Polycyanoacrylate Foam

V! 3\ is I561 PCT WORLD INTELLECTUALPROPERTY ORGANIZATION International Bureau INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT) WO 92/09651 11 June 1992 (1l.06.92) (51) International Patent Classification 5 : C08J 9/14 // , A6lL 15/12 C08L 35 :04 (11) International Publication Number: (43) Intemational Publication Date: PCT/GB91/02121 (74) Agents: COUCHMAN, Jonathan, Hugh et a1.; Hepworth Lawrence Bryer & Bizley, 36 Regent Place, Rugby, War- wickshire CV21 2PN (GB). (21) International Application Number: (22) Intemational Filing Date: 29 November 1991 (29.1 1.91) (81) Designated States: AT (European patent), AU, BE (Euro- pean patent), CA, CH (European patent), DE (Euro- pean patent), DK (European patent), ES (European pa- tent), FR (European patent), GB (European patent), GR (European patent), IT (European patent), JP, KR, LU (European patent), NL (European patent), SE (Euro- pean patent), US. (30) Priority data: 9026065.4 30 November 1990 (30.11.90) GB (71) Applicant (for all designated States except US): CHEM- ENCE LIMITED [GB/GB]; Princewood Road, Corby, Northamptonshire NNI7 7XD (GB). (72) Inventors; and (75) Inventors/Applicants (for US only) : COOKE, Bernard, Published Dominic, Noel [IE/ GB]; 11 Chase Farm, Wood Street, With international search report. Geddington, Northamptonshire NNI4 1RA (GB). KOT- Before the expiration of the time limit for amending the ZEV, Dimiter, Lubomirov [BG/ GB]; 21 Carron Close, claims and to be republished in the event of the receipt of Corby, Northamptonshire NNl7 2LB (GB). DICKIN- amendments. SON, James, Christopher [GB/GB]; 16 Burgess Court, Corby, Northamptonshire NNI8 OLX (GB). (54) Title: POLYCYANOACRYLATE FOAM (57) Abstract Polycyanoacrylate foam is made by mixing together a cyanoacrylate monomer, a liquid foaming agent and a polymerisa- tion initiator. The mixture simultaneously polymerises and foams. The foaming agent is usually an organic compound with a boil- ing point not higher than 100 °C, miscible with the monomer but not a solvent for the polymer. The monomer may be any 2-cya- noacrylate ester compatible with the composition. : FOR THE PURPOSES OF INFORMATION ONLY applications under the PCT.’ Austria Australia Barbados Belgium Burkina Faao Bulgaria Benin Brazil Canada AT AU I3 BE IF BC BJ BR Central African Republic Congo Switzerland Cote d‘lvoire Cameroon Ca:choslova£i.t Germany Denmark + Any desig any such designation ES FI FR GA GB GN GR HU IT JP KP Spain Finland France Gabon ,United Kingdom Guinea Greece Hungary Italy Japan Democratic People‘s Republic of Korea Republic of Korea Liechtenstein Sri lanka Luxembourg Monaco KR Ll LK LU MC 3»? Codes used to identify States party to the PCT on the front pages of pamphlets publishing international MG ML MN MR MW NL NO FL I10 SD SE SN SU " ‘I'D 'I'G US Madagascar Mali Mongolia Mauritania Malawi Netherlands Norway Poland Romania Sudan Sweden Senegal Soviet Union Chad Togo United States of America aim” nation of “SU” has effect in the Russian Federation. lt is not yet known whether has effect in other States of the former Soviet Union. nu W0 92/ 09651 l0 15 20 PC!"/GB9l/02121 .. 1 .. POLYCYANOACRYLATE FOAM This invention relates to a foam forming cyanoacrylate composition. Since their comercialization in the sixties adhesives based on cyanoacrylate monomers have found wide application. Numerous compositions are known in the art. A variety of additional components are introduced into the cyanoacrylate monomer to impart thickening (US Patent No. 2,794,788) and thixotropy (US Patent No. 4,533,422) of the adhesive, toughness (W0 83/02,450), heat resistance (Japanese _Patent No. 62,199,668), impact and peel-resistance (Japanese Patent No. 63,00,377), electroconductivity (W0 86/06,738) and other properties of the resultant adhesive bond. It has now been unexpectedly found that when cyanoacrylate monomers are mixed with organic liquids and polymerization initiators the so formed composition can transform itself by expansion into a simultaneous polymerization and polycyanoacrylate foam. based composition, comprising a cyanoacrylate monomer, a liquid foaming agent and a cyanoacrylate polymerization initiator. The present invention provides cyanoacrylate Upon or after formation of the composition it polymerizes to produce expanded polycyanoacrylate foam. The composition can also optionally contain other reactive monomers, as well as modifiers and additives such as polymeric thickeners, plasticizers, thixotropic agents, compatibilizers, pigments and colourants, fillers, deodorants and perfumes, for example. W0 92/ 09651 PCT I GB91 I 02121 _ 2 - In another aspect the invention provides a method of creating a polycyanoacrylate foam and the foam itself. The cyanoacrylate monomers used in the composition of the 5 invention are 2-cyanoacrylate esters of the formula CN 0 I ll CH2 = C - C - O - R 10 wherein R represents an ester-forming group. In principle, R can be any ester-forming group compatible with the monomer and with foam formation. For example, the group R should not initiate autopolymerization of the monomer or prevent 15 polymerization of the composition described above. R should also desirably be selected to provide a foam with the desired properties. Preferably R represents alkyl, alkenyl, alkynyl, aryl or an 20. aromatic heterocyclic radical. R may also be one of the foregoing moieties substituted with one or more other of the moieties; this includes the case of a substituent itself being substituted. Group R may contain other compatible substituents, for example alkoxy, alkoxyalkoxy, 25 carbalkoxyalkyl or halogen. In general, R can be any moiety which does not contain a sufficiently nucleophilic group to initiate polymerization or sufficiently electrophilic group to interfere with polymerization. The alkyl or alkenyl moiety may be cyclic and normally R contains from 1 to 16 30 carbon atoms and often.is a 1C, 2C, 3C, 4C, SC, SC, 7C or 8C group, more usually it is a lC—6C group. In the case of W0 92/0965] 10 15 20 25 30 T Specific PCT/GB91/02121 _ 3 _ moieties containing a heterocycle, heteroatom ring members are normally counted as a carbon atom. More preferably, R is alkyl, halogenated alkyl, alkenyl, alkynyl, phenyl, halogenated phenyl, phenylalkyl, halogenated phenylalkyl, alkoxyalkyl, alkoxyalkoxyalkyl, carbalkoxymethyl or alkylideneglyceryl, wherein the terms "alkyl" and include the corresponding cyclic Uninterrupted carbon chains preferably contain 1, "alkenyl" radicals. 2 or 3 carbon atoms. ethyl, Pent-Y1 I 3-chloropropyl, n'Pr°PY1: hexyl, examples of R are methyl, iso-propyl, n—butyl, iso-butyl, trifluoroethyl, 2-chloroethyl, 2-chlorobutyl, cyclohexyl, tertiary butylcyclohexyl, benzyl, phenyl, cresyl, allyl, crotyl, methallyl, propargyl, furfuryl, 2-methoxyethyl, 2-ethoxyethyl, 2-methoxyisopropyl, 2-(2'-ethoxy)-ethoxymethyl, 2—(2'—ethoxy)-ethoxyethyl, 2-(2'-ethoxy)-ethoxybutyl, methoxycarbonylmethyl, ethoxycarbonylmethyl, isopropoxycarbonylmethyl, isobutoxycarbonylmethyl, isoamyloxycarbonylmethyl and 1,2-isopropylideneglyceryl. Most iso-butyl, 2-methoxyethyl, preferred are ethyl, n—butyl, 2-ethoxyethyl and 2-methoxyisopropyl cyanoacrylates. If desired, a mixture of two or more cyanoacrylate monomers may be used. stabilized with anionic and free-radical polymerization inhibitors. Anionic polymerization inhibitors known in the art are soluble acidic gases (for example sulfur dioxide), hyrogen fluoride, sulfonic acids, Usually the cyanoacrylate monomers are phosphonic, carboxylic and organic WO 92/09651 10 15 20 25 30 _composition and its transformation PCT/GB9l/02121 - 4 _ and phosphazenes, for sultones, BF3 and its complexes example. The free-radical polymerization inhibitors are usually hydroquinone, p-methoxyphenol or t-butyl catechol, for example. The inhibitors are normally used in small amounts of from 0.00001 to 1% by’ weight of the monomer. The preferred quantities for the above-mentioned inhibitors are: gases - from 0.001% to 0.06%; acids — from 0.00052; to 0.01%; sultones - from 0.01% to 0.1%; BF3 - from 0.0001% to 0.01%; acidic 0.0001% to 0.001%; free-radical The foregoing percentages phosphazenes - from inhibitors — from 0.001% to 1%. are percentages by weight of the cyanoacrylate monomer. It should be noted that the quantity of inhibitor will influence the onset of polymerization of the composition of the present invention and could. be used as a means to control the time interval between the formation of the into a polymeric cyanoacrylate foam. The liquid foaming agent used in the composition of the present invention can be any organic compound with a boiling point. preferably not higher than 100°C. The liquid foaming agent used can be a single compound or a mixture thereof. Preferably it will be soluble or semi-soluble in the cyanoacrylate monomer and will not act asaa solvent for polycyanoacrylate. Preferably its Preferably it is a non-toxic, the corresponding solubility parameter should be below 9. non—polar liquid. Preferably it should be non—flammable and non-irritant. W0 92/ 09651 10 15 20 25 30 ‘used as liquid blowing agents. PCT/GB9l/02121 - 5 - Solubility parameter is a quantity used to predict the solubility of solutes and solvents and is explained in the "CRC Handbook of Chemistry and Physics", published by CRC Press Inc. of Boca Raton, Florida, USA see for example page C-676 of the 67th Edition (1986-87). The CRC Handbook also contains lists of solubility parameter values. Specific examples of foaming agents are pentane, hexane, heptane, 1,1,2-trichlorotriflouroethane, 1,1,1-trichlorotrifluoroethane, petroleum ether, diethyl ether, cyclopentane, cyclohexane, benzene, carbon tetrachloride, chloroform, methylcyclopentane, dimethylsulfide, 1,1-dichlororethane, 1,1,1-trichloroethane, perfluorohexane, perfluoroheptane, 1-bromopropane. Most preferred are pentane, hexane, 1,1,2-trichlorotriflouroethane, cyclohexane, petroleum ether and diethyl ether. The above—mentioned compounds are only representative and do not limit the compounds that can be It was found that even very polar liquids like ethanol and methanol or liquids which are typical solvents for polycyanoacrylates, like acetone, 2—butanone and acetonitrile, can be used as foaming agents. When solvents for polycyanoacrylates are used as foaming they expand the foam but immediately thereafter the foam shrinks in volume or sometimes Such are therefore normally unacceptable as foaming agents, collapses. solvents agents when used alone, but in principle can be used so long as the selected combination of solvent, polycyanoacrylate and their relative quantities do not lead to collapse of the foam. Polycyanoacrylate solvents are more acceptable when used in minor amounts with other foaming agents. W0 92/ 09651 10 15 20 25 30 'calixarenes, PCI‘/GB91/02121 - 5 - The volume ratio of cyanoacrylate monomer to foaming agent is not critical but is preferably from 1:10, to 20:1, more preferably from 1:2 to 5:1, especially from 1:1 to 4:1. The cyanoacrylate polymerization initiator used in the composition of the present invention may comprise any of the accelerators of the anionic The known initiators and polymerization of cyanoacrylate monomers, for example. anionic initiator can be used singly or in admixture with one or more other initiators. of anionic initiators are pyridine, methoxyethylpyridine, N,N-dimethyl-p-toluidine, N,N4dimethyl-m—toluidine, tribenzylamine, diethylenetriamine, poly(4-vinylpyridine), complexes, Specific examples aminopyridine, piperidine, picoline, N,N-dimethyl-o-toluidine, triphenylphosphine, triethylphosphine, triethylamine, benzyldimethylamine, benzyltriethylamine , tribenzylamine , tertiary amine-S03 vinylpyridine, lutidine, polyethyleneglycol, phenolformaldehyde triethanolaminatotitanium, N-(oxydiethylene) bismuth bases and Most initiators are N-(oxydiethylene) vinylimidazole, aminosilanes, phosphites, benzothiazole-2-sulfenamide, dimethyldithiocarbamate, as well as hydroxyl or amine group polymerization metal acetylacetonates, alcohols, containing compounds. preferred anionic N,N-dimethyl-p-toluidine and benzothiazole-2-sulfenamide. The above-mentioned compounds are only representative and do not restrict the scope of suitable initiators. For example any of the anionic polymerization initiators known in the resins,u W0 92/0965] 10 15 20 25 30 PCT/GB91/02121 art for cyanoacrylate monomers or accelerators of their anionic polymerization can successfully be used in the compositions of the present invention. Optionally, but not necessarily, free—radical polymerization initiators such as methylethylketone cyclohexane peroxide, cumene hydroperoxide or dibenzoyl peroxide, with the anionic polymerization peroxide, for example, can be used in conjunction initiator. In order to impart desired properties to the composition of the present invention and to the properties of the resultant further They can for economic considerations, foam, as well as additives can be introduced into the composition. be, for example, any of the known polymeric thickeners and viscosity regulators, rubbers, plasticizers and tougheners, compatibilizers, thioxtropic agents, colourants, deodorants or perfumes, for example, used in cyanoacrylate adhesives. ‘The composition may also contain other monomers containing a reactive double (di)methacry1ates, epoxy or urethane, in minor amounts, e.g. of the total monomer content and more preferably in an bond, for or reactive resins or oligomers, e.g. up to 25 mole % example (di)acrylates or amount of no more than 5 or 10 mole %. Upon mixing the three major components of the present invention foaming agent and initiator) a mixture (monomer, is formed in which, under the action of the anionic polymerization of the cyanoacrylate monomer which leads to the As a initiator, occurs. It is fast and exothermic, simultaneous evaporation of the liquid foaming agent. produced. The expanded 40 times the result polycyanoacrylate foam is material can occupy a volume of as much as WO 92/09651 10 15 20 25 30 PCT/GB91/02121 _ 3 _ volume of the original liquid composition. The expansion coefficient and the properties of the foam are dependent on the components used and their ratios. They are also dependent on the availabile volume for expansion. The formed polymeric foam is of a closedscell type. A distinctive feature is that the foam is covered by a thin film of polycyanoacrylate, which resembles a polycyanoacrylate glue-line and ensures excellent adhesion of the foam to the surface(s) which it has contacted. The time necessary for the onset of polymerization and foaming can be regulated from seconds to minutes by varying the type and amount of anionic initiator and/or stabilizer present in the cyanoacrylate monomer or composition. Another distinctive feature of the composition of the present invention is that it is easy to prepare, the foaming reaction takes place at room temperature and compressed ‘gases are not required or utilized. Another distinctive feature of the foamed polycyanoacrylate is that it can easily bet collapsed when contacted with solvents for polycyanoacrylates like acetone, acetonitrile, methylenechloride, N,N-dimethylformamide, butyrolactone or alkyl cyanoacetates, for example. nitromethane, Applications of the foaming composition of the present invention and the method of obtaining polycyanoacrylate plugging of ducts, adhesive bonding and foams include two major areas, i.e. pipes and vessels and, secondly, sealing of porous substrates. W0 92/0965 1 10 15 20 25 30 PCT/GB91/02121 - 9 - Using the foaming composition of the present invention temporary, permanent or semi-permanent blocking of flow of fluids in pipelines can be achieved. Gas and oil pipelines are of particular interest. Following repairs or other work on the pipeline the foam blockage can easily be collapsed by application of a suitable solvent. The main advantage of the material and method of the invention is the simplicity and speed of forming the foam, its high adhesion to the and the simplicity and speed of walls of the pipe, collapsing the foam. Using the foaming composition of the present invention blood fallopian tube sealing or other medical The above—mentioned applications are currently executed with conventional for the purpose of stopping haemorrhage and Using the foaming composition in vessel occlusion, or surgical procedures can be achieved. cyanoacrylates for female sterilization. those cases would greatly increase the success rate of the ’ present methods, ensuring excellent plugging capacity as a result of polymer expansion in the vessel. Furthermore the quantity of the cyanoacrylate introduced into the body will be reduced more than tenfold, which would greatly increase the physiological safety of the procedures. Using the foaming composition of the present invention orthopaedic casts for broken limbs can be prepared. The distinct be the preparation of the casts, their extremely low weight and advantages will speed and ease of advantages specially valuable in sufficient rigidity, emergency cases and military action. PCI‘/GB91/02121 WO 92/09651 10 15 20 25 30 -10- The cyanoacrylate monomer and the initiator must obviously be kept separate until it is desired to form the foaming composition, but the foaming agent may if desired be mixed with one or other (or both) of the monomer and the initiator to form a preblend. It is therefore convenient to provide a binary delivery nomer and.the initiator in separate system holding the mo If containers from which they may be dispensed and mixed. desired, the binary system could include a third container containing all or part of the foaming agent, and.if desired containers holding other components may be separate Such a binary or multipart delivery system forms provided. one aspect of the invention. The delivery system or kit may take the form of a syringe having an in-line static (stationary phase) mixer or of In any event, it preferably includes means spray apparatus. their to mix the components prior to, or in the process of, dispensing from the apparatus. In the case of a syringe, a thickener is preferably provided to increase the viscosity of the final composition. Preferably, the delivery system is a two-part system, in which all the components are included in the containers holding the monomer preparation and the initiator. The invention includes a preblend for forming the foaming composition, comprising the monomer and a foaming agent. The above-mentioned applications are only indicative and do not limit the scope or application of the foaming T composition of the present invention. W0 92/0965] 10 15 20 PCF/GB9]/0212] -11.. The invention is illustrated by the following examples. Example 1 In an open polyethylene cylindrical container with a diameter of 50 mm, 4 ml of pure, freshly distilled ethyl 2—cyanoacrylate are placed. To the cyanoacrylate is added a given amount of liquid N,N-dimethyl-p-toluidine. foaming agent, containing The contents are manually mixed for 3 seconds so that a clear solution is produced. The so formed composition is left static and the time lapse before the onset of expansion and the time interval of actual expansion is recorded. The volume of the expanded foam is measured and the coefficient of expansion is calculated as the ratio of the volume of the polycyanoacrylate foam to the volume of the cyanoacrylate monomer in the composition. The results are shown in Table 1. -In Table 1, the concentration of initiator is expressed as percentage by weight based on the total composition. PCT/GB9]/02121 W0 92/ 09651 ..]_2_. zoflmzmmunw uwuum mmmmmaaoo Em.O.m.« n mm m m m . m 3 3 S :3: m.2 Sod TN 32» ofl oa . . S S m . _ .. { S 3 S . . om uofi m m >Ho.o Hum wcocmusmtm 0% T . .3 u , o :0: N m nHo.o Hum wcmxwnoaomo 3 . T m 3 mm cos V.» oS.o iv 3:3 V 3 3 m . .. m :2. w » o~.o.o iv magnum mm o m wv :0: . wSBEmoHH£u m P So o iv Lfiouoasu mg m mm mo . T mm m om mm . IIIIIIIIIIIIIIIIl|ll|lllIll||lllll!llli%c o 5 mNo.o Hug mcmucwm as: an 9.; 0.. .x.:.:. . . nfimmwou Lcmmwm gown no msfiu ¢m am no uoumfiu ¢m 0» mama xnamxm NEH L .9. > Hum no aumnwemumm . uflcfl mo uwuomocmao mo ucwmm _ u cmuco oa my was 0 mcaamom A¢m. mucmmm mcflsmou ucmumumfio co vwmmn mcoauamo sou casmom H magma W0 92/0965] 10 15 20 25 30 PCI‘/GB91/0212] _ 13 - The ratio of ethyl 2-cyanoacrylate monomer to foaming agent in Table 1 was established to be the best for each pair in previous experiments. The results indicate that the most important factor in choosing the foaming agent is its boiling point and as can be seen the lower the boiling point the higher is the expansion which can be achieved. The following major consideration is the polarity and the solubility parameter of the foaming agent. produced with non-polar solvents with solubility parameters pentane, with Best results are at the lower end of the scale, e.g. 1,1,2-trichlorotrifluoroethane. solubility parameters at the other end of the scale and high polarity are normally unsuitable due to the formation of Foaming agents exceptionally brittle foams. Foaming agents with a solubility parameter similar to poly(ethyl 2-cyanoacrylate) and thus being good solvents for the foam, e.g. acetone, are also unsatisfactory due to immediate shrinkage and collapse of the foamed material. Solvents in the mid—range ‘of the solubility parameter scale and with boiling point around 80°C, like cyclohexanone, produce resilient foams. Example 2 Experiments according to the procedure described in Example 1 were carried out. Ethyl 2-cyanoacrylate was used as the cyanoacrylate monomer and 1,1,2—trichlorotrifluoroethane as Different initiators were evaluated. The ratio of cyanoacrylate to 1,1,2-trichlorotrifluoroethane and the concentration levels of the initiators were optimized in previous experiments. the foaming agent. anionic polymerization The results are presented in Table 2. PCT/GB91/02121 W0 92/ 09651 -14- mcflamcwmasm mm m mm Hum nHo.o Awcmawcuwflcwxovuz , wcflnmmosm q no mom muv mvoo.o amcmfimaue mmosm H H" moo.o mafia FH ow mm N Hazuwflue , ma ofl om Hum T oHo.o mcflcflummflm m om omv muv mooo o mcfinfluam N . oHo.o .m:ficfisHo»um m o o H.¢ -H»numaflo-z.z 0mm 0mm $.u3 ucwmm ma“ cofim nemom oa mama cofiuflmomsou nzwfloflumwoo uzmmxm mafia nauumocmao mo cw Hm< mo cofimcmmxm we mafia ummco ofiumu.wEsao> coflpmuucwucoo Hm< muoumflpflcfl coflpmufluwa do Uficowcm ucmummuflv CO vwmmp mcoflpfimo ECU cflsmom N magma lNIwHONmfl£uONcwQ, W0 92/09651 PCT/GB9] /02121 -15- The results summarized in Table 2 show that best expansion coefficients and time of expansion are achieved with N,N— dimethyl—p—toluidine and N-(oxydiethylene)benzothiazo1e—2— sulfenamide, the latter having the advantage of no odour. Piperidine gives slightly longer onset times and is very smelly. Very slow onset and expansion times can be achieved with triethylphosphine and triphenylphosphine Example 3. Experiments according to the procedure described in Example 1 were carried out. Ethyl 2-cyanoacrylate was used as the cyano- acrylate monomer. 1,1,2-Trichlorotrifluoroethane was used as foaming agent. Their ratio was 4:1 by volume. N,N—dimethyl—p— toluidine was used as initiator in 0.01% by weight of the composition. The cyanoacrylate monomer was stabilized with p—toluenesulfonic acid or trifluoromethanesulfonic acid. The results of the onset time of foaming are presented in Table 3. WO 92/09651 PCT / GB91 / 02121 -15- Table 3 Stabilized foaming comgositions Acid Concentration of acid Onset time in cyanoacrylate wt.% sec p—Toluenesulfonic O 10 _____________________________________________________——_—— p—To1uenesfilfonic 0.0003 j 14 _________________________________________________________ p—Toluenes0lfonic 0.0006 16 _________________________________________________________________ p—To1uenesulfonic 0.0012 200 0 __________________________________________________________ p—To1uenesulfonic 0.002 37 _________________________________________________________ p—To1uenesulfonic 0.005 66 _____________________________________________________________ p-Tolfienesulfonic 7O.0i 195 .___________________________________________________________ Trif1uoro— 0 10 methanesulfonic ____________________________________________________________ Trifluoro— . 1 methanesulfonic O O01 1 _______________________________________________________ Trifluoro- methanesulfonic 0'0O2 240 Trifluoro— T O 005 43 methanesulfonic ________________________________________________________ Trifluoro— I O_Ol 117 methanesulfonic _____________________________________________________________ W0 92/09551 PCT/GB91/02121 -17- The results presented in Table 3 clearly demonstrate that the introduction of sulfonic acids, which are often used commercially to stabilize the cyanoacrylate monomers, can increase the onset time of foam expansion and by regulating their level the period between mixing the composition of the present invention and its expansion into polymer foam can be controled. Example 4 Experiments according to the procedure described in Example 1 were carried out. Different types of cyanoacrylate mono- mers were used. 1,1,2—Trichlorotrifluoroethane was used as foaming agent. N,N-dimethyl—p—toluidine was used as initia- tor in amount of 0.01% by weight of the composition. The expansion coefficient data are shown in Table 4. wo 92/09651 PC!‘/GB91/02121 -13- Table 4 Foaming comgositions based on different czanoacrxlate monomers Volume ratio of Expansion Cyanoacrylate cyanoacrylate to coefficient monomer foaming agent __________________________________________________________ Methyl 2—cyanoacry1ate 4:1 13 ________________________________________,________________________ 4:1 25 Ethyl 2—cyanoaorylate _____________________________________________________________ Butyl 2—cyanoacry1ate 1:1 29 _____________________________________________________________ iso-Butyl 1:1 _ 35 2—cyanoacrylate ______________________________________________________________ Allyl 2—cyanoacrylate 1:1 20 _____________________________________________________________ 2—Methoxyethyl 2—cyanoacrylate _____________________________________________________________ 4:3 20 2—Ethoxyethyl a 4:3 15 2—cyanoacry1ate ________________________________________________________________ 2—Methoxyisopropy1 4_3 23 2-cyanoacrylate ' ________________________________________________________________ W0 92/0965] 10 PCT/GB91/02121 -19.. Example 5 Compositions based on various cyanoacrylate monomers and 1,1,2-trichlorotrifluoroethane in a volume ratio of 4:1 and containing 0.01% by weight N,N-dimethyl-p-toluidine as initiator were injected into polyethylene tubes with an internal diameter of 12.5 mm. Seconds after the injection, the composition expanded into polycyanoacrylate foam which plugged the tubes. The walls of the tubes were carefully cut and the foamed material removed. Test pieces of the foam were cut from it and tested. physical characteristics of the foams are presented in Table 5. The results of some WO 92/09651 PCT / GB9] I 02121 -20- Table 5 Physical characteristics of Qolycyanoacrylate foams 2—Cyano— Specific Tensile Elonga— Tensile Compression acrylate gravity strength tion at shear strength at monomer at break break strength 10% deforma- at break tion g/cm3 Kg/Cmz % kg/Cmz kg/cmz __________________________________________________________ Methyl 0.28 0.8 2.5 ' 0.5 5.7 _________________________________________________________ Ethyl 0.13 10.6 3.7 5.2 . 4.9 ________________________________________________________ Butyl 0.25 5.7 6.7 1.8 4.9 iso-Butyl . 0.24 3.2 3.7 3.0 5.7 _______________________________________________________ Allyl 0.18 5.0 3.0 3.0 7.3 ________________________________________________________ 2‘Meth°"Y‘ 0.41 1.6 2.0 1.9 6.5 ethyl ________________________________________________________________ 2-Ethoxy- O 7 ethyl .22 1.6 1. 1.5 5.5 ______________________________________________________________ 2—Methoxy— 0.28 1.8 2.0 1.7 4.0 isopropyl W0 92/0965] PCI‘/GB9]/02121 _ 21 - Example 6 Tubes and pipes made of cast iron, stainless steel, copper, polycarbonate, polystyrene, polyvinylchloride, polypropylene 5 and polyethylene having inside diameters from 1 mm to 100 mm were plugged with foam by injecting through a specially drilled opening a foaming composition consisting of ethyl 2 cyanoacrylate and 1,1,2-trichlorotrifluoroethane in a volume ratio of 4:1 and containing 0.01% by weight 10 N,N—dimethyl-p-toluidine. The expanded foam created an efficient plug, whose adhesion to the pipe wall was higher than the strength of the foam material itself. The pipes were hermetically sealed by the foam plug and easily withstood pressure of 10 Atmospheres. 15 In a following operation acetone was injected with a syringe through the same opening used for injecting the composition, which subsequently was also plugged with foam. In 5 seconds -to 2 minutes, depending on the size of the pipe, the foam 20 collapsed and flow through the pipe was restored. W0 92/09651 PCT / G139] / 02121 -22- CLAIMS 1,A foam-forming cyanoacrylate composition comprising a 2-cyanoacrylate ester monomer, a liquid foaming agent and a 5 polymerization initiator, for anionic polymerization of the monomer, which composition upon or after mixing polymerizes and foams:to produce a polycyanoacrylate foam. 2. A composition as claimed in claim 1, wherein the 10 cyanoacrylate monomer and the liquid foaming agent are in a volume ratio from 1:10 to 20:1. 3. A composition as claimed in claim 1 or claim 2, wherein the polymerization initiator is in an amount of from 15 0.00001% to 1% by weight of the composition. 4. A composition as claimed in any one of the preceding claims, wherein the foaming agent is an organic compound with a boiling point not higher than 100°C. 20 5. A composition as claimed in claim 4, wherein the foaming agent is miscible with the cyanoacrylate monomer.. 6. A composition as claimed in claim 5, wherein the foaming 25 agent has a solubility parameter below 9 and is nonspolar. 7. A composition as claimed in claim 4, wherein the foaming agent is pentane, hexane, heptane, 1,l,2-trichlorotriflouroethane, 30 1,1,l—trichlorotrifluoroethane, petroleum. ether, diethyl ether, cyclopentane, cyclohexane, benzene, . carbon tetrachloride, chloroform, methylcyclopentane, dimethylsulfide, 1,l—dichlororethane, 1,1,1-trichloroethane, fl WO 92/09651 10 15 20 25 30 PCT/GB91/02121 _ 23 _ perfluorohexane, mixture thereof. perfluoroheptane, 1-bromopropane or a a 8. A composition as claimed in claim 7, wherein the foaming hexane, 1,1,2-trichlorotrifluoroethane, cyclohexane or diethyl ether or is a agent is pentane, petroleum ether, mixture thereof. 9. A composition as claimed in any 'one of the preceding claims, wherein the cyanoacrylate monomer comprises one or more compounds of the formula wherein R is alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkynyl, aryl or an aromatic heterocyclic radical or is one of these moieties substituted with one or more other of the moieties, and wherein these moieties may optionally be substituted with alkoxy, carbalkoxyalkyl, halogen or another inert substituent. 10. A composition as claimed in claim 9, wherein R contains from 1 to 16 carbon atoms, the heteroatom ring members of any aromatic heterocycle being counted as a carbon atom. 11. A composition as claimed in claim 9 or claim 10, alkyl, halogenated alkyl, cycloalkyl, cycloalkylalkyl, alkylcycloalkyl, alkenyl, alkynyl, phenyl, halogenated phenyl, phenylalkyl, halogenated phenylalkyl, wherein R is PCI‘ /GB91/02121 WO 92/09651 - 24 - alkylphenyl, halogenated alkylphenyl, alkylphenylalkyl, halogenated alkylphenylalkyl, alkoxyalkyl, alkoxyalkoxyalkyl, carbalkoxymethyl or isopropylideneglyceryl. 5 10 15 20 25 30 12. A composition as claimed in claim 11, wherein R is ethyl, n-butyl, iso-butyl, 2-methoxyethyl, 2-ethoxyethyl or 2-methoxyisopropyl. 13. A composition as claimed in any one of the preceding claims, wherein the initiator is pyridine, aminopyridine, vinylpyridine, methoxyethylpyridine, piperidine, picoline, N,Nedimethyl-p—toluidine, lutidine, N,Nsdimethyl-o-toluidine, N,N4dimethyl-m-toluidine, triphenylphosphine, triethylphosphine, tribenzylamine, triethylamine, benzyldimethylamine, diethylenetriamine, benzyltriethylamine, tribenzylamine, poly(4-vinylpyridine), a _ calixarene, p a tertiary amine-S03 complex, polyethyleneglycol, a phenolformaldehyde resin, vinylimidazole, triethanolaminatotitanium, an aminosilane, a phosphite, a metal acetylacetonate, N—(oxydiethylene) benzothiazole-2-sulfenamide, bismuth dimethyldithiocarbamate, an alcohol, a base or a hydroxyl or amine group containing compound. 14. A composition as claimed in claim 13, wherein the initiator is N,N-dimethyl-p-toluidine or N6(oxydiethylene) benzothiazole-2-sulfenamide. 15. A composition as claimed in any one of the preceding claims and which further comprises a free-radical polymerization inhibitor or an anionic polymerization- /A W0 92/09651 PCI‘/GB91/02121 - 25 - inhibitor in an amount insufficient to inhibit the initiator, or both. 16. A composition as claimed in any one of the preceding 5 claims and further comprising another reactive monomer or a reactive resin or oligomer, a thickener, a viscosity regulator, a rubber, a plasticizer, a toughener, a compatibilizer, a thixotropic agent, a colourant, a deodorant or a mixture thereof. ' 10 17; A poly(2-cyanoacrylate ester) foam, the polymer 15 optionally including a minor amount of one or more other monomer units than 2-cyanoacrylate ester unitsor.a reactive resin or oligomer. 18. A foam as claimed in claim 17, wherein the 2-cyanoacrylate ester is as defined in any one of claims 9 20 to 12. ’ 19. A method of forming a poly(2-cyanoacrylate ester) foam, comprising formingt a composition as defined in any one of claims 1 to 16 and allowing the monomer to polymerize and 25 form a foam. 20. A method as claimed in claim 19. wherein the components of the composition are mixed together in a static mixer or in a spray. 30 21. A kit or device for forming a poly(2-cyanoacrylate ester) foam, comprising a first container containing 2-cyanoacrylate ester monomer and a second container W0 92/0965] 10 15 20 25 30 PCT/GB91/02121 _ 25 - containing a polymerization initiator for anionic polymerization, the kit additionally containing a liquid foaming agent in the first container, in the d container or in any combination second container or in a thir thereof. A kit or device as claimed in claim 21 , wherein the is as defined in any one of claims 9 to 12, the foaming agent is as defined in any one of claims 4 to 8, initiator is as defined in claim 13 or claim 14, the monomer and the foaming agent are in a volume ratio of from 1:10 to 20:1, and/or the polymerization initiator is in an amount of from 0.00001% to 1% by weight of the total contents of the ion inhibitor or a free radical polymerization polymerizat containers inhibitor or both, and/or one or more of the additionally contains one or more of the further components defined in claim 16. 24. A.kit or device as claflm§iin.any one of claims 21 to 23 Which comprises a two part o£_three‘part syringe. - 25. A kit or device as claimed in any one of claims 21 to p23 wherein the first and second containers and any third are connected by ducts to a spray head for mixing provided to container the contents of the containers of the containers through the ducts to and means is expel the contents the spray head. W0 92/09651 PCT/GB91/02121 -27- 26.A delivery system for forming a composition as defined in any one of claims 1 to 16 the system comprising the monomer and the initiator in separate containers from which they may be dispensed, the foaming agent being included in 5 said containers and/or in a separate container, and the system optionally including means to mix the container contents before or as they are dispensed from the system. 27. A preblend for forming a cyanoacrylate foam, comprising 10 a 2-cyanoacrylate ester monomer and a liquid foaming agent. 28. A preblend as claimed in claim 27, wherein the cyanoacrylate monomer and the foaming agent are in a volume ratio of from l:lD to 20:1, the foaming agent is as defined 15 in any one of claims 4 to 8 and/or the cyanoacrylate monomer is as defined in any one of claims 9 to 12. 29... A preblend as claimed in claim 27 or claim 28 and which further comprises a free-radical polymerization inhibitor, 20 an anionic polymerization inhibitor or both, and/or one or more further components as defined in claim 16. 30. A method of blocking a pipe, comprising placing in the pipe a composition as defined in any one of claims 1 to 16 25 and allowing the composition to polymerize to form a foam which blocks the pipe. 31. A method as claimed in claim 30, wherein the pipe is blocked temporarily and is subsequently unblocked by 30 applying to the foam a solvent therefor. WO 92/09651 10 15 20 25 PCT /GB91/02121 -28.. 32. A.method of forming a cast, for example for a broken or injured limb, comprising applying a composition as defined in, any one of claims 1 to 16 to the limb or other body around which the cast is to be formed and allowing the composition to polymerize and foam to fcrm.a cast. 33. A method of occluding or stopping a blood vessel, fallopian.tube or other tubular part or a; human or animal body, comprising applying to the tubular part a composition as defined in any one of claims 1 to 16 and allowing the composition to polymerize to form a foam occluding to stopping the tubular part. 34. The use of 2-cyanoacrylate ester monomer as a starting material to form a polyoyanoacrylate foam. 35. The. use of claim 34, wherein the monomer is as defined in any one of claims 9 to 12. 36. The use of an organic liquid with a boiling point of no than. 100°C as a foaming agent. to form a polycyanoacrylate foam. greater 37. The use of claim 36, wherein the organic liquid is as further defined in any one of claims 6 to 8. 38. A composition as defined in any one of claims 1 to 16 for use in the treatment of the human or’ animal body by surgery or therapy. 39. A method of forming a polymer foam on or aroundjapart of the human or animal body, comprising applying a composition as defined in any one of claims l to 16 on'or around the part. INTERNATIONAL SEARCH REPORT Intemational Appliution No PCT/GB 91 /0 2 1 21 I. CLASSIFICATION OF SUBJECT MATTER (if several classification symbols apply, indicate all)“ According to International Patent Classification (IPC) or to both National Classification and IPC Int.Cl.5 C 08 J 9/14 // A 61 L 15/12 C 08 L 35:04 II. FIELDS SEARCHED Minimum Documentation Searcbed7 Classification System Classification Symbols Int.Cl.5 C 08 J A 61 L Documentation Searched other than Minimum Documentation to the Extent that such Documents are Included in the Fields Searched‘ Ill. DOCUMENTS CONSIDERED TO BE RELEVANT9 Citation of Document, " with indication, where appropriate, of the relevant passages 12 Relevant to Claim No.” X,P Chemical Abstracts, vol. 115, no. 6, 12 August 1991, (Columbus, Ohio, US), see abstract no. 51548k, & JP,A,3091542 (TORAY INDUSTRIES) 17 April 1991, see abstract DE,A,3421360 (REICH SPEZIALMASCHINEN GmbH) 12 December 1985, see claims 1-3 FR,A,2359170 (POLYMERICS INC.) 17 February 1978, see claims 1-2 FR,A,2610828 (MOSKOVSKY GOSUDARSTVENNY MEDITSINSKY INSTITUT) 19 August 1988, see claims 1-3 _.._ ../_ later document published after the intemational filing date ° Special categories of cited documents : ‘O or priority date and not in conflict with the application but , ,, d . . . . _ _ V _ A £:::1‘:;‘e'ddg'L';“§f';':rfi:'l:::lr::::;:’£e‘he 3" "h'°h '5 “°‘ ttiiinpnderstand the principle or theory underlying the ‘Qt: gfigligrdgttfument but published on or after the intemational rxu document of pafiicular relevanoe; the chimedjnvemon 'L" document which may throw doubts on priority claim(s) or 3:33:32 2: ‘i§3§i§1?5§ds§'e'LV°' or “mm be considered ‘O which is cited to establish the publication date of another IYR documem of - . - - - . . . . . particular relevance, the claimed invention °'m'°" °' °"'°"_5p°°'a' "Q50" (35 specmed) cannot be considered to involve an inventive step when the ‘'0'’ document referring to an oral disclosure, use, exhibition or document is combined with one or more other such docu- other means ments, such combination being obvious to a person skilled "P" document published prior to the international filing date -but "' ‘he 3"‘ later than the priority date claimed "'&” document member of the same patent family IV. CERTIFICATION Date of the Actual Completion of the International Search 06-03-1992 International Searching Authority EUROPEAN PATENT OFFICE Date of Mailing of this International Search Report 0 9. 0.4. 92 Signature of Authorize! Officer , /’ 1 u.:=zz.-1. 1'0?-