CA1190894A - Method of sealing a glass container with a thin membrane closure - Google Patents

Abstract

Abstract of the Disclosure This invention relates to a method of sealing a container mouth, and especially the mouth of a glass container, and the glass container so sealed. The method involves oxidizing the container rim portion, applying a first annular thin cooting of an organo-functional silane compound and then a second annular thin coating of an ethylene acrylic acid copolymer over the first coating on the rim portion. A thin imperforate membrane such as aluminum foil having a thermoplastic sealing material such as Surlyn copolymer over its sealing surface is sealed to the container rim portion with heat and pressure.

Description

The present in~ention relates to the preparation of a glass sealing surface for sealing to a thin mem-brane capable o~ effecting a liquid-tight seal. The method is especially useful for sealihg the mouth por-tion of a glass container which has been treated tofacilitate durable and long term sealing preferably by means of a laminate of aluminum ~oil and a thermo-plastic polymer.
It i5 fairly common to form hea-t-activated seals on plastic containers using thin membrane type sealing materials. Generally, a membrane, which may be com prised of a laminate of aluminum foil and a thermo plastic polymer is forced against the mouth of the plastic container under heat and pressure so that the container and sealing laminate form polymer-to-polymer adhesive contact. While the method is of considerable bene~it in sealing plastic containers, it cannot be used in sealihg glass containers since only short-term seal li~e can be obtained unless a supplemental closure

2~ is employed. Poor adhesion between the polymer and the glass results in leakage especially in packing many types oE hot fill and acidic products.
The present invention provides a method of sealing a container mouth, the mouth consisting of glass and having an upper rim portion, which comprises the s-teps of heating at least the container xim portion to an elevated -temperature to oxidize any existent materials thereon, applying a first thin coating of an organo ~uctional silane compound to the rim portion, applyiny a second thin coating of an ethylene acrylic acid co-polymer over the first thin coating of the silane compound on the rim portion, pressing a thin imper-iorate membrane comprising a thermoplastic sealingmaterial against the said second thin coating of ethylene acrylic acid copolymer, and heating at least the xim portion to a temperature above ~he softening point temperature of the thermoplastic sealing material to seal the thin membrane to the rim portion in liquid-tight relation.
In a preferred embodiment of the present lnven-tlon~ the sealing surface of the mouth portion of the glass container is initially flame treated to oxidize any and all surface coatings which may exist thexea-t.
Such coatings may be present where the exterior sur-faces of the container body portion have been treated with thin films of metal oxide and lubricou~ organic materials for example. The mouth or rim portion of the container is next treated with an organo-~unc-tional silane compound applied over the heated rim sl~rface in a fully annular pattern and then treated with a second coating of an ethylene acrylic acid copolymer which is applied over the cooled surface in a similar annular pattern. The silane and copolymer treatmen-ts are conducted successively in the stated order aEter which the container is ready to be sealed with a thin imperorate membrane.

.

The seal is formed, after filling the container with product, by pressing the thin imperforate membrane comprising a film layer of thermoplastic ionomer material such as Surlyn over the sealing surEace and heating the thermoplastic ionomer material -to form a strong glass to thermoplastic adhesive bond. The thin membrane preferably is comprised o an aluminum foil/
thermoplastic film laminate although it may also be comprised o~ paper~polymer laminate, a polymer sheet or a laminate of two or more layers of polymers, metal foil and/or paper. The only requirement is that the polymeric material of the thermoplastic type face the annular pattern of the preferred-ethylene acrylic acid copolymer on the container sealing surface for heat and pressure sealing compatible with the contained product.
Thus, a specific ohject of the present invention is to provlde an improved method of preparing the seal-ing surace of a glass container to form a more durable li~uid-tight seal. This may be effected by first heat-ing the sealing surface such as by flame treatment to oxidize the material existent thereon, coating the sealing rim surface with a thin coating of an organo-functional silane compound, and then applying a second ~5 thin coating of a thermoplastic ~thylene arcylic acid copolymer. The sealing surface may then be sealed, after filling the container, using a -2a-thin imperforate membrane having a ~hin coating of e~hyl~ne acryl~c acid ~opolymer over ~t~ sealing ~urfacer the rim portion of the container being h~ated ~bove the softening point temperature of the ~atter thermopla3tl~ sealing mateial to effect the va~uum-tight ~eal. Thus, a durable long-lived liquid~
tight v~cuum seal is achieved by ~he pla~tic to-glas~ bonding.
Preferably, a method of closing a glass container is employed in which a dual-layer adhesive coating is placed on the rim of the container and a thin metal foil having a thermoplastic sealing layer thereon is pressed against th~
container rim employing heat and pressure to efect the seal.
With regard to the ~ealing of glass containers it i5 known to use metal foils such a~ aluminum h~ving a thermoplastic coating thereon and applying same to the containex mouth employin~ heat and pre~sure. I~ thi~ process the foil is pressed against the container rim for a sufficient period of time for the thermoplaskic coating to adhere to the oontainer rim. Normally either conduction or induction heating is u~ed for such ~ealing to ~oin the met~l oil to the glass; however~
such ~al~ are only practical for dry Gontents and not liquids filled by hot-f~ll technigues. Further sealing materials must be u~ed which are approved ~or such sealing purpose ln con~ac~
with a wide v~riety of ood~tuff~ and bev~rage~, While lt is known to use a ~ilane material on the glass .rim for ~ealing purpose~ to a metal foil, ~he adhe~ion a9entB prevlously dlsclosed are eith~r not approved for food use, or present a ~ti~ky or t~Cky eondltion not readily storabl~ ~lthout ~pecial care, or requirlng an undue t~me del~y for ag~ng beore acceptable sealing. 5uch u3e of a silhne i6 broadly dl~closed in Wes~ German Pa ent Document P 28 33 334.~23 publi~hed ~une ~ 15~15 23, 1979 to Gerre~heimer Glas A~Go ~rie~ cri~tion of the ~rawin~
Figure 1 is an exploded view of the metal foil/thermoplastic film membrane and snap cap for sealing a glas~ container~
Figure 2 is a fragmentary ver~ical sectional ~iew of the upper portion of a glass container illustrating the metal oil~thermoplastic film membrane seale~ ~o the sealing surface of the container with the snap cap in place.

This invention relates to the preparation of a ylass container for use with a seal of the membrane-closure type which is liquid-tight to erve as a replacement for the conventional ~crew cap clo~ure for glass containersO A thin strong membrane preferably consisting of a metal foil laminate having a layer of thermoplas~ic polymex thereon i5 heat seal2d to the sealing surface at the mo~th of the glass container.
Heat sealing is normally accomplished ater filling the container by forcing the thin membrane against the glass sealing surface or lip area at a temperature slightly above the ~o ~oftening point temperature of the thermoplastic material but pr~erably b~low the melting point temperature. Either conduction or induction heating may be employed to at~ain such heat sealing u~ually within a ~hort period of time where a heated platen is u~ed~ After effecting the final seal ~he m~mbrane can be covered by a plastic snap cap for protective and r~sealing purposesO
It has been found that in many common types of such sealing, problems of ~eaka~e can occur e~p2cially ir ~he p~ckaging of hot~
fill and acldic type products partieularly s~ored in high humidity condition~. Many dif erent types of coating materials have been em~loyed ~o attempt to eliminate these problems however r vir~ually all have been unsuccessful until the advent of the present proces~. Also various processes of treating the glass surfaces using sulfur oxides or decomposable fluorine compounds have been tried as disc~o ed in U.S. Patents 3,249,246 and 4,260,438. All of these method w~re directed at improving the sealing surface of glass containers using fluorine or sulfur oxide treatments to improve the strength and stability of the glass to polymer bonding. All re~uire extensive processing steps and exp~rience at least some leakage in providing liquid-tight long-term seals.
In accordance with the present invention a vacuum and liquid-tight seal capable of lsng-lasting storage can be provided to the mouth portion of a glass bottle or jar using a thin sealing membrane. The ~eal is formed by initial oxidizing treatment of the gla~s sealing surface to oxidize or remove any exi~tent materials thereon. Glass containers which have been surface treated over the exterior surfaces of their body portion with combinations of thin transparent coatings are 50 subjected to oxidizing conditionq. Frequently such containers are previously surface treated with combinations of tin or titanium oxides applied in the form of so-called hot-end treatments while the .
containers possess considerable heat of formation, and polyethylene, oleic acid or other organic coating materials applied in the form of ~o-called cold~end treatments. The containers, preferably wide mou h bott~es and ~ars, are conducted under a lineal eries of ribbon-type gas ~urner~ which produce an oxy~en rich gas flame to oxidize or burn off the organic constituent~ of the afore~aid ~reatments on the upper lip or so-called fi~i~h portion of the contain@rs thus making them water receptiqe or e~sentially hydrophilic at ~uch area.
The con~aineEs are heated to a ~empera~ure of up to about ~ 9 L~ 15515 180F,, at the finish portion during ~his phase of the process to accelerate the sxidation and hasten the drying of subsequent coatings to be immediately applied. The gla55 containers may have a finish area desi~ned wi~h a flat or crowned sealing surface adapted to accep~ a hea~ sealO The flame treatment of the finish area serves to modify and partially remove the ~urace treatment in that area.
The heated containers then pass under an overhead roller coating device consi~ting of a cylindrical rubber or other resilient material roller which is able to forc2fully contact the container lip portion during its passage therebeneath. The roller is mounted transversely of the direction of container travel and i.~ a~apte~ to apply about a Ool to 2 percent -~olution b~ wei~ht of an organo-functional silane compound in deionized water. Two such rollers are used mounted in adjacent relation over the container path. The containers are rotated through 90 degrees bet~een each application. Two applications are used ~o ensure complete and thorough coverage of the l.ip area especially in cases where the lip is not truly planar but possessive of minor dips or valleys. The dual application is pre~erred although a single application may suffice upon proper selection of roller facing material and certain types of container finishes.
A preferred ~ilane compound i5 Union-Carbide organo-functional Sil~ne A-1120, N(beta-aminoethyl) ga~ma amino propyl-trimethoxysilane, which is a diamino-functional ~ilane coupling agent used over a broad range of adhesive application~O It is manufactured and sold by Union-Carbide Corporation7 Silicone Divi~ion, Danburys Connecticuk~ This product is solubl~ in ethanol, methanol, benz~ne toluene, methyl oello~olve~ and in water when hydrolysis oecur~. It i~ us~d as adhesion promoter ~ 15515 in cer~ain plastisol sealants and as an addi~ive to phenolic binders and molding compounds. It is a straw-colored li~u.id having a specific graYity of 1O03 (25/25C) t a refractive index of 1.448 (nD25C1 and a flash point o~ 280F. The produc~ is dissolved in deionized water to give a one-percent solution, which is then delivered to the roll coa~ers. The silane coupling agent is applied as a ~hin film over the lip sealing surface, ~nion-Carbide A-1120 being preferred, although products A-llO0 and A-174 are al o suitakle silanes for this purpose.
The containers are then force coole~ and dried at a temperature of about 100~, and no~ in excess of abou~ 140F.
The initially-coated silane-bearing containers are then passed under a second pair of overhe~d roller coaters which apply a coating of bonding ayent over the ~ilane coating.
As in the ca~e of the application of the sil~ne the containers are successively passed beneath the pair of roll coaters mounted in tandem in close proximity. The containers are again rotated 90 degrees between each application to ensure that the bonding agent fully covers the first silane coating and does not miss a low spot on the container lip area. The bonding or adhe~ive agent preferably consists of an ethylene acryllc acid copolymer in the form of a water emulsion. A Dow EAA
dispersion which is called Polyethylene No, 483 made and sold by Dow Chemical CGmpany, Midland, Michigan, has most desirable 25 property pr~f iles . This ~AA coating combines the stren~th and ~bemical resistance of polyethylene and the high degree of adhesion and fun~tionality of free carboxylic acid groups. The dispersion offers ex~eptional performance advantages in priming and laminating operation~. The EAA material as applied comprises about a 25% by weight solids ~i~persion in water.
The material bonds and ~eals at relative1y low temperature~ and proYides flexible coatings high in tensile strength, clarity and glo~s. The coating provides ~xcellent wa~er resistance and outstanding adhes~on to me~al foil, paper, nylon and polyethyleneO ~he material al~o complies with FDA regulations for paperboard coatin~s and adhesives. In aadi~ion, the material is an inherent fllm former requiring no supplemental heating other than'that required ~o dry the applied coatings.
As stated, the heat-softenable Dow EAA product ~ethylene acrylic acid) ethylene copolymer i~ applied as a sec~nd thin film over the silane treated finish. Dow Polye~hylene 483 and similar products are suitable adhesive materials~
The silane coating is ex~remely thin being applied from a dilute ~queous dispersion. The second coating of EAA
dispersion is thicker having a thickne~s ranging from about 2 to 20 microns, although a narrower intermediate range of thickness of about 5 to ll microns is preferred. The dual coating is fully contiguous with and uninterrupted over ~he annular lip area.
In addition to the use of the EAA dilute disper~ions as the bonding agent/ a hot melt material ~uch as Product No. 3746 made and sold by 3M Company, St. Paul, Minnesota may be similarly employed as a coating over the silane material. While the EAA
material is pref~rred the hot melt material can be used as an alteEnative ~o provide comparable results.

Th~ particular bonding agent may require a orced drying and a cooling step before the container~ can be palletized or placed in a carton for ~hipment. ~he u~e of a hot mel~ ive would not re~uire a drying step as ~ay be ~he case with ~AA
di~persions.

The coated containers bearing the fir~t and seeond coa~ings over their lip regions are then transported to the product ~8--~ 15515 filling line for subsequent proce sins. The coated finish area of the con~ainers do not require ~ny special handling or protective covering techniques~ and may be stacked as necessary or desired in conve~ional processing~
Either cold or hot filling ~echniques may be u~ed to fill the containers with product. Al~o products which are considered somewhat difficul~ to pack with liquid-tight seals such as citric juices can be packed with the present proce~s providing long~lasting storage life.
The containers are filled with the selected product which may be at an elevated temperature ranging from about 190 to 210F., for example. A preshaped Surlyn-coated aluminum foil laminated lid is preferably use~ to ~eal the containers. The lid has a recessed central panel comparable in diameter to the container mouth diameter, and a thermopla~tic 6ealing material such as a Surlyn ionomer resin over i~s sealing surface.
The Surlyn material is preferably a duPont Surlyn Grade No.
1652 of the zinc type having a melt index of 5.0 and an extru~ion melt temperature of 310C. (590F) which can be applied to a paper or foil substrate. While there are many varieties of Surlyn formulations, ~ubstrate adhesion is the key factor governing the choice of Surlyn ionomer resin grade. All of the zinc type ionomers show ~cellent aged adhesion to unprimed foil as well a~ paper ~ubstrates. All grades of Surlyn lonomer re~in are based on either zinc or sodium ionsO The zine ionomers are most de~irable where products high in water or alcohol content are to be packaged~ The ~odium ionomers generally have a higher moisture content than zinc resins and can exhibit a hazy film appearance on extended exposure to water. All grades of Surlyn ionomer re~in have superior oil resistance in eomparison to polyethylene and other common olefin ~ 34 15515 copolymersl 5urlyn Grade No. 1652 has good oil resistance and excellent toughness and abrasion resistance for packaging many types of aggressive productsO
The overall heat ~ealing properties of Surlyn ionomer resins are outs~an~ing and are generally characterized by low temperature sealability, high mel~ s~rength and ability to seal through contamination, broad sealing range, and high seal strength. Ionomers provide greater fusion seal strength than most polyolefin materials. The Surlyn Grade No. 1652 provides a Vicat so~tening point of 80C (176F) which is one measure of low temperature sealability. This resin has a heat-~eal interface temperature of 132C. (269F) and a melt viscosity at shear rate of 0.1 sec ~1 of 10 lb. - sec/sq.in. Grade 1652 has a low viscosity value and thus a high flow to assist sealing through liquid-type contamination. As stated, the zinc iono~ers provide higher seal strength at lower seal temperatures than the sodium re~in~.
Surlyn Grade No. 1652 i~ an extrudable ionomer resin which i~ a metal salt of an ethylene/or~anic acid copolymer of the xinc type available in pellet form for use in conventional extrusion equipment de~igned to process polyethylene resins.
5urlyn ionomer resins are approved under FDA regulations for use in packaging food~ subjec~ to extraction ~pecifications on the ~inished food~contact article. While ~he Surlyn ~r~de No. 16S2 is preferred~ Grade ~aOs. 1702 and 1705 which are ionomer resins for flexible packaging may ~l~o be used in the present inventlon O
The aluminum foil/thermoplastic ionomer resin laminate is employed to seal the container mouth using conduction or induction heating to ~often the Surlyn ionomer resin sealing layer and the bondin9 a9ent on the lip area so that ~hey f~se together in a Fusion type reaction. Sealing ~emperatures are effected in the range of about 330 to 420F. using heat and pressure on the lid lip area. A heated platen may be used ~o apply uniform top pressure of a~out 40 to 90 psi gauge to the ~lexible coated oil lid during the fu~ion cycle for a brief period of abou~ 1/2 to 1 1/2 second. The foil lid is preshaped with a central recess to assist in aligning the lid and to reduce stress on the bond as the seal and the contained product cools in the case of hot packingn The top pressure can be created by a capping machine supplying a combination of both heat a~d pressure. Following sealing of th2 lid to the container, the containers are cooled to ambient temperature desirably using a cooling tunnel which sprays progressively cooler w~ter onto the cor.tainers. The cool containers may then be checked for any leakage and labeled as desired.
An aluminum foil lid, or a lid of other flexible material with ~uitable barrier prop~rties such as Mylar film, coated on the side contacting the treated finish area with a heat sealable material~ maybe usea as the closure. A thin alumimum foil, coated on one ~ide with one of the Surlyn materials supplîed by duPont, is most desirable for the lidding material. Preferably the foil ha~ a 1 1/2 ~o 2 1/2 mil thickness. The foil can be also coated with an ~A bonding agent ~uch ~ the Polyethylene No. 483 applied OVeE the glass finish as an exterior coating, providing two similar materials for fusion bonding. The ~ubject ~ethod of sealing provides a practical heat-sea~able clo~ure for glass container~ for use with high moisture containing product5~ e~pe~ially product5 which are hGt-filled ~uch as citric fruits and juices.
Figure 1 illu6trate~ the var~ous components of the glas~
container sealing construction in disa5sembled relationO Figure 2 illustrates the compone~ts o the ~ealed container . The f irst layer or film 1 of silane compound is adhered to the lip area of the glass container G . The second layer or f ilm 2 of EA~
di~persion is deposited over ~che f irs~ layer ~ Metal foil membrane 3 has a Surlyn ionomer layer or film 4 which is fusion sealed to film 2. The me~al oil may have a paper or other coating 5 adhered to its exterior surface. The snap cap 6 may be optionally used to cover the foil seal.
Samples of ~he sealed containers have been tested under vacuum and been found to withstand more than 25 1/2 inches of mercury vacuum without leakage. Such samples w~re sealed using the aforesaid preferred sealing constituents as thin coatings intermediate the glass finish and an aluminum foil lid. As desired, the sealed container~ can be covered with a thermoplastic snap cap, such as those commonly made of polyethylene, which serves to protect the foil closure from puncture or damage and to permit resealing of the container.
Extensive sealing test5 have been made usiny wide mouth glass jars comprised of soda--lime-silica glass as ~he containers. Pint jars havin9 16 ounce capacity and a rounded crown~type lip ar~a were coa~ed s~ith the silane and EAA
dispersion coatingæ. The jars were first treated over the lip area with the 1% A-1120 silane and then with the ~AA coating having a 75 melt index . The jars were 'chen sealed using a 2 . 5 ~11 Surlyn coated aluminum foil made by RJR Archer Company, Winston-Salem, NC. The seals were made using a h~ate~ pla~en-head capping apparatu~ at about 400F over ~ period of about 1.2 seconds and at 85 p~ig pre~6ureO As stated, the ~ealing pressure can be varied from abouî 4Q to 90 psig.
Twelve of twelve jars which had been previou~ly filled with 210F. water passed test~ of 7 inches of mercury vacuum plus ~12-15~15 26 1/2 in~he~ of mercury vacuum ~lthout leaksO Such te~ts were conducted per iodically and successively and no leakage of the containers was obser1lred over a sub~antial period of time.
El~ven of twelve jar~ which had beerl filled with 210F.
orange juice passed the 7 inche~ of mercury vacuum plus the 26 1/2 inches of mercury vacuum tests. One jar pas~ed the 7 inches of mercury vacuum te~t but failed the 26 1/~ inches of mercury vaouum test when leakage was obaerved.
Further, twenty-one of t~7enty-one samples of illed and sealed glass jar~ coa~ed over ~heir lip area with silane and EAA
Product No. 483 having a 300 melt index which had been previously filled with 190''F. water were stored 169 days inverted in beakers in a 10ûF. room without leakage. Also no leaks were observed af ter 7 inches of mercury vacuum was applied.
The following water absorption results were obtained on several adhesive materials which have been considered for glass container sealing.
Glass slides were taken as the ~ub~trate for depositing the adhesives and measuring their watee absorptlon. The two materials compared were ethylene acrylic acid copolymer (EEA) and polyvinyl butyral ~opolymer (PVB), the former being the preferred ma~erial of ~his inven~ion.

Weight Gain Condition Materia~ Wt (1) Slides above water EAA 0.01 - 2 days ;~t 100F. PVB 0.6 ~) Slides i~nmersed ir: EAA -0O4 deionized water PVB 6 . 3*
- 2 days at 10ûF.
* (PVB range 3~ to 8.3) ( 3 ) 51ide~ above wa~er El~ 0 . 5 - 2 days at 31;F. PVB 1.1 ~].3--~3~9~894~

Thus, very little water absorption by EAA
coatings was obs rved.
In another experiment, coa~ed slides were immersed in denatured alcohol for 1 day a~ 100F. The PVB coa~ing was completely dis~olved and the EAA coa~ing was softened~
The sealed foil closure may have a pull tab at one peripheral region of its edge to acilita~e opening of the container. Normally the closure can be fully or partially removed by upward angular tensive force applied to the closure.
Various modifications may be resorted to wi~hin ~he spirit and scope of the appended claims.

Claims (22)

WHAT IS CLAIMED IS:

1. The method of sealing a container mouth, said mouth consisting of glass and having an upper rim portion, comprising the steps of heating at least the container rim portion to an elevated temperature to oxidize any existent materials thereon, applying a first thin coating of an organo-functional silane compound to said rim portion, applying a second thin coating of an ethylene acrylic acid copolymer over said first thin coating of said silane compound on said rim portion, pressing a thin imperforate membrane comprising a thermoplastic sealing material against the said second thin coating of ethylene acrylic acid copolymer, and heating at least said rim portion to a temperature above the softening point temperature of said thermoplastic sealing material to seal said thin membrane to said rim portion in liquid-tight relation.

2. The method in accordance with Claim 1, wherein the thermoplastic sealing material of said thin imperforate membrane comprises a thermoplastic ionomer material adhesively joined to the sealing surface of a thin sheet or foil selected from the group consisting of metal, plastic and paper.

3. The method in accordance with Claim 1, wherein the said container rim portion comprises the mouth extremity of a glass bottle or jar which is heated to a temperature up to about 180°F.

4. The method in accordance with Claim 1, wherein said container rim portion is comprised of a soda-lime-silica glass.

5. The method of sealing an imperforate thermoplastic film or metal foil to the mouth portion of a glass container comprising the steps of heating at least the mouth rim portion of said glass container to an elevated temperature up to about 180°F.to oxidize any existent materials thereon, applying a first thin coating of an organo functional silane compound to the heated rim portion of said glass container, cooling the heated rim portion of said glass container to a temperature not in excess of about 140°F., applying a second thin coating of an ethylene acrylic acid copolymer over the said first thin coating of silane compound, filling the said glass container with produce, pressing a thin imperforate membrane having a third thin coating of thermoplastic ionomer material against the rim portion of said glass container while heating said third coating to a temperature above the softening point temperature of said thermoplastic ionomer material, whereby said thin imperforate membrane is securely adhered to said rim portion in vacuum-tight relation.

6. The method in accordance with Claim 5, wherein said second thin coating of ethylene acrylic acid copolymer is applied to said rim portion in the form of a water emulsion.

7. The method in accordance with Claim 5, wherein said third thin coating of thermoplastic ionomer material is adhered to said membrane and comprises a metal salt of an ethylene/organic acid copolymer of the zinc or sodium type.

8. The method in accordance with Claim 5, wherein said first and second thin coatings are successively applied to said rim portion with resilient roller coaters adapted to uniformly press against said rim portion.

9. The method in accordance with Claim 5, wherein said first thin coating of an organo-functional silane compound comprises about a 0.1 to 2 percent by weight solids dispersion in water.

10. The method in accordance with Claim 5, wherein said second thin coating of ethylene acrylic acid copolymer comprises about a 25% by weight solids dispersion in water.

11. The method in accordance with Claim 5, wherein said imperforate thin membrane comprises a disk-shaped aluminum foil member having a recessed central panel.

12. The method in accordance with Claim 11, wherein said imperforate thin membrane has a pull tab at one peripheral portion.

13. The method of sealing a thin imperforate thermoplastic film or metal foil to the mouth portion of a glass container comprising the steps of heating at least the mouth rim portion of said glass container to an elevated temperature up to about 180°F., applying a first thin coating of an organo-functional silane compound to the heated rim portion of said glass container, said silane compound being in the form of about a 0.1 to 2 percent by weight solids in an aqueous dispersion, cooling the heated rim portion of said glass container to a temperature not in excess of about 140°F., applying a second thin coating of an ethylene acrylic acid copolymer over the said first thin coating of silane compound on said rim portion, said copolymer being in the form of about a 25% by weight solids in an aqueous dispersion, filling the said glass container with product employing either a hot or cold filling process, pressing a thin imperforate membrane having a third coating of thermoplastic ionomer material comprising a metal salt of an ethylene/organic acid copolymer against the dual-coated rim portion of said glass container while simultaneously heating same to a temperature above the softening point temperature of said thermoplastic ionomer material, whereby said thin membrane is securely adhered annularly to said rim portion in vacuum and liquid-tight relation.

14. The method in accordance with Claim 13, wherein said first and second thin coatings are successively applied to said rim portion with resilient roller coaters adapted to uniformly press against said rim portion.

15. The method in accordance with Claim 13, wherein each of said first and second thin coatings are applied with successive dual applications made at right angles to each other with resilient rollers to ensure continuous annular coverage of said rim portion.

16. The method in accordance with Claim 13, wherein said imperforate thin membrane comprises an aluminum foil member having a recessed central panel and the thermoplastic ionomer material comprises a metal salt of an ethylene acrylic acid copolymer of the zinc or sodium type applied to the sealing surface of said membrane.

17. The method in accordance with Claim 13, wherein said thin imperforate membrane is sealed to said rim portion with heating of the multiple coatings to a temperature ranging from about 330 to 420°F., and with a top pressure ranging from about 40 to 90 psig for a period of about 1/2 to 1 1/2 second.

18. A sealed glass container made in accordance with the method of Claim 5.

19. A sealed glass container made in accordance with the method of Claim 13.

20. A sealed glass container made in accordance with the method of Claim 17.

21. A glass container adapted to sealing its mouth portion with a thin imperforate thermoplastic film or metal foil comprising an open-mouth rim portion which has been heated to a temperature of about 180°F to oxidize the rim surface area, a first thin coating of an organo-functional, silane com-pound applied over the heated rim portion of said glass con-tainer, and a second thin coating of an ethylene acrylic acid copolymer applied over the said first thin coating of silane compound adapted to be sealed to said thermoplastic film or foil by heat and pressure to form a liquid-tight long-lasting seal.

22. A sealed glass container made in accordance with the method of claim 1.