CA1147614A

CA1147614A - Adhesive assembly

Info

Publication number: CA1147614A
Application number: CA000328490A
Authority: CA
Inventors: Theodore J. Sweeney; John G. Haviland
Original assignee: Sweeney Theodore and Co
Current assignee: Sweeney Theodore and Co
Priority date: 1978-06-09
Filing date: 1979-05-28
Publication date: 1983-06-07
Also published as: EP0016035A1; WO1980000029A1

Abstract

Abstract Described is an adhesive assembly containing a first adhesive and a second adhesive which is of a different chemical composition than the first adhesive and positioned between said first and second adhesives is a barrier means for preventing contamination of the respective adhesives of the substrates to which they adhere. Also described is a method of adhering together a plurality of substrates employing the adhesive assembly. Preferably the combination of the adhesive includes a spongy of foam layer.

Description

Descr ption An Adhesive ~ssembly Background oE the Invention The present invention is concerned with adhesives in general and to adhering a plurality of substrates.
It is well known in the art today that significant difficulties are associated with securing side body moldings to vehicles due to the method of adhering the moldings to the vehicles. Currently employed is a polyvinyl chloride molding. The industry has applied a plurality of hot melt adhesive beads on -the outer periphery of said molding with a bead of one component moisture curable urethane adhesive in between -the -two hot melt adhesives. The basic purpose of said technique is to have an immediate adhesion as the hot melt adhesive cools while a more permanent bond is effected as the one component urethane adhesive cures.
However, it has been found through experience that the adhesive system employed is not fully satisfactory. Also, if a pressure sensitive adhesive is used, the molding comes away from the body of the vehicle due to degradation of the adhesive and its adhering ability to the substrate by virtue of a delamination principle or by virtue of tha plasticizer that may be present; in the paint on the substrate or t.he plas-ticizer that may be present in the polyvinyl chloride molding itself.
Also, it has been found that the adhesion of the moldings to top coat paints oE the non aqueous dispersion type is very poor. Additionally, the transportation industry has been looking for a variety of means for decreasing the weight of au-tomotive vehicles as well as to save energy in the fabrication of vehicles. The weight problem can be partially solved by using chemical adhesives to secure a variety of components used in the transportation industry, thereby eliminating mechanical attachments or fasteners that may be employed. Additionally, mechanical supports that are used to hold windows in place may likewise be supplanted with the use of an adhesive system. Deck lids and hoods which require mechanical fastening techniques or costly supplementary aids such as welding can also be a place for the use of adhesives, thereby;decreasing the weight of the mechanical components. Deck lids and hoods which require dual mg/~

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methods to insure precise fit involve costly welding and unsatisfactory adhesive bondlng which result in high labor intensity due to clean up of equipment and parts and the buffing and polishing of par-ts to eliminate pinch weld marks. These are other advantages for adhesive useO
The theory of adhesives and ~he use of various adhesives are generally well known in the art~ For a background on adhesives, see the Handbook of Adhesive Bonding edited by Charles V. Eagle, published by McGraw Hill, Inc., in particular, Chapter 19. See also ~pplied Polymer Science edited by J. Kenneth Craver and Roy WO Tess~ published by the American Chemical Society, 1975, pages 473 and follo~ing, for a recitation of well known adhesivesO
Sum_ary of the Invention __ It is an object of the present invention to provi.de a novel adheslve assembly~ It i.s also an object o the p.resent invention to provide a novel process for secur.ing a plurality of subs~rates to each other, particu:Larly when the substrates are dissimilar materials.
The invention i.s concerned with an adhesive assembly comprising- a3 a first adhesive selected from the group consisting of epoxide, urethane, polyester, alkyd, polythiol, silicone, e].astomeric rubber, anaerobic, polysulfide, acrylic, cyano acrylatet acetate, cellulosic, polyamide and phenolic, b) a second adhesive which is of a different chemical com-position than the first adhesive, and wherein the adhesive is encapsulated or is retained in bubbles of a plàstic film; and c) positioned between the first and second adhesives, a barrier means for preventing contamination of tne respective adhesives or the substrates to which they adhere~ wherein cb/ r ' the barrier means is also a carrier means for carrying the adhesives; and components a, b and c being an in-tegral assembly.
Basically, Applicant's invention relates to the design and u-tillzation of -the adhesive assemblv as a one package albeit integrated unit~
The present invention is also concerned with a method of adhering together a plurality of subs-tra-tes, especially -2a-c~ f.

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dissimilar substrates, utilizing the assembly described above comprising the steps of:
l. applying the first adhesive to a first substrate;

2. applying a second adhesive to a second substra-te;
5 and

3. positioning a solid flexible resilient barrier means between the first and second adhesive thereby pre-venting contamination between the respective adhesives or the substra-tes to which they adhere.

lO Brief _ c iption of Drawings Fig. l is a perspective view of the adhesive asse~bly of the present invention;
Fig. 2 is an alternative embodiment of the adhesive assembly of the present invention by employing the assembly 15 of Fi~. l with removable backing;
Fig. 3 is a side perspective view showing the adhesive assembly of the present invention adhering a side body molding to a vehicle, such as the vehicle door;
Fig 4 is a diagr~nmatic par-t section, part elcvation 20 view of one embodiment of the adhesive assembly;
Fig. 5 is a diayramma-tic part section, part elevation view of an alternative adhesive assembly construction of the present invention.
Fig. 6 is a diagrammatic part section, part elevation 25 view of an alternative embodiment oE the adhesive assembly construction of the present invention.
Fig. 7 is a diagrammatic part section part elevation view of an alternative embodiment of the adhesive assembly construction of the present invention.
Fig. 8 is a diagrammatic part, sectional part of an alternative embodiment of the adhesive assembly construction of the present invention.
Fig. 9 is a diagrammatic part, sectional part of an alternative embodiment of the adhesive assembly construction 35 of the present invention with removable backing.
Fig. 10 is a side perspective view of a side body molding with the adhesive assembly construction attached thereto further containing a removable covering.
Fig. ll is a deck lid employing the adhesive assembly 40 of the present invention.
Fig. 12 is a sectional view of Fig. 11 taken along llne 12-12.

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~;g. 13 is a sectional view of the window assembly in a vehicle employing the adhesive assembly construction of the present invention.

Description of Preferred Embodiments The adhesive assembly of the present inven-tion employs any adhesive that can be secured to the barrier means. The adhesive assembly of the prcsent invention will be used to secure a plurality of substrates together.
In order to have satisfactory adhesion, the adhesive can 10 be designed to adhere to the particular substrate that is contemplated. In this manner, the adhesives tha-t are employed on both sides of the baxrier means would be different in their characteristics. By "different" is meant that the adhesives will be of dissimilar chemical 15 construction or be comprised of dissimilar chemical components or the adhesives will have dissimilar holding strengths so that it can be said that the adhesives are not of substantially the same identical components. By "holding strength" is meant shear adhesion oE the adhesive 20 in the adhesive assembly.
The barrier means useful in the present invention is generally one that is impervio~s to the components of the adhesives. ~he barrier means, likewise, should be impervious to the migration of the components of a ~5 substrate to which the adhesives are applied. As has been described, the presently employed side body moldings contain plasticizers in the polyvinyl chloride side body molding. During the adhesion of the side body molding to the door of a vehicle, the plastici~er tends to degrade 30 the adhesive, thereby preventing the adhesive from operating and functioning properly. The present invention employs a barrier means which can prevent the components of the polyvinyl chloride from passing through, or coming into contact with, the adhesive which is securing the side 35 body molding to the wall of the vehicle.
The barrier means can also be considered a carrier means for carrying the first and second adhesives. Suit-able barrier means vary with the adhesives employed but may be paper, a metallic layer, such as iron, steel, 40 aluminum, titanium, magnesium and alloys thereof, and the like, synthetic organic plastics, such as polyvinyl chloride, polyethylene nylon, polypropylene, polyester .. ~;f~. ' ' ' , .~ ,,.3, .

', "` ' film, such as Mylar (trademark of DuPont), and the like.
It is to be appreciatcd that the barrier means may be of any construction sufficient to carry the adhesives. Such a construction may require that the barrier means be 5 flexible, resilient and in some cases non-flexible and have sufficient strength and have a coefficient of expansion similar to the substrate to which it will be attached, such as metal or plastics. ~dditionally, -the barrier means may be corrugatea along its lon~itudinal 10 length in order to maintain its confi~uration a:Eter long term usage to prevent shriveling, shrinkincl or curling up at the end of the construction that it is employed, such as in a side body molding.
The barrier system must be designed with the 15 particular adhesives that are to be employed. For e~ample, if an anaerobic adhesive is used, it is known that expulsion of air is required. In such instance, the barrier means should be constructed such that the side that faces the anaerobic adhesive could be manipulated 20 durin~ the application of the adhesive to the substrate so that the air can be expelled from the area between the substrate, the barrier means and the anaerobic adhesive.
The substrates to which the adhesives will be applied vary ~uite broadly. ~hey could be metallic 25 substrates, such as aluminum, zinc, iron, s-teel, titanium, magnesium and alloys thereof, and the like, wood, glass, synthetic organic plastics, such as acrylics, acetates, cellulose, acetal, polycarbonates, polyolefins, such as polyethylene, polypropylene and the like, phenylene oxide, 30 polyamide, such as nylon and the like, polystyrene, poly-vinyl alcohol, polyvinyl acetate, polyurethanes, poly-sulfones, polyesters, such as polyethylene -tetraphthalate, and linear polyesters, such as Mylar (trademark of DuPont for a polyester film) and the like, fluorocarbons, such 35 as polytetrafluoroethylene, polyfluoroethylene (FEP), polychlorotrifluoroethylene, polymonochlorotrifluoro-ethylene such as KEL-F (trademark of DuPont for fluoro-carbon products including polymers of chlorotrifluoro-ethylene), polyvinyl fluoride and the like, amino 40 plastics, such as those based upon urea and/or melamine and derivatives thereof, and the like, polyethers, phenoxies, phenolics, especially those aerived from bisphenol-A reacted with epichlorohydrin and the like, ~'~` .
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diallyl phthalate silicones, epo~ides, ionomers such as Surlyn ttrademark of DuPont) anq the like, alkyds, polyallomers and laminates thereof, and the like. In addition, the substrate could be a rubber substrate, a felt substrate which may be based on cellulosic materials and the like, and other similar materialsO For a listing of suitable plastics, reference may be made to 1975-1976 Modern Plastics Encyclopedia for a recitation of resins, films and -the like. It is to be appreciated that any of the aforemen-tioned substrates may be painted with the usual primers and top coats employedt such as syn-thetic organic chemical resins that are lacquers, enamels, non aqueous dispersions, wa-ter soluble and water borne paints, powder coa-tings and the like.
The adhesives can be formulated in known means depending upon the variety and type oE adhesives that are to be employed. A way that is of signif~cant interest is the microencapsulation technique. See "Advances In Microencapsulation Techniques", Flinn et al, Battelle Technical Review, 19670 The encapsulation technique can be prepared by known coacervation method such as that taught in U.S. 2,800,457 and 2,800,458. In addition, dual walled microcapsules can also be employed as a technique for conta:ining the adhesive. See U.S. ~,076~7~.
A variety oE means of encapsulating adhesivos are well known in the art. U.S. Patent 3,825,640 indicates that capsules can be manufactured in accordance with the techniques of interFacial poly-merization (U.S. 3,~32,327) or phase separation (U.S. 3,~15,758;
U.S. 2,800,457) or solvent exchange (U.S. 3,516,943) or meltable dispersion (U.S. 3,161,602) or mechanical methods of film impingement (U.S. 3,015,128) or spray drying (U.S. 3,016,308). A variety of classes of adhesives may be encapsulated. Some of the more familiar materials are epoxides, urethanes, unsaturated polyesters, alkyds and other resins. Liquid adhesive, such as a polythiol with an encapsulated curing agent, may be prepared thereby having a one part system such as that taught in U.S. 3,748,313O This technique is applicable not just to polythiol adhesives but to virtually any adhesive which requires the use of a curative, for the cura-tive may be encapsulated and the capsule broken during the desired curing thereof. Encapsulated techniques are also taught in Chemical Engineering, December 4, 1967, at about page 177. The technique of containing an encapsulated curing catalyst for polysulfides is also taught in U.S. 3,505,254.

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A particularly advantageous -technique would be -to apply a coating to the encapsulated adhesives so -that they may then be applied as a normal coatin~ composi-tion somewhat similar to a liquid paint, thereby allowing the substrate -to have the composition attached thereto, wherein the substra-te is the barrier means described above. U.S~
3,694,243 has a meltable adhesive clinging in a dust-li]ce fashion about encapsulated adhesives, thereby permit-ting a variety oE adhesives to be employed. The wall surrounding the adhesives would be a gelatin or a gum arabic.
One could encapsulate epoxies, polyesters, silicones, polysulfides or polyurethanes by the techni~ue taught in U.S. 3,725,501, wherein multiple adhesives with separa-te curing agents for each were encapsulated in separate compartments so that there would be one package for the material.
If one wished to have elastomeric adhesive, U.S. 3,813,259 teaches a resin coated encapsulated elastomeric crumbs which contain various rubber materials.
A particularly preferred technique is the utilization oE
encapsulated anaerobic adhesives. Means for encapsulating said anaerobic adhesives are taught in U.S. 3,814,156; 3,826,673; and 3,826,756. A pressure`sensitive anaerobic adheslve composition :Ls taught in U.S. 3,996,308, wherein the accelerator therefor is encapsulated.
It has been Eound particularly advantageous to have a means for releasing anaerobic adhesives after they have been cured as a safety mechanism. The releasing means is in direct contact with a por-tion of the barrier means, to which the anaerobic adhesive is attached.
Basically, the releasing means is a collection of microencapsulated organic solvent, which solvent has the capability of dissolving the cured anaerobic adhesive. Utiliza-tion of such an encapsulated solvent allows a release of the anaerobic adhesive because the solvent will dissolve the anaerobic composition which is generally acrylate in ma/~ _ 7 _ '7~

nature. Formation of the encapsulated adhesive can occur through any of the appropriate techniques Xnown in the art.
See Chemical Engineering, supra. The application of an encapsulated anaerobic adhesive therefore must be such 5 that the encapsulated releasing means, describecl above, is not ruptured prior to the curing of the adhesive. This can be accomplished by having the releasing capsules located on a particular longitudinal portion of the barrier means but juxtaposed to -the cured anaerobic adhesive.
Any well known organic splvent useful for dissolving acrylic materials can be employed, such as aromatic solvents such as benzene, toluene, xylene and the like, alkyl ethers, ethylene, propylene, diethylene, dipropyle~e, triethylene, tri~ropylene glycol and the acetate derivatives thereof, such as the Cellosolve or Carbitol solvents ~trademarks of Union Carbide).
The adhesives may also be secured to the barrier by means of plastic bubbles containing the aahesives. Such techniques are will known in the art. See, for example, 20 U.S. 3,677,974, A particularly advantageous technique is to employ a plurality of different adhesives as the Eirst ad]lesive.
Additionally, one could use a plurality of adhe~ives as the second adhesive. This technique can be fulfilled by 25 encapsulating the different adhesives and securing them on one side of the barrier means. Alternatively, multiple types of adhesives could be on both sides of the barrier means, providing the adhesives are "different" as described above.
It is to be appreciated that by the encapsulation technique or by the technique of retaining the adhesive within plastic bubbles, one could use multi-component adhesives. This is the technique that may frequently be employed with polyurethanes or epoxy materials where the 35 cross-linking agent or the curing agent employed is separate from the primary portion of the adhesive system which is the binder. Anaerobic adhesives could also be employed in the present application, especially micro-encapsulated anaerobic adhesives where the various - 40 components of the anaerobic system are present in a number of plastic bubbles ox capsules. For example, the anaerobic cornposition which is the polymerizable monomer may be in one plastic bubble with the other plastic b~bles cont~inin~ -the polymerization inhi.bitor, a polymerl~ation initiator, a polymerization acceL~rator, and a pla~ticizer and the like.
Due to the increased desire in having lighter weiyllt 5 transporta-tion vehicles, significant emphàsis is being placed upon synthetic organic plastics o.r compositions to replace metallic components, such as steel o:r zinc die castings, in the vehicle. Because of thls, .~pplicant has found it desi.rable to employ the adhesive assembly of the 10 present invention. Therefore, listed below are a variety of adhesives that may be employed wi-th the particu].ar plastic substrates to which the adhesive is -to be applied.
Applicant directs attention to the Handbook of Adhesive Bonding, supra A variety of plastic substrates are 15 described below for the adhesive assembly of the present invention.
If one wanted to adhere a substrate to a second substra-te which is comprised of an acrylic ma-terial, one coula employ as the second adhesive a polysulfide, a po:Ly-20 urethane, an acrylic based adhesive, an epoxy, or for aquick set the use of a polycyano acrylate or other anaerobic compositions.
If one wanted to adhere one suostrate to a second substrate co~prised of an acetate, cellulose, an acetal, 25 one could employ as the second adhesive an aceta-te, a cellulosic composition, a polysulfide, a polycyano acrylate or rubber based polymer.
If one wished to apply a substrate to a second substrate comprised of polycarbonate, one could employ as 30 the second adhesive a solvent cementing technique, that is, use a plastic in a solvent, for example, methylene chloride, which contains a polycarbonate, such as Lexan ~trademark of GE for a polycarbonate), or one may use a silane primer together with the appropriate adhesive.
If one wished to apply a substrate to a second substrate comprised of a polyolefin, such as polyethylene, polypropylene and the like, one could employ a heat sealed technique where the second adhesive could be a polyester, a polyamide, an epoxy, a nitrile phenolic, an 40 epoxy phenolic, a polysulfide epoxy, a polyurethane or other hot melt adhesives or a polyester (U.~. 3,620,~02).
If one wished to adhere a rirst substrate to a second substrate comprised of polypropylene, one could use as the second adhesive an epoxy, a polyamide, a .. ,~ ,~. . .

polysulfide epoxy, a nitrile phcnolic, a polyurethane or a hot melt adhesive.
If one wished to adhere a irst substrate to a second substrate comprised of phenylene oxide, one could 5 use as tile second adhcsive an epoxy, a ni-trile phenolic, or a polyurethane.
If one wished to adhere a first substrate to a second substrate comprised of a polyamide, such as nylon, one could employ as the second adhesive an epoxy, a 10 nitrile phenolic, a nitrile rubber, neoprene or a urethane and the like.
If one wished to adhere a first substrate to a second substrate comprised of polystyrene, one could employ as a second adhesive a polysulfide, a Versamide 15 (trademark of General Mills Chemical, Inc. for thermo-plastic and reactive polyamide resins) epoxy, or a poly-urethane.
If one wished to adhere a first substra-te to a second substrate comprised of polyvinyl alcohol, polyvinyl 20 fluoride, acetates or polyvinyl chloride, one could use a second adhesive such as nitrile rubber based adhesive, neoprene, epoxies, polyurethanes and the like. In addition, polyvinyl alcohol could be cemented with water and glycerin.
If one wished to adhere a first substrate to a 25 second substrate comprised of a polyurethane, one could use a second adhesive based upon a polyurethane elastomeric type, an epoxy, a foam which could be bonded with a poly-sulfide, an epoxy, a polyurethane, a nitrile-neoprene and the like.
IE one wished to adhere a first substrate to a second substrate comprised of a polysulfone, one could employ a second aahesive such as an epoxy, a polyurethane and the like.
If one wished to adhere a first substrate to a 35 second substrate comprised of a polyester such as a poly-ethylene tetraphthalate or a linear polyester such as Mylar~ one could use a second adhesive such as an epoxy, a urethane, or other elastomeric type systems.
If one wished to bind a first substrate to a second 40 suostrate comprised of fluorocarbons, such as pol~tetra-fluoroethylene (PTFE), polyfluoroethylene (FEP), poly-chlorotrifluoroethylene, polyvinyl fluoride, polymono-chlorotrifluoroethylene, such as KE~-F~ one can use a .

variety of second adhesives, although -th~ bon~ing strengths are not particularly high.
If one wished to bind a first subs-trate to a second substrate comprised of amino plastics, such as urea or 5 melamine based coinpositions, one could use the second adhcsive of epoxy or a po]yurothane and the like.
If one wished to bind a first substrate to a second substrate comprised of a polyether, one could use as a seaond adhesive an epoxy or polyure-thane.
If one wished to bind a first substrate to a second substrate comprised of a phenoxide, it should be appreciated that it is difficult -to adhere to the substrates; however, by employing a pre-sensitizing technique, one may employ elastomeric systems or urethane epoxies as appropriate 15 secona adhesives.
If one wished to adhere a first substrate to a second substrate, where the second substrate is comprised of a phenolic resin, one may employ second adhesives such as epoxies, epoxy phenolics, nitrile phenolics, or polyamides 20 and the like.
If one wished to bind a first substrate to a second substrate comprised of a dial].yl phthalate, one could employ a second adhosive such as an epoxyl polysulEide, furanes, polyester styrenes, polyurethane, and the 25 utilization of primers may enhance the adhesion.
If one wished to adhere a first substra-te to a second substrate comprised of silicone, one could use as a second adhesive a silicone adhesive plus a primer.
If one wished to adhere a first substrate to a second 30 substrate comprised of an epoxy, epoxide or any epoxy fiberglass filled material, one could use as a second aahesive an epoxy, nitrile phenolic, an epoxy polyurethane or vinyl phenolic.
If one wished to bind a first substrate to a second 35 substrate comprised of polyester and laminates thereof, one could use as a second adhesive epoxies, phenolics or polyesters.
I one wished to bind a first substrate to a sccond substrate comprised of ionomers, such as Surlyn ttrademark 40 of DuPont for ionomer resins), one would employ.as a second adhesive an epoxy or polyurethane.
If one wished -to bind a first substrate to a second substrate comprised of an alkyd, one wou~a employ as a second adhesive an epoxy, nitrile, neoprene os polyurethane.

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If one wished to adhere a flrst substrate to a second substrate comprised of a polyallomer, such as a polyallomer copolymer of propylene and ethylene, one could employ second adhesives which are similar to the adhesives fox 5 polyethylene and polypropylene.
It is to be appreciated that the adhesives that have been described above are well known in the art and can be formulated from well known techniques. See, for example, the following:
U.S. 3,639,137 teaches a metal fastener coated wi-th a pressure-activatable encapsulated sealant system where the substra~e has a curing agent attached thereto on top of which is a pressure-rupturable capsule that has a sealant therein. The sealant that is employed is primarily 15 an adhesive of the liquid polysulfide type con-taining a corrosion resistant compound therein. The fastening system that is described is generally of the threaded bolt or rivet type system.
U.S. 2,907,682 teaches an adhesive type tape 20 containing pressure-rupturable capsules with adhesives of two dissimilar types. Similarly, is U.S. 2,988,460 which teaches microscopic pressure-fracturable capsules which is a heat sensitive material, tha-t is, that -the fractured capsules will not release -the adhesive until 25 heated above 100F. In a similar fashion, see U.S.
2,9~8,461 which teaches similar capsules containing chlorinated rubber and phthalates and chlorinated diphenyl.
U.S. 2,986,477 is guite similar to the -460 and -461 patents except that it teaches a tacky adhesive 30 comprised of isobutylene polymer.
U.S. 3,663,269 teaches a wall covering that has a coating of dry encapsulated adhesive which is a heat-activatable adhesive of the acetate acrylic type.
U.S. 3,565,247 teaches a pressure-sensitive adhesive 35 tape containing a multiplicity of microscopic closed cells which is formed by a blowing agent thereby foaming the adhesive. The technique is useful in a fabrication of aircraft skins from individual aluminum panels, enabling the manufacturer to insure that pressure will be maintained 40 in the cabins of the planes traveling at high altitudes.
U.S. 3,578,482 relates to the screen coating of a profusion of pressure-rupturable capsules whose walls are elastic and readily distorted during their coating through ~S .~.

a screen onto a substrate, bu-t which are subsc~uently hardened while on the substrate itself.
U.S. ~,039,705 teaches an anaerobic pressure-sensitive adhesive stock, such as sheets and self-wound 5 tapes, from which an adhesive layer includlng an anacrobic resin system can be completely transferred to one substrate to be bonded to another and cured upon the exclusion of oxygen. The patent teaches at Column 3, Line 20 and ollowing, tha-t if the anaerobic pressure-sensitive 10 adhesive system contains free transition metal ions, then at least the peroxy initiator may be encapsulated in microspheres which, upon rupture and upon the exclusion of oxygen, will initiate cure.
U.S. 2,800,457 in general teaches the preparation of 15 oil-containing microscopic capsules of complex hydrophilic colloid material and to a method of making them by coacervation.
U.S. 2,785,083 relates to a method of applying an adhesive to sheet material wherein the adhesive is a 20 silicate glass solution which is applied -to cellulosic surface materials. The technique is par-ticularly advantageous to the application of the invention in the manufacture of plywood.
U.S. 3,592,722 teaches a slidable adhesive laminate 25 which contains a pressure sensitive adhesive layer, a layer of vinyl filml a layer of release material covering the exposed surface of the adhesive layer and a backing sheet. As pressure is applied, the release dots are fractured so that the adhesive makes contact wi~h the 30 surface, U.S. 3,750r728 teaches the use of pressure sensitive adhesive strips in wood millwork wherein the adhesive is a hot melt adhesive or a pressure sensitive adhesive.
U.S. 3,808,088 relates to a spray process for the 35 deposition of spots of adhesive latexes containing carboxylic. The spots are discrete droplets of the adhesive material which is sprayed onto the substrate.
U.S. 3,813,279 tcaches elastic foam carpet underlay which is encapsulated within a plastic bubble which is a thin flexible impervious sheet of polyethylene, also having a thin l~yer of saran so that hermetically sealed would be foam rubber in a certain amount of water.

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U.S. 3,908,052 teaches liquid crystal display devices which are sealed in polyethylene ma-terials.
Turning now to a dcscription of the drawings, Fig. 1 shows the adhesive assembly 20 of the present invention 5 having a first adhesive 22 and a second adhesive 24 separated by the barrier means 26. Because the invention is concerned with a double-backed adhesive, Fig. 2 shows that the adhesive assembly can havc removable layers 28 and 30 on both sides o the adhcsive assembly. The 10 removable layer generally is in a peelable type ma-terial, such as paper, thin plastic film or coating, such as polyethylene, polypropylene, a nylon, Mylar~and the like.
The invention is concerned with a variety of ways of retaining the adhesives on the opposite sides of the 15 impervious barrier. FigO 4 shows a liquid adhesive 32, which i5 the first adhesive, and the second adhesive 34 being on the opposite side of the impervious barrier 26.
The adhesives are encapsulated within Eilm coat 36 and 36' for the first and second adhesive means respectively.
20 Alternatively, the fil~ coat could be an encapsulation technique where particulate materials in the area oE .01 microns to 100 microns are encapsulated in a known technique as described above or in a double-walled microcapsule as described in U.S. 4,076,774 or in plastic 25 embodiments as described abvve. The key point, however, is that due to the particular nature of the adhesive a variety of means for holding the adhesive on opposite sides of the barrier means may be used. For example, Fig. 4 shows that the adhesive or any of its consti-tuent 30 componen-ts are in the liquid state as contrasted with Fig. 5 where the adhesive 38 is in the solid state but incorporated within the film 36 and 36'.
Fig. 6 is a preferred embodiment that relates to the adhesive assembly of the present invention wherein an 35 anaerobic adhesive 32 which is in the liquid state is retained in a microencapsulated form by means of film 36 or by means of the plastic bubbles as described above.
The impervious barrier separates the second adhesive which is preferably in this embodiment as a spongy adhesive mass.
40 In general, utilizing the adhesive assembly of Fi~. 6, a curing agent would be applied to the substrate and then the anaerobic adhesive 32 of Fig. 6 would be pressed againsk the substrate~ In this process, the bubbles or r~

the capsules would be burst, the air would be expelled between the impervious barrier and the metal subst~ate and the ana~robic composition would be cured.
The spongy surface 24 of Fig. 6 is on the backside 5 of the impervious barrier. The spongy material could be a pressure sensitive adhesive, generally within about 1 to about 10 mils in thic~ness, preferably 3 to 5 mils in thickness. Suitable sponyy Jnasses would be a neoprcne sponge adhesive, a polyethylene sponge adhesive, a 10 urethane sponge adhesive and the like.
It should be appreciated that any and all oE the adhesives described above may employ other components therein to make them stable to the environment and to ultraviolet light and may also contain other desirable 15 components, such as dyes, colorants, pigments and the like. It is well known to add W stabilizers and anti-oxidants to stabilize the adhesive mass.
The adhesive assembly of Fig. 7 is very similar to the adhesive assembly of Fig. 6 except that the adhesive 32 20 may be of a solid type and that the pressure sensitive adhesive mass 24 may contain as a protective covering 30 a roll or sheet of paper as described above.
The adhesive àssem~ly described in Figs. 6 and 7 can be used in those situations requiring a quick bonding 25 of a relatively stiff item such as an au-tomo-tive name plate to a surface to which it fits poorly. To effect the close fit required, it is proposed that the double-coated barrier tape shown in Figs. 6 and 7 with the adhesive on the name plate side of the barrier be of a thick spongy 30 adhesive nature itself or consist of a foam elastomeric spongy mass with an adhesive coating, while the o-ther side of the barrier contains or carries the anaerobic adhesive applied just before making the bond or applied in the form of a microencapsulated adhesive as described 35 above. Upon asse~bly by pressing on the name plate usually by a fixture or a mechanical roller, a close fit between the anaerobic coated barrier sheet and the adhering surface is assured with the inequalities taken up by the spongy mass between the other side of the barrier sheet and the name plate. The mechanical pressing breaks up the encapsulation of the adhesive present with the close it obtained excluding the air and assuring curing of the anaerobic adhesive.

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~ nother alternative is that shown in Fig. 7 wherein the anaerobic adllesive could be the first adhesive 32 enclosed within the plastic bubbles or microencapsulated within particulate substances as described above.
5 Attached to the anaerobic adhesive would be the inert impervious barrier 26 which in turn is attached to a spongy foam or other type layer to which is attached the second adhesive 24. This spongy layer 25 is introduced at this point in order to facilitate handling character-10 is-tics of the substrate. This type of adhesive assembly allows sufficient "give" as the adhesive assembly is being applied to the desired substrate.
Turning to Fig. 8, there are a variety of adhesive configurations that could be employed. Fig. 8 shows tha-t 15 on bo-th sides of the impervious barrier 26 is a spongy layerO The top layer 22 in -this case can be a silicone or urethane adhesive caulk. Such silicone adhesives may be obtained from Dow Corning or other suppliers. Attached to the impervious barrier could be a foam or spongy layer 20 to which is attached the adhesive 24. The foam or spongy layer can be prepared in a well known manner. In the configuration shown in Fig. 8, the impervious barrier 26 may act more as a carrier because of the nature of silicon adhesives. The barrier can also act as an ultraviolet 25 barrier to prevent the degradation of the silicon sealant.
Frequently, the composition such as that shown in Fiq. 8 may be used to adhere glass windows to a metallic substrate on one side ana a plastic substrate on the other side. It is to be appreciated -that the adhesives as 30 described above could be used depending upon the plastic substrate one wishes to adhere a second substrate thereto.
For example, one may wish to have a fiberglass reinforced polyester substrate adhered to glass. This may be accomplished by employing an epoxy cement or sealant or 35 adhesive on one side and have the silicone adhesive on the other side. It should be kept in mind that a spongy layer such as that shown in Fig. 8 would be desirable in order to impart flexibility to a glass assembly preventing building up of high stresses due to differences in 40 coefficient of expansion when the assembly is subjected to cold temperatures. Fig. 9 shows the adhesive assembly of Fig. 8 except containing peelable backing 28 and 30, such as paper.

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~17-It is to bc appreciated that the adhesive assembly of the présent invention disclosed in Figs. 1 and 2 may be sold as a unit. Alternativcly~ they may be sold to manufacturers of side body moldings. In this situation, 5 Figs. 3 and lO show that the side body molding 40 is comprised of poLyvinyl chloride or other type materials such as Surlyn~or polyester 42 encased within a metal extrusion 44 having a ~.ylar~coating (not shown). See U.S. 3,745,056. The PVC 42 is adhered to first adhesive 10 member 22 to which is attached the impervious barrier 26 and to which is attached the second adhesive layer 24.
Again, a plas-tic or paper roll or covering 30 would be attached to the second adhesive 24 in order to make the side body molding handleable. After the paper covering 30 15 is removed from the side body molding of Fig. 10, it is then applied as best shown in Fig. 3 where the adhesive assembly 20 is shown in perspective as it is about to be attached to the automotive door 46. Adhesive 24 could be any adhesive that preferably binds or adheres to metal 20 which ls the door substrate, while adhesive 22 would preerably be one that adheres best to a ~VC or other type plastic of which the side body molding 40 is comprised.
~ deck lid 50 is shown in Figs, 11 and 12 comprising 25 a top member 52 and a bottom member 54 secured by mcans oE
the adhesive assembly 20 best shown in Fig. 12. It has been found that the top and bottom members of the deck lid are comprised of dissimilar materials and, therefore, it is highly desirable that the first adhesive 22 in 30 adhesive assembly 20 be one that adheres best to the upper deck lid component 52, while the second adhesive 2g would be one that preferentially binds with the metallic portion 54. In a similar fashion, a multi-component hood could be assembled with desirable adhesives.
Fig. 13 is a window assembly 60 which is comprised of a roof member 62 to which is attached a top support 64 and a bottom support member 66. The window 68 is fixedly retained within the upper and lower sections 64 and 66 respectively. The upper member 64 has a synthetic plastic 40 member 70 used to retain the window in position. The adhesive assembly 20 is inserted between the plastic member 70 and the glass 68. In the insertion of the glass in the lower member 66, the adhesive assembly is used as ~ .
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follows: ~ strip of adhesive assembly is appl:ied to a glass frame 68 so tha-t it engages the periphery oE the qlass Erame in a U-shaped capaci-ty. Inserting the glass into the window assembly, -the adhesive assembly 20 is also placed along the periphery of -the -top portion of the glass. From the inside of the vehicle the glass is then inserted into the U-shaped portion 72 of the lower member 68 thereby retaining the glass in the recep-tacle and the top portion is then snapped into position using adhesive assembly 20 coming into contact wi-th the plastic member 70.
It, therefore, can be seen that the adhesive tha-t is used to secure the plastic could be one type of adhesive, such as the adhesives described above depending upon the plastic, while the other side of the adhesive assembly would contain an adhesive that would preferably adhere to the glass and have high tensile sheer strength, such as a silicone adhesive, with or without a spongy foam layer as described above, or other type adhesives. Additionally, the adhe.sive that may be used to retain the glass could be a butyl rubher tape such as that is made commercially available by PPG. The tape is soft enough to easily deform when glass is pressed into place, and it accommocla-tes ~0 the poor fit between g`Lass surface and a sheet metal. For higher strength, a po:LysulEide rubber adhesive may be employed such as that sold by Thikol Corpora-tion. It has been found desirable tha-t an amino silane ~manufactured by Goodrich or ~nion Carbide) wiped onto the glass surface would assure maximum adhesion to the glass prior to the application of the polysulfide rubber.
Alternatively, a high streng-th urethane caulk may be used.
The material is a one component caulk which is extruded onto the primer coated glass and cures by absorption of moisture from the airO A
glass primer is used with the adhesive urethane caulk, which is an aliphatic urethane containing suitable pigments and antioxidants to give good resistance to ultraviolet rays from the sunO Other adhesives such as epoxies could also be used to adhere the glass, but reasonable softness is needed to prevent locali~ed overloading and breakage of the glass due to impact or s-tresses induced by differences in coefficient of expansion between the Eilled epoxy and the glass and the body steel.

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'l'h-ree classes of adhes:ive asserllblies are c3eneral:Ly considered desirable:
1. The firs-t adhesive is comprised of an anaerobic adhesive (preferahly retained in bubhles of a plas-tic film or encapsula-ted) and the second adhesive is comprised oE a spongy adhesive mass;
2. The first adhesive is comprised oF an anaerobic adhesive (preferably retained in bubbles of a plas-tic film or encapsulated) and the second adhesive is comprised of a foam or spongy layer wi-th an adhesive layer atop the spongy layer; and 3. The first aclhesive is comprised oE a silicone or urethane adhesive and the second adhesive is corrlpr~sed oE a foam or spongy layer wi-th an adhesive layer atop t:he spongy layer.

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Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. An adhesive assembly comprising:
a) a first adhesive selected from the group consisting of epoxide, urethane, polyester, alkyd, polythiol, silicone, elastomeric rubber, anaerobic, polysulfide, acrylic, cyano acrylate, acetate, cellulosic, polyamide and phenolic;
b) a second adhesive which is of a different chemical composition than the first adhesive, and wherein the adhesive is encapsulated or is retained in bubbles of a plastic film; and c) positioned between said first and second adhesives, a barrier means for preventing contamination of the respective adhesives or the substrates to which they adhere,wherein said barrier means is also a carrier means for carrying said adhesives, and components a, b and c being an integral. assembly.

2. The assembly of claim 1 wherein the first adhesive is comprised of an anaerobic adhesive which is encapsulated or is retained in bubbles of a plastic film.

3. The assembly of claim 1 wherein the first adhesive is adhering to a first substrate and the second adhesive is adhering to a side body molding.

4. The assembly of claim 1 wherein the first adhesive is adhering to glass and the second adhesive is adhering to a plastic support for said glass.

5. The assembly of claim 1 wherein the first adhesive is adhering to glass and the second adhesive is adhering to a metallic support for said glass.

6. The assembly of claim 1 wherein the first adhesive is comprised of two chemically dissimilar adhesives.

7. The assembly of claim 2 wherein the first adhesive is comprised of an anaerobic adhesive and the second adhesive is comprised of a spongy adhesive mass.

8. The assembly of claim 2 wherein the first adhesive is comprised of an anaerobic adhesive and the second adhesive is comprised of a foam or spongy layer with an adhesive layer atop said spongy layer.

9. The assembly of claim 1 wherein the first adhesive is comprised of a silicone or urethane adhesive and the second adhesive is comprised of a foam or spongy layer with an adhesive layer atop said spongy layer.

10. A method of adhering together a plurality of substrates by employing the adhesive assembly of claim 1 comprising the steps of:

1. applying the first adhesive to a first substrate;
2. applying he second adhesive to a second substrate; and 3. positioning a solid flexible resilient barrier means between the first and second adhesives thereby preventing contamination between the respective adhesives or the substrates to which they adhere.

11. The method of claim 10 wherein the first adhesive is comprised of an anaerobic adhesive which is encapsulated or is retained in bubbles of a plastic film.

12. The method of claim 10 wherein the first adhesive is encapsulated.

13. The method of claim 10 wherein the first adhesive is retained in bubbles of a plastic film.

14. The method of claim 10 wherein the first substrate is a side body molding.

15. The method of claim 10 wherein the first substrate is glass and the second substrate is a plastic support for said glass.

16. The method of claim 10 wherein the first substrate is glass and the second substrate is a metallic support for said glass.

17. The method of claim 10 wherein the substrates are dissimilar.

18. The method of claim 10 wherein the first adhesive is comprised of dissimilar adhesives,