filsa were measure and recorded in units of cc/ square meter per 24 hours, "dty" vaiues being 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 * Trade-mark V1H. The N1OCON insttvments wet e obtauted from Modern Controls Corporation.
For companson, the poiypropy iene base film had a pertueability of about 1500cc;
souarer meter 24 hours.

E.,m r=nent 1 :1 soiution oi 3.777 g. of "rbecrvl 770", a raonofuncuonal polyester acryiate with a rcportea :noiecuiar =.vetght oi 280. obtaLned from UC3 Radcure, in 70 g, oi Dowanol PM
was areparea at a 1.982 g. oi Z 6020 was added with stimng. After one hour at amb:ent te:nxrature. 18.241 g.
oi itaconic acid was added and stuzed to dissolve. While measuring the dr=
pe.~.neao-ilin=, the i0 sump:e deveioped numerous cracKs, w'r=.ich made the coating unsuitable for use as a barner r' :..
EYpe.~.sne.~.,. '.'.
A soiuuon of 9.74- g. oi "LbecnIi 810", polvester tetra acrylate with a re-~ortea moiecuiar We:;nt of 900 obtained from i;C9 Radcurc, was prepared in 70 g. oi Dowanol PM. and 9.615 g. of ~
~ 5020 was added. After stand:ng at ambient temperature for one hour, 14.641 g. of iraconic ac:d was added ana stt.-Tec to dissoive. After coaung, drying and curing the dry ;:errneabiiity was :23cc and the wet oe.~aeabilin= was 259cc.

Exoe.n.ment 3 3!~ - soiuuon of 3,782 ;. oi "Ebecnti=l 1290'. an aliphauc urethane acn=iate having six acn=iate grouns per :nolecule =xnh a reported molecuiar :veisht of'80, obtained from L'CB Radcure, was orcpared in 70 g. of Dowa.~oi i'!14. and 9.996 g. of Z-6020 was added with sttrn.-tg. After standing at ar::bient temperature for one hour, 15.222 g. of itaconic acid tivas added and surred to dissoive. After coating, d~-ing and cunng, the permeability was 5.23cc drv and 38cc wet.
Experiment 4 A soluuon of 5.885 g. oi "Ebecyl 140", ditrunethylolpropane tetra acrylate, reported molecuiar weight 466, obtained from UCB Radcure, was prepared in 70 g. of Dowanol PM. To this soluuon was added 11.159 g. of Z-6020 and after standing one hour at ambtent temperature, 18.285 g. of itaconic ac:d was added and stirred to dissolve. In this experiment, 11.2 moles af itacoruc acid was employed and the solids were 35.299 g. in 105.299 g. oi solution. After coating, drying and cunng, the permeability was 1.1ec dry and 151cc wet.

Expenment 5 A solution of 5.454 g. of "Ebecryl 160". an ethoxylated trimethylol propane triacrylate 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 standing one hour at ambient temperature, 17.231 g. of itaconic acid was added and stirred to dissolve. After coating, drying and curing the permeability was 0.1 dry and 154 wet.

' Trade-mark Experiment 6 A solution of 5.454 g. of "SR 9020", a propoxylated glyceryl triacrylate with a reported molecular weight of 428, obtained from Sartomer Corporation, was prepared in 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 stirred 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 "Ebecry180", a polyether tetra acrylate with a reported molecular weight of 1000, obtained 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 stirred to dissolve. After coating, drying, and curing the dry permeability was 6.3cc and the wet permeability was 224cc.

Experiment 8 A solution of 6.457 g. of "Ebecry13720", 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 standing at ambient temperature for one hour, 16.622 g. of itaconic acid was added. After coating, drying, and curing the dn' permeability was 0.2cc and the wet permeability was 62cc.

Experiment 9 A solution of 5.399 g. "SR 360", the triacrylate ester of tris (2-hydroxy ethyl) isocyanurate, molecular weight 423, supplied by Sartomer Company, was prepared in 70 g. of Dowanol PM. To this solution was added 11.339 g. of Z-6020, and after standing one hour at ambient temperature, 17.262 g. of itaconic acid was added and stirred to dissolve.
After coating, drying, and curing the dry petmeability 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 in 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 stirred to dissolve. After coating, drying, and curing the dry permeability was 3.6cc and the wet permeability was 144cc.
Experiments 11-13 illustrate the effectiveness of the mixture of itaconic acid with Michael addition product of gamma aminopropyl triethoatysilane with various acrylate esters in providing barrier coatings on polypropylene film. The molar ratio of silane:acrylate ester:itaconic acid in these experiments was 4:1:8. The substrate as weU as the coating, drying and curing conditions WO 98/31720 PC'TBE98Mn006 were the same as those used in Experiments 1-12 and which are described above.
Experiment 11 A solution of 5.260 g. of "SR 295", pentaerythritol tetraacrylat,e, calculated molecular weight of 352, supplied by Sartomer Company, was prepared in 70 g. of Dowanol PM and 13.206 g. of gamma aminopropyl triethoxysilane, supplied by Union Carbide Corporation (Danbury, CT) as "A-1100", was added. After standing at ambient temperature for one hour, 15.534 g. of itaconic acid (obtained from Aldrich Chemical Corp.) was added and stirred to dissolve.
After coating, drying and curing the dry petmeability was 2.9cc and the wet permeability was 235cc.
In a 250 ml beaker was prepared a solution of 4.863 g. of pentaerythritol tetraacrylate in 70 g. of dry isopropanol and 12.21 g. of gamma-aminopropyl triethoxysilane, (A-1100, obtained 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 stirred 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 curing, the dry permeability was 0.2cc and the wet petmeability was 88cc. The dry coat weight was 2.9 g. / square meter.
In a 250 ml beaker, a solution of 3.822 g. of pentaerythritol tetraacrylate in 70 g. of isopropanol was prepared, and 11.505 g. of N-(gamma trinmethoxysilylpropyl) diethylenetriamine supplied by OSI as A- 1130 was added with stirring. The solution was maintained at ambient temperature overnight, and 14.673 g. of itaconic acid was added. The grey precipitate was stirred until a clear solution was obtained. The solution was diluted to 25 weight percent solids using dry isopropanol, coated and cured as described. The dry coat weight was 3.15 g. /
square meters, the dry permeability was o.lcc and the wet permeability was 44cc.
In a 250 ml beaker a solution of 3.381 g. of pentaerythritol tetraacrylate in 70 g. of isopropanol was prepared, and 14.847 g. of bis-(gamma trimethoxysilylpropyl) amine (A-1170, supplied by Osi) was added with stirring. The solution was maintained at ambient temperature ovenught, then 11.322 g. of itaconic acid was added and stirred until a clear solution was obtained. The solution was diluted to 25 weight percent solids with dry isopropanol, coated, dried 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.

Experiment 12 A solution of 11.628 g. of "Ebecry1220" (described in Experiment 10) was prepared in 70 g. of Dowanol PM, and 10.278 g. of A-1100 (as described in Experiment 11) was added.
After standing for one hour at ambient temperature, 12.094 g. of itaconic acid was added and stirred to dissolve. After coating, drying and curing, the dry permeability was 4.4cc and the wet permeability was 58cc.

Experiment 13 A solution of 7.398 g. of "Ebecry140", 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-1100, and after standing at ambient temperature for one hour, 14.379 g. of itaconic acid was added and stirred 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 filnt.

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 stirred to dissolve. After coating, drying, and curing, the dry permeability was 0.1cc and the ivet 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 penneability was 0.05cc and the wet permeability was 22cc.
Experiment 16 illustrates the effectiveness of the Michael addition products of mistures 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 WO 98/31710 PC"TBE98In0006 Experiment 10, where the same components were used but itaconic acid was included).
Experunent17 A solution of 10.492 g. of "Ebecry1220", (described in Experiment 10), was dissolved in 70 g. of 5 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, dried, and cured.
The dry pesTneability was 380cc and the wet petmeability was 294cc.

Experiment 18 illustrates that the concentration of the solids in the coating solution affects the 10 permeability of the resulting coated film.

Experiment 18 A 40 weight percent solids solution of the Michael addition product of Z-6020 and pentaerythntol tetraacrylate with the proper quantity of itaconic acid to provide a molar ratio of 4:1:10.4 15 (silane:acrylate:itaconic acid) was prepared by dissolving 5.432 g. of "SR
295" in 60 g. of Dowanol PM, and then adding 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% soluuon with Dowanol PM. The perrneabilities are described below.
Coating Drv Permeabilitv 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 barrier coating for film, but that the coating cracks and is undesirable as a barrier 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 stirred to dissolve. After coating, drying, and curing the coating appeared to be somewhat brittle; a sample exhibited many smaIl cracks rendering it unsuitable for use as a barrier film.

Experiment 20 Illustrates that barrier coatings can be prepared using simple mixtures of Z-6020, acrylate esters, and itaconic acid. These results show that aIIowing the Michael addition to proceed before adding the itaconic acid is an optional requirement.

Experitnent 20 A solution of 15.395 g. of "SR 295" (described in Experiment 11), was prepared in 70 g. of Dowanol PM, and then 12.131 g. of itaconic acid was added and stirred to dissolve, and 6.46 g.
of Z-6020 was added. The solution was coated immediately, and after drying and curing, 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 barrier coating is illustrated in Experiment 21.

Experiment 21 A solution of 30.79 g. of "SR 295", (described in Experiment 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 stirred to dissolve.
After coating and drying, the samples were subjected to the electron beam at the conditions described below in Table 1 and the following results were obtained.
Table 1 Dose Optimization Pe eabi itv AU <50ppm (02) Voltage, KeV Dose, Mrads Drv 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 w0 98/31720 PCrIBE98roooo6 Experunent22 Experiment 22 illustrates the effect of electron beam doses and voltage on another representative barrier 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 stirred to dissolve. After coating and drying, the samples were subjected to the electron beam conditions described in Table 2 below and the following results were obtained.
Table 2 Dose Optimization Pe a "
Vol e, KeV DoseLMrads Qry 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 0.02 67 170 2.5 0.3 43 170 5.0 0.1 95 170 10.0 0.1 116 Air 170 2.5 0.09 84 170 5.0 0.2 212 170 10.0 0.3 87 Experiment 23 -Various additives can be included in the compositions of the present invention to achieve improved barrier 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 comprising Z-6020, pentaerythritol tetraacrylate, and itaconic acid. The order of addition of each component is listed, and the components were added sequentially in the appropriate molar ratios as shown. As can be seen, the additional additives can improve the barrier properties of the film at high humidity.

WO 98l31720 PCT/B1i98/a0A06 Experunent24 As seen in Table 4, the coated films can give excellent barrier properties if the substrate is primed prior to the application of the coating. The priming solutions were prepared by weighing out the required quantity of primer material and diluting it with the required amount of the appropriate solvent as recited in Table 4. For example, a 0.1 percent polyethylene imine was added to 300 g. of isopropanol in a 600 ml beaker, and stirred to obtain a clear solution. The film substrates were primed by immersing the film in the primer 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 primer solution to drain completely and allow the solvent to dry at ambient temperature.
Experiment 25 As illustrated in Table 5, the excellent barrier properties can be achieved by the addition of a polyoxyethylated alkyl phenol to the coating solution prior to application of the coating solution to the substrate.
The wetting agent employed in the experiments described in Table 5 was "Eccoterge EO-100", a polyethoxylated alkyi phenol supplied by Eastern Color and Chemical Co. The indicated quantity of wetting agent was added to each solution by preparing the coating solution at 30 weight present solids in isopropanol and diluting this solution to 15 weight percent solids with isopropanol containing the quantity of wetting agent required to provide the amount indicated.
Experiment 26 The data in Table 6 illustrate that other compounds such as a carbodiimide (Union Carbide Corp., Danbury, Ct.) can be used as a primer for coating compositions of the present invention, and that compositions utilizing an added wetting agent can be successfully applied to primed film. The procedures followed for adding the wetting agents and applying the primers were the same as those followed for Experiments 24 and 25.

Experunent27 As seen in Table 7, additional additives and primers can be combined to achieve better barrier -properties. The procedures followed for applying the wetting agents and primers were the same as those followed for Experiments 24 and 25.

~ 19 o 0 o u 0 a ,~ GO

M N ~
., ~ ~ ~ z v~ ~' 3 ~ N w y C ro O
o " y ~I N a N O N
in O O O a' O O O
o ? 0 z ~ t0n ttl V v A
W
A
u; Ln t. ~
a= o~. 3~ ~ M~ M g N
v z z z z 3 a W
~ C J
s c ~
E Q p ~~~ a ~~ g a U p w + + ~ + + ~
N t (7 0~ N(~ < + N N+7 ~ C7 a a(7 C7 a. a X

Ul) coo N v a U
a= a= c e~ c a= v ~ca o 0 0 0 0 0 0 x u E ~ ~ ~ ~ N N N
0 p 0 u w u~ y0 a F F F F F F(dr-p o V - d d d ~ d d ~ p ld U!

o tn a y ;b N "'~ =(V y a~+ a~+ a~+ a~+ i+ i+ a~r u ~
M
ci ci u u ci u a m C . o C m 0 m o m x N~ .d- v u a~ O~ a~ u A d d ti ~ o E E
> >, ~, 1, S A, p C 4W G. 0. p C7 C7 C7 C7 p C7 C7 (7 U o o = o 0 0 0 0 0 0 ~ o F O O O O O O ~ O O NO
t0 t0 t0 F$ N N N N N N W N N N

G~ d w N t- ao rn~ g tn~ n :3 o o+ o~ o+ o+ O o 0 d f!1 N N N N f M
~~ o a a a a a a a a a d y a ~

F
x ~N
GG o ~
O
O O g O
~/ ln If) 00 ~ C1 10 E ~~~ N N~~0 00 ' iA O~ t0 M l- N l, Q z M a' d' [~ lA t0 M C % 0 N N N 00 M
z .. ~ z O ~I N 0 a ~ N N~ r+ N N N~p N 00 N~ N O N tn O N O O O O ON cM M M~ O O O c0 O O N N O N
N -.
A N
A

LA Rt CC ~ d S 7 ~1 =
a!+I N~ N~ N c~1 N M M M~ M~ V M N M~ c'~ N N
z z z z z z z a a a ~
+ + ~ 0 +I v + + 0. + a + + + + + C7 + + + + ~ C7 N a c7 n C~ N~ N Q N~ ~~~~ ~ Q
a a + + + + + + + + + + + + +
4 ~ + d ~ Q Q + + + +
N + N N~ N N y N NN N N N
+ + + + + + +
C~ N N N N N N C7 a Ci G C7 + + +.. C7 + G + ci ;F C a' Y F 7 00 00 00 00 00 00 O O O O O O N N N N_ N_ N_ .. ,. ., ~
.. .. .. .. .. .. .. .. .. .. .. .. ..
N M M~' a' N t0 N N M M~~
.. .. .. .. .. .. .. .. .. .. .. .. ..
~ Q~~ d~ d d d d~~~
Eõ E- F F F E- E- E- F F E~ F F
a' d a' c d d 0 0 0 0 0 ~~ ~ d~ d~ Q d d~~ d d~ O O O O O O N N N N
.,. . .. . , , . .~ ~ 7 .!
ti .. . .. .. ..
a a a a a a a a a a a a a a'" ~'" ~~~'0 '~ i0 '0 N V' ~ ~ N N
6~ i1 ~+ a+ ~+ a+ ~ ~ ~ aU ~ v a+ a+ ++ ~+ a+ '+ a, ~+ a C 7 y a' d' d' ~d~d-d~~~
a u u u u a u u u u n u x x x~ x x~~~ x~ x~
a+ ~r +r +r a.~ a+ ~+ ar ~r w w ~r u u a~ a~ a~ V UU
E 5 E E E E E E E s E E a a a a a a'. a a\. a a >, o 0 0 0 0 0 0 0 0 0 ;o ;o ;e ;o ;a ;o ;v ;v ;o ;e ;o ;o ;v b ;a ;o ;o ;o b ;a ;o ;o ;o 0 0, ~
C7 C7 C7 C7 C7 C7 C7 C7 C7 C7 C7 C7 C7 C7 C7 C7 t7 C7 C7 C7 C7 C7 C7 O o O O O O o 0 0 O O O O O O O O O O 0 O O 0 N N N N N N N N N N N N N N N N N N N N N N N
O O O O O O O O O O O O O O O O O O O O O O O
~0 ~0 ~O t0 ~D t0 t0 D ~O ~0 t0 D 0 ~0 D D 0 0 ~D t0 ~0 ~D ~0 ~~ NN ~ ~ ~ ~
N N N N N N N N N N N N N N N N N N N N N
tlk 00 N M V N M O% ~ 1p 00 C~ ~ N M eh t~ m O M tA
~ O N N N N M M O~ M M c~ M O O O O M M~ N -+ ~
M M c~) M M M M M M M M M M M M M M M M M M M M

H H Ea-F F Ea-F FaF F F F F F F F F F F F F F F F

WO 98/31720 PCT'BE98100006 = o O
QO
a o 00 0 a, Z

n H I o ~ o Nko 0 0 A
a & N '~ N M
~ z z z ~ a wa rz wd+a +
~ ~ ~ 2 a N N a a N N~
a a N N C 0. N
m y ;F a' 0 0 '"
N N -0 o N N
V) IA N NIT a' IT
N N O O O O O
00 00 ~, =r =~
N N F N cV 4 c!~ M F~ fd~- F F
F E ~, w d a W W ~ a a d d , u _~ =~ ~ .C .C 4a1 N N
wwmmm O O O O O O O
N N ~ N N N N N

lS N O N N N N N

M CO lA ~0 d ~f ~=+ tA In In M M M M M M M
F F F E F F

Vl .
., O~t O O t0 '=+ N~
0p CO tA M N M N N
x x .~
~~! M~A M t~ ~ ~f N N = C
a~~ o 0 0 0 0 0 0 0 $
..
F m 0 w ti .. ,E ~

N N
a a o~. ' E ~ o >
w v -~- E~ c 4~ ~ v Y lC cp ro c0 L w ~ Y Y G
>> 3 3 a a~ a, E N a ~''~~ E E E ? Y
a < a _- a a a a Y~ c u C C.~ .~ C C_ C'C r M >
õ O, p, ~ N E E E y N
.. tn ctl ~~~0 ~
N N o 0 0 o a a N~
\ \ ., ., .. .. .. p . Q O ~ t4 M= O O O O O O O= N c,i N
M
N
M
N N N~ N~ a~~ a N
~ N M
O C O O O lz F
0 E~- F F F Ed- F F F F F

Wa Wa aW Wa Wa Wa aW Wa aW ~
N N N N N N N N N 0 O O O O O O O O O 0 ~0 ~0 t0 ~D ~0 ~0 ~0 ~D ~0 ~0 N
N N N N N N N N N N
ro =v Y
." ~+ N N ~ p iA U7 tA ~0 t~ 00 N N M L
q~ N N N N N N In II! ln U) a M e? c~ M c? e? M M M 16, E-~F F F F F F F F F 3 O
y WO 98/31TZ0 pcr/gE"p0006 x ~ ~0 N 0~0 10 ~

~ N L-1 N0 O O O O N~

,~ c. s a~ a r a a aV av ab a~ u a~ u v m u f0 v f0 v m Y 0 w 0 0 c 0 l0 u r u: u r v >, o a=p c= c -'' c ~ a 0 0 o S o Ln ca 31 ~ o~ o~ o - o x O

G

U
m w rNi rNi ~t a; rNi rNi a 0 0 0 0 ..
vi vi == =, vj vi ..: . .:; .:. .. ., .
N n V v tt' y e+ n.~
F F F F F F
~(~ a~~....Q((..yy (a~~(((y..yy a(~ d((~~ a(~ v W W
M W~ a. WIL a WWW CL a 0.
C O O O O O O O
O O O O O O O O ~
U N N N N N N N N V
u ~ N N M M~ d~~ a ~ M M c~ c~ M M M M ~
a F F F F F E'- E- E-N

WO 98/31720 pCT/BE98rom Go C~) N M N N M
N
N -+ O 0 0 M
O M 0 0 l~ 0 0 l-N

~ N
Ln ao o+ rn ~
N M N N N M
Z

U
N o 0 c c Ln 0 N
Ln v N C. G. O

%0 E :2 E N '-u o o o a E f0 A (0 \ U \ a 0 p a o ~ \ C. G :G o 0 3 0 3 y cv E u 3 3 a~ a c ., õ
Cl.
O O a. E
b y ~ a a o w ,,a, v w a~ ~n w w; a .o A v a n. m n w c a b a ~ ., c o o n.
c o c a O C
~ a o Ln o o b o~ uci N ~
~ .. .. ., ~' ., N
o ~ m~t m~' m d ~ et =, o A c A~ A bp A[r o A A a r-i V uFi t~ vEi ~1 uFi W~/) cNV rFn N w U~? a >
M f~ M C~ f? ch M
GD F Ea- F E~-Ea- F F ~
'd U

N IA tA
tA
N N M N ~t et ~ M M d M

~ 00 N IA
~~+I OtA " M N N tA N -+ a D N
~ a~+ O O O O d N o Ci oG c'ri O
.. .+ .-~ ,.~ . , U -O N O N 2M2 N M ch z z z z Y
~ ~ Q ~ ~ ~ d ~
a a a c c c ~ c (7 C7 C7 C7 C7 N N N < ~ ~ <
~
V ~- +'S+. a G+. ++~ N N N N N
I + + + + + 2 2 2 + + + + +
N N N N N C7 C7 C7 a. a a a O O
C
0 0 ~
C C C 0 y c a a a a a a ~ v v a~i v E
n ia m m m m ' a ' a E
a a o E a E a E a E e E o E 0 ~ u .' ~ ,~c =' r ~ U a>' Q
a a a a a a o. a E a. n a. E (L
o~ o a o 0 0 ' ~ ~ o' o õ .. . w .. ~ .. W .. .. _ ..
o o O 0, o o o fL O o 0 0 0 0 b Ln uO Ln U) a~l p 9 vl 0 ~ 0 ~ N N N N N
y . .
0 o a o 0 0 0 0 ~ 0 O
d d Ln N N
+ U) N N N N N N N Nõ
~
a' C' V, ;F t W 6 00 ~0 D :~ =:
O O O O O N N N

d .~r E-~ F F d d d d ~
F F F F F d E~. aE EQ. ~E- aEaF. aE. <E- CL, ~
W W W W W W W W o 0 0 0 0 a a a a a a. a a c c c ~o \ \ \ \ \ \ \ \ U U U U U
O \ \ \ \ \ \ \ \ \ \ \ \ \

N N N N N N N N N m N u1 N v! N dl N 0 O O O O O O O O O 0 ,0 0 '0 O'd O T!
Q ~0 10 10 ~0 ~D 10 ~D ~0 ~0 ..~~0 ~D :~ 10 ~+ 0 0 U N N N N N N N N N~i t5 ~i N~i N~ N m O ~'~ N r+ N
,.V, tp r+ C~ 1f) ~p M M lq 00 N N N
M ~0 N W ~0 ~0 10 t0 If) M M M M M M c? M N) M M M
~q p~ a a a a a a a a a a a a aG E= F F F F F F F F F F F F

a 26 N

' z H al o z 0 ~ a ~
N
O
a v w b a o +
w Q
~ + +
a a w ~
~ W m v o o a c C q a~ C
a ca c7 E
~
c d z E ~
V
. E

$ o a "
r~ (='.
Q ,N
N
~
o ~ c7 ~
cv o N o d et n a N
Q b b a a a b b u U
=~' C7 C7 F
p p ".C II C
O q0 O
U N ~i N ~ '~n o "

~
Wa M M u r~ F F w a ~

W0 9IV3ino ~IBE9"M

Experiment 28 This comparison example shows the barrier values of a coating including coltoidal silica. A
mixture of 1.08 g of aminopropyltrimethoaysilane, 25.36 g of isopropyl alcohol, 1.36 g of hexanediokiiacrylate and 3.79 g of trimethoxypropanetriacrylate was stirred at room temperature for 72 hours. To this mixture was added 0.23 g of aerylic 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 thiclmess of approximately 5mu with a #4 Myers rod. The samples were UV cured using a Fusion h bulb (360-365nm), 300W/in power rating, delivering a dose of between 300 and 500 mJoules. The wet barrier values are shown in Table 8 below. The samples showed extremely high oxygen transmission rates.

Table 8 Sample Corona treatment OTR 80% RH Average OTR
1AHS High 468 526 2AHS high 585 1ALS low 631 690 2ALS low 750 Experiment 29 PETA and Z-6020 were first reacted for an hour in the each of the respective solvents Gsted 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 in a moist oven, at 90"C and for 10 minutes. The coating was then EB cured at 170kV and 10Mrads. The data variations were not large. The speffic results are set forth in Table 10 below.

Table 10 Formu i n Solvent CW fg(n12j 0%RH OTR 80-0/qRli OTR
IccIm!djYj Icc/m2 av1 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 iIIustrates that the coatings of the present invention can provide reduced oxygen 28.
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 irradiation.
For the 1:1.5 formulation, a solution of 30.79g of SR295 (PETA Sartomer) was prepared in 1 12g 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 stirred to dissolve. After coating and drying, the samples were exposed to electron beam irradiation.
For the 4:1 / 1:1.5 blend, both solutions were prepared as described above, then mixed 1:1, coated, dried and electron beam irradiated.

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 PET (50mu) 1:1.5 6.8 14.8 PET (50mu) None NM 21.4 Experiment 31 The foAowing experiments illustrate that the order of addition of the aminosilane, ethylenicaIly unsaturated acid and multifunctional acrylate components are not critical.

"Semi-Ouenched" 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/m2 was coated on OPP to give 9.1cc at 0%RH and 27cc at 80%RH.
The film was initially primed with 0.1% polyethylenimine. 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.

"Ouenched" 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 obtained. 2.9g/m2 was coated on 0PP to give lcc at 0%RH and 15cc at 80%RH.
"Ouenched" 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 stirred to dissolve and finaIIy 12.948g of Z6020 was added. The solution was coated and dried, and the samples were subjected to electron beam irradiation. 2.7 g/m2 was coated on OPP to give 126cc at 0%RH
and 157cc at 80%RH.

Experiment 32 A solution of 9.234g of SR295 (PETA Sartomer) was prepared in 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 stirred. After coating and drying, the samples were exposed to electron beam irradiation. A second solution was prepared with l Og of polvethvlenimine, having a molecular weight of 700M with 29.71 g of itaconic acid, and 92.66g of IPA. This second solution was added to the first to arrive 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/m1. Barriers at 80%RH were 60.9cc, 55.1ec and 80.7cc respectively.
The foregoing specification describes onlv the preferred 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 differing from the foregoing, do not depart from the spirit and scope of the invention herein described and claimed.

Claims (31)

Claims:

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 R1 is independently hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl, acryl, methacryl, alkylaryl, R2 -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 R1 is a hydrogen atom and at least one R1 is an R2 -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;
R2 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, wherein the ethylenically unsaturated acid is a dicarboxylic acid or a monoalkl ester thereof.

2. Composition according to claim 1, characterized in that the aminofunctional silane is N-(2 aminoethyl) -3 -aminopropyltrimethoxysilane or aminopropyltriethoxy silane, or mixtures thereof.

3. Composition according to claim 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 amino functionality of the aminosilane to the acrylate functionality of the multifunctional acrylate is about 2:1.

5. Composition according to any one of claims 1 or 2, characterized in that there 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 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 multifunctional acrylate is about 1:3.

7. Composition according to any one 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 urethane acrylates with molecular weights from 1000 to 2000;
polyether acrylates with molecular weights from 200 to 1500;
polyurethane 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, dipentaerythritol hexacrylate, and ethoxylated and propoxylated derivatives of the above.

9. Composition according to any one 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 is present in an amount of 1-99% and the solvent constitutes parts by weight of the total composition.

10. Composition according to any one 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 any one 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, itaconic acid monomethylester, and mixtures thereof.

12. Composition according to any one of claims 1 to 11, characterized in that the aminofunctional silane is N-(2-aminoethyl)-3-aminopropyltrimethoxysilane or aminopropyltriethoxy silane, the ethylenically unsaturated acid is itaconic acid, and the multifunctional acrylate is pentaerythritol tetraacrylate.

13. Composition according to any one of claims 1 to 12, characterized in that the molar ratio of aminofunctional silane to multifunctional acrylate is about 1:1.5.

14. Composition according to any one of claims 1 to 13, characterized in that said composition includes an additive.

15. Composition according to claim 14, 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 and polyethoxylated phenol.

16. Composition according to any one of claims 1 to 15, characterized in that said composition is coated on a substrate.

17. A method for forming a silicone coating comprising the steps of:

(I) coating a composition according to any one of claims 1 to 15 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.

18. Method according to claim 17, 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.

19. Method according to claim 18, characterized in that the electron beam radiation has an energy of from 5 KeV to 2 MeV and in a dose of from 0.1 to 10 Mrads..

20. Method according to claim 19, characterized in that the said composition is cured by electron beam radiation at 170 keV and in a dose of 10 Mrads.

21. Method according to any one of claims 17 to 20, characterized in that step (II) comprises heating the coated substrate of step (I) in the presence of moisture.

22. Method according to any one of claims 17 to 21, characterized in that the substrate is selected from the group consisting of polyolefins; polystyrene;
polyesters; polyolefin copolymers; polyamides, polyimides; polyacrylonitrile;
polyvinylchloride; polyvinyl dichloride; polyvinylidene chloride;
polyacrylates;
ionomers; polysaccharides; silicone; natural or synthetic rubbers; glassine or clay coated paper; paper board; craft paper; metallized films and vapor deposited metal oxide coated polymer films.

23. Method according to any one of claims 17 to 22, characterized in that the substrate is treated with a primer.

24. Method according to claim 23, characterized in that the primer is selected from the group consisting of a siline, polyethylenimine, and carbodimide.

25. The method according to claim 22 wherein the polyolefins is selected from the group consisting of oriented polypropylene (OPP), cast polypropylene, polyethylene and polyethylene copolymer.

26. The method according to claim 22 wherein the polyester is selected from the group consisting of polyethylene terephyhalate (PET) and polyethylene naphthalate (PEN).

27. The method according to claim 22 wherein the polyolefin copolymer is selected from the group consisting of ethylene vinyl acetate, ethylene acrylic acid, ethylene vinyl alcohol (EVOH), polyvinylalcohol and copolymers thereof.

28. The method according to claim 22 wherein the polyamide is selected from the group consisting of nyon and poly-meta-xylylene adipamide (MXD6).

29. The method according to claim 22 wherein the polysaccharide is regenerated cellulose.

30. The method according to claim 22 wherein the silicone is selected from the group consisting of rubbers and sealants.

31. The method according to claim 22 wherein the metal oxide is selected from the group consisting of AIO x, SIO x and TiO x.