GB2060669A - Anaerobically Curing Rubber Adhesive Compositions - Google Patents

Abstract

The compositions are cold vulcanisable and comprise a diene rubber and an anaerobic monomer together with a catalyst system for anaerobic curing. The polymerised product possesses rubberlike properties. Such compositions are useful in the form of a sheet, tape, ribbon or latex, are solvent and pressure resistant and are used for sealing, gaskets, adhesives and as support members. The formed products may be coated with a thin air-permeable polymeric layer.

Description

SPECIFICATION Anaerobically Curing Rubber Adhesive Compositions This invention relates to anaerobically curing rubber adhesive compositions.

Anaerobically curing adhesives compositions are known and their uses have become progressively more important in industry as sealants, gaskets and for their adhesive properties.

Anaerobic sealants and adhesives are conventionally applied in a form from water-like to lightweight grease consistency. The composition in this form "wets" the surface to be bonded.

There are disadvantages to the conventional anaerobic compositions presently on the market for certain uses thereof.

The areas of application of anaerobic compositions can be vastiy increased if the composition is in a form having solid characteristics. In addition many areas of application, such as gaskets, requires that the polymerised (cured) composition be resistant to solvents and retain flexibility.

Synthetic rubbers have many of these desired properties, but their use is limited due to the relatively drastic means necessary to cure rubber, such as, high temperatures or irradiation.

The present invention combines rubber technology and anaerobic technology to obtain a rubber composition which is curable under anaerobic conditions.

An anaerobic system is usually defined as a system which remains stable in its compounded form in the presence of oxygen, but which polymerises to a higher polymeric state in the absence of oxygen.

This, in effect, means that the presence of oxygen hinders or delays polymerisation (curing).

Preferably anaerobic curing occurs at ambient temperatures; however, the rate of polymerisation depends upon the monomer, initiator, and whether or not inhibitors and/or accelerators are present.

Thus, the term anaerobic curing, has been and is used to refer to polymerisation that occurs also at higher than ambient temperatures, the prime factor being that the curing is inhibited by the presence of oxygen but takes place in its absence or is reduced concentration of oxygen. Elevated temperatures and/or metals will also accelerate the polymerisation.

According to the present invention, there is provided anaerobically curing rubber compositions which can be applied preferably from or as sheets, tapes and the like and which, when cured, have rubber-like and flexible characteristics.

More particularly the present invention provides a cold vulcanisable, rubber composition comprising a) 30% to 80% by weight of a copolymer which is acrylonitrile/butadiene having an average molecular weight of from about 50,000 to about 500,000 and having terminal or pendent vinyl groups, acrylonitrile/butadiene having terminal reactive carboxy, mercapto or amino groups, polybutadiene, polyisoprene, acrylonitrile/butadiene/styrene, or butadiene/styrene; b) 70% to 20% by weight of an anaerobic monomer which is soluble in or miscible with the said copolymer; c) 0.1 to 7% by weight based on the weight of the said anaerobic monomer of a catalyst system; d) an accelerator; and e) a stabiliser, the said composition being capable of being polymerised, under anaerobic conditions to a high molecular weight material with vuldanised, rubber-like properties, having at least 65% non-extractable solids.

For convenience the curing process of the compositions of this invention will be termed "cold vulcanisation" and is defined as a process of curing, by anaerobic means, of liquid long-chain segments or unvulcanised gum into polymeric material of high molecular weight having appropriate values of crosslink density to secure rubberlike properties. The rubberlike properties (rubber elasticity) are all those properties from a high elastic response to a tough flexible material of high modulus. A definition of rubber elasticity is found in F. W. Billmeyer's Textbook ofPolymer Science (John Wiley & Sons, Fourth Printing, 1966), p. 189.

The composition of this invention includes a synthetic rubber composition in combination with one or more anaerobic resins, one or more initiators, an accelerator and an inhibitor.

The synthetic rubber composition may also contain fillers such as titanium dioxide, glass, nylon fibres and/or polytetrafluoroethylene (e.g. Teflon-Teflon is a Trade Mark).

In one embodiment of this invention the anaerobically curing rubber composition is formed into a tape or ribbon and may be coated with nylon or another polymer. A tape or ribbon is defined as an article of manufacture in which the width is less than the elongated dimension.

In general the synthetic rubber has a molecular weight of about 50,000 to 500,000 and is present in a range from about 30 to about 80% by weight based on the total weight of the total composition. The anaerobic monomer, which must be soluble or completely miscible with the synthetic rubber is present in a range of from about 70 to about 20% by weight based on the total weight of the resin.

Fillers, when present, are in the range of from about 5 to about 20% by weight of titanium dioxide, glass and/or nylon fibres and from about 0% to about 10% by weight of polytetrafluoroethylene (Teflon). Both weights are based on the total weight of synthetic rubber.

One or more initiator, in a total amount in the range of about 0.1 to about 7% by weight ofvthe weight of the anaerobic monomer is incorporated into the composition.

Accelerators, when present, are in the range of about 0.1 to about 7% by weight Inhibitors are present in the range of about 25 to about 1000 ppm.

The present invention relates to compositions which when cured anaerobically attain rubberlike properties.

As used herein, the term- anaerobic monomer is a monomer having at least one and preferably two polymerisable acrylate ester moieties, normally at the ends of a backbone which will polymerise or cure in the presence of an initiator upon the substantial exclusion of oxygen or air.

One of the most preferred groups of anaerobic monomers, which can be used in this invention, are polyacrylate esters which have the following general formula:

wherein R1 represents hydrogen, lower alkyl of from one to four carbon atoms, hydroxyalkyl of from one to four carbon atoms, or

wherein R2 is hydrogen, halogen or lower alkyl of from one to four carbon atoms; R3 is a hydrogen, hydroxyl or

m is an integer equal to at least 1, e.g. from 1 to 1 5 or higher, and preferably from 1 to 8 inclusive; n is an integer equal to at least 1, e.g. 1 to 20 or more; and p is O or 1.

The polyacrylate esters used in accordance with the invention and corresponding to the above general formula are exemplified by but not restricted to the following materials: di, tri- and tetramethylene glycol dimethacrylate, dipropylene glycol dimethacrylate, polyethylene glycol dimethacrylate, di(pentamethylene glycol)dimethacrylate, tetraethylene glycol diacrylate, tetraethylene glycol di-(chloroacrylate), diglycerol diacrylate, diglycerol tetramethacrylate, tetramethylene dimethacrylate, ethylene dimethacrylate, meopentyl glycol diacrylate, trimethylol propane triacrylate, the reaction product of hydrogenated Bisphenol A with 2,4-tolylene diisocyanate and 2-hydroxymethacrylate, and the reaction product of methylenediphenylisocyanate and 2-hydroxymethacrylate or 3-hydroxy-methacrylate. The foregoing monomers need not be in the pure state, but may comprise commercial grades in which inhibitors or stabilizers, such as quinones are included.

Monoacrylate esters which may be used are particularly those esters in which the non-acrylate portion of the ester contains a hydroxyl, mercapto, or amino group, or other reactive substituent which serves as a site for potential cross-linking with itself and/or the synthetic rubber compound.

The choice of anaerobic monomer that can be used in this invention is dependent upon the particular synthetic rubber selected. The anaerobic monomer must be soluble or completely miscible with the synthetic rubber composition.

Solubility or miscibility of monomer in the rubber may be easily determined as follows: (1 ) if the synthetic rubber is a liquid and the anaerobic monomer is a liquid, then visual inspection will show solubility or miscibility; (2) if the synthetic rubber has solid characteristics then after mixing the monomer with the rubber and placing the compounded material on paper, an oily wet spot appears on the paper if the monomer is not soluble in or completely miscible with the rubber.

The term copolymer as used in this invention refers to those commonly known synthetic rubber copolymers which are preferably polar and of sufficient molecular weight so that their viscosity is sufficiently high to form stable compositions with the monomers. The preferred copolymers have terminal and/or a pendant vinyl or reactive sites for possible reaction with the anaerobic monomers and are preferably unvulcanised gums.

Examples of copolymers or rubbers which may be used in this invention are acrylonitrile/butadiene copolymers having reactive terminal groups such as carboxy, mercapto or amino; polybutadiene; polyisopropene; butadiene/styrene, polyurethanes and acrylonitrile/butadiene/styrene.

The acrylonitrile/butadiene is available from B. F. Goodrich Co. under their trade name Hycar and the preferred copolymer has an average molecular weight in the range of from about 50,000 to about 500,000.

The butadiene-styrene copolymer is designated SBR and generally has a ratio of butadiene to styrene of approximately 78:22.

The acrylonitrile/butadiene/styrene copolymers preferably have an average molecular weight of from about 5,000 to about 100,000 and contains from about 1 5 percent to about 35 percent acrylonitrile and from about 1 5 percent to about 35 percent butadiene.

The catalyst or initiator for the system according to the invention is generally composed of a peroxy compound and a co-initiator.

The preferred peroxy initiators are hydroperoxy initiators and most preferably the organic hydroperoxides which have the formula R400H, wherein R4 generally is a hydrocarbon radical containing up to about 1 8 carbon atoms, preferably an alkyl, aryl or aralkyl radical containing from one to 1 2 carbon atoms. Typical examples of such hydroperoxides are cumene hydroperoxide, tertiary butyl hydroperoxide and methyl ethyl ketone hydroperoxide. However, other peroxy initiators, such as hydrogen peroxide, dihydroperoxides or materials such as certain organic peroxides or peresters which hydrolyse or decompose to form hydroperoxides and di-hydroperoxides and di-hydroperoxides can frequently be used. Examples of such peroxy initiators are benzoyl peroxide and 2,5-dimethylhexyl-2,5dihydroperoxide. These compounds are known in the literature.

Coinitiators which are useful in the present invention include the known hydrazine derivatives that are capable of initiating free radical polymerisation at temperatures below about 1 0O0C., and especially compounds having the formula

wherein R5 is alkyl, preferably lower alkyl containing 1-6 carbon atoms, either straight chain or branched, more preferably methyl, ethyl or isopropyl; cycloalkyl containing up to about 8 carbon atoms; alkenyl containing up to about 10, preferably 2-5, carbon atoms; cycloalkenyl containing up to 10, preferably up to about 6, carbon atoms; aryl, including halo-substituted aryl, hydroxy-substituted aryl, nitro-substituted aryl, and aryl substituted by lower alkyl or alkoxy groups containing one to about 6 carbon atoms. R6 may be hydrogen or any one of the radicals specified for R5 and in addition may be an amino or substituted amino group, or a carbonyl group to which is connected an unreactive group such as a lower alkyl containing from one to about 4 carbon atoms.

Representative compounds according to the above formula include, but are not limited to, 1 - acetyl-2-phenylhydrazine, 1 -acetyl-2(p-tolyl)hydrazine, 1 -benzoyl-2-phenylhydrazine, 1 (1',1 ',1 '- trifluoroacetyl)-2-phenylhydrazine, 1 ,5-diphenylcarbohydrazine, 1 -formyl-2-phenylhydrazine, 1 -acetyl- 2-(p-bromophenyl )hydrazine,1 -acetyl-2-(p-nitrophenyl)hydrazine, 1 -acetyl-2-(pmethoxyphenyl) hydrazine, 1 -acetyl-2-(2 '-phenylethyl)hydrazine and 1 -acetyl-2-methylhydrazine.

Efficacy of the accelerators for use in accordance with the invention appears to require the presence of a proton on each of the nitrogen atoms, but no more than one proton on each nitrogen atom. If this criterion is met, the precise nature of the R groups does not appear to be critical, provided, of course, that the R groups may not be selected so as to interfere substantially with the storage properties of the adhesive composition or with the performance of the accelerator for its intended purpose. Thus, the selection of specific R groups and combinations thereof is deemed to be a matter of experimentation and choice. It will, of course, be appreciated by those skilled in the art that optimum selection of R groups may depend upon the curable ester monomer or mixture of monomers, as well as the initiator or optional co-accelerator used.

The accelerators may be used in concentrations from about 0.001 to about 10 percent or more by weight based on the total composition. Below this lower limit, little effect will be observed. The upper limit is not critical since significant improvement usually will not be found above concentrations of about 5% by weight. As a practical matter, a concentration range of 0.1-2.0% by weight will provide optimum over-all benefit and this range is therefore especially preferred.

Accelerators are also frequently used in the compositions of this invention. Examples include organic amides such as formamide and succinimide and the like; tertiary amines such as tributyl amine and triethylamine and the like, aromatic tertiary amines such as dimethyl p-toluidine and the like; and organic sulphimides, such as benzoic sulphimide and the like. Accelerators when present are in the range of from about 0.1 to about 7% by weight, and preferably between 2 and 3% by weight.

Stabilizers or inhibitors used according to the invention include benzoquinone, naphthaquinone, hydroquinones, monomethyl ether of hydroquinone, sterically hindered phenols and the like. The concentration of inhibitors is in the range of from about 25 to about 1000 ppm.

The products of this invention can contain any other ingredient which does not materially change the anaerobic properties or interfere with the processing of the compositions. Examples of such additional ingredients are fillers, such as titanium dioxide, polytetrafluorethylene (Teflon), glass, nylon fibers and the like which for convenience are usually added to the copolymer; colouring agents, plasticisers, and the like.

The compositions or products of this invention can be prepared in a number of ways, as for example, in the form of films, tapes, sheets or coated on a releasable backing. The composition may be extruded, rolled or deposited from a solution, slurry or latex, depending upon the use intended for the product and the physical properties of the compounded formulation. The solution, slurry or latex may be used "as is" without an intermediate deposition on another backing, such as a paint.

The products formed from the compositions of this invention have particular utility when applied, as a tape, to threaded members such as pipe fittings. In this application it replaces the presently used Teflon tape and gives superior results as to sealing and is resistant to the effects of pressure and solvents. In curing, the product will retain its flexible characteristic and if applied to threaded members, such as pipe threads, the cured product will provide both a sealing and locking function.

For convenience in storage and use, the products of the compositions of this invention may be coated with a thin layer of a polymeric material, such as nylon. The polymeric coating while sufficiently thick to permit rolling the tape and preventing its sticking to itself it is still thin enough to permit air to permeate through the coating to the tape.

For coating with a polymeric coating, the coating material should be soluble in alcohol and is usually deposited on the unvulcanised polymeric composition from an alcoholic solution preferably methanol. Nylon 6-12 (DePonts Elvamide 8061) and nylon 12-12 (Vestamid X1874, X2 191 and X2302) have been used for coatings.

The products of the invention disclosed herein, regardless of whether in their natural or preapplied form, are shelf stable items capable of withstanding normal storage and shipping conditions. They will not polymerise (cure) as long as maintained in reasonably thin sheets (such as about one half inch or less) and in contact with air or other supplies of oxygen. When confined between non-porous surfaces or otherwise placed in an oxygen-free atmosphere, curing of the composition occurs. The cured product has the characteristics of a vulcanised rubber and may consist of the reaction product of the copolymer and monomer, the complete intermeshing of the copolymer in the polymerised monomer or a combination of both.

The polymerised product, which has the characteristics of a vulcanised rubber is distinguishable from the unpolymerised reaction products by its extractibility. The unpolymerised reaction products are soluble in organic solvents whereas the polymerised product is insoluble in or non-extractible by organic solvents. The polymerised product is at least 75% and preferably 80% non-extractible.

The product form after curing retains its flexibility, forms a seal which withstands 1 500 to 2500 psi pressure and is resistant to solvents. These characteristics are retained over a wide temperature range of from about --540 to about 2040C.

While curing will normally take place at room temperature, the time required to achieve curing can be shortened by subjecting the assembly containing the composition to moderate temperatures, such as from about 380C to about 930C.

The sodium salt or ethylenediamine-tetracetate, when used in the formulation, may be added either to the monomer composition or to the copolymer-monomer composition.

The following Examples are given to demonstrate typical compositions within the scope of the invention disclosed herein, and methods of preparation and use of these compositions. The Examples are not intended to be limitations upon the invention. Unless stated to the contrary, all ratios and percentages in the Examples are on a weight basis.

Example 1 An anaerobic curing polymerisable monomer formulation was prepared by mixing the ingredients described in Table 1 in the approximate proportion indicated.

Table 1 Weight Ingredient (Gms) Polyethyleneglycol dimethacrylate (average molecular weight 330) 100 1-Acetyl-2-phenylhydrazine 0.002 benzoic sulphimide 1.6 cumene hydroperoxide 3.0 1 ,4-p-Naphthaquinone solution (100 ppm in methanol) 0.2 To a mixture consisting of 50 grams acrylonitrile/butadiene (Hycar 1492) and 20 grams of titanium dioxide, blended in a Waring blender, was added 25 grams of the mixture of Table 1 and 1 gram of a solution of sodium ethylenediaminetetraacetate (73.5% methanol, 23% water and 3.5% sodium ethylenediaminetetraacetate).

The resultant mixture was processed in a rubber roll mill until the lumps disappeared and then extruded through a slit die about 0.508 mm (20 mil) thick. The extruded material was then passed through modified heated chill rolls (only one roll was heated) having a gap approximately 762 microns (0.003 mols).

The resultant material, which was in a ribbon form about 0.0508 to 6.35 mm (0.002 to 0.250 inches) thick, was applied to a release paper strip and wound on takeup spools.

Example 2 A copolymer--anaerobic monomer mixture was prepared according to the directions of Example 1.

The resultant mixture was extruded through a slit die about 0.508 mm (20 ml) thick. The extruded material was then passed through modified heated chill rolls as in Example 1.

On leaving the chill roll (calender rolls) the material was passed through a nylon 6-12 solution (67% nylon 6-12, in methanol) and then through a column of air heated to about 520C. The methanol was evaporated in the heated air process coating the rubber tape with a layer of nylon about 0.0127 to 0.0254 mm (0.5 to 1.0 mil) thick and the coated tape was then wound on a paper spooi without any paper layer separating the layers of tape.

To use the tape, the tape is placed on the threads and stretched to break the nylon coating.

Example 3 To a mixture consisting of 50 grams acrylonitrile/butadiene (Hycar 1492), 1 9.5 grams of titanium dioxide and 0.5 grams Teflon, blended in a Waring blender was added 30 grams of the mixture of Table 1 and 1.5 grams of a solution of sodium ethylenediaminetetraacetate (73.5% methanol, 23% water and 3.5% sodium ethylenediaminetetraacetate).

The resultant mixture was processed in a rubber roll mill until the lumps disappear and then extruded through a slit die about 0.508 mm (20 mil) thick. The extruded material was then passed through a modified heated chill roll as in Example 1.

On leaving the calender rolls the material was passed through about a 6 to 7% nylon 6-1 2 solution (in methanol) and then through a column of air heated to about 520C. The methanol was evaporated in the heated air process coating the rubber tape with a layer of nylon.

This tape, in its uncured state has a shelf life in excess of one year. In its cured state, the tape has a percent elongation of 470%, a bulk tensile strength of 69 kg/cm2 (981 psi) and has an operating range of from about -540C to about 2040C (-650F to about 400 OF).

The tape was applied to a 0.95 cm (3/8 inch) malleable iron Tjoint and torqued to 4.149 kilogram-meters (30 ft.-lbs.) and subjected to stress tests with the following results: a) seals, after immediate assembly, orwhen cured 24 and 48 hours, did not leak when subjected to hydraulic pressure exceeding 141 kg/cm2 (2000 psi); b) no leakage occurred when the assembled T's (cured for 24 hours), were subjected to temperatures of from about 930C to about 2040C (about 2O00F to about 4000 F) for a period of 500 hours, and subjected to pressures of about 105.5 kg/cm2 (1500 psi); c) no leakage occurred at pressures to 211 kg/cm2 (3000 psi) (after the assembled T's cured for 24 hours), when immersed in the following solvents, at the temperatures indicated for eight weeks:: transmission fluids (1490C, 3000F); motor oii (1490C, 3000F); 50% glycol/water (1320C, 2700F); gasoline (820C, 1800 F) and air (870C, 1 880F).

d) several T's (cured for 24 hours) that have been exposed to 95% humidity at 580C (1000F) for 1000 hours showed no leaks after pressuring to 141 kg/cm2 (2000 psi).

Example 4 The mixture and process of Example 1 was repeated using t-butylhydroperoxide in place of cumene hydroperoxide.

Example 5 To a mixture of 75 gms acrylonitrile/butadiene (Hycar 1494) and 20 gms titanium dioxide, blended in a Waring blender was added 25 gms of the mixture of Table 1 and 1 gram of a sodium ethylenediaminetetraacetate solution (73.5% methanol), 23% water and 3.5% sodium ethylenediaminetetraacetate).

The resultant mixture was processed in a rubber roll mill and passed through calender rolls into a film material 0.0508 mm (0.002 inches) in thickness.

Example 6 To 1 86 grams of a 20% Hycar 1 492 solution, in methylethylketone, was added in sequence, ensuring complete solution of a compound or mixture before the addition of the subsequent compound or mixture, 40 grams triethyleneglycoldimethacrylate; 22.5 grams of an 80% solution, in toluene, of a dimethacrylate formed from the reaction product of toluene diisocyanate hydrogenated Bisphenol A and 2-hydroxethylmethacrylate; and 2.4 grams of 2,5-dimethyl-hexyl-2,5-dihydroperoxide. The temperature through the addition was maintained below 400 C.

The resultant solution was coated onto a release paper and the solvent evaporated leaving a dried uncured film 0.0508 to 0.254 mm (0.002 to 0.010 inches) in thickness. Drying of the film (evaporation of solvent) should occur at no higher temperature than 520C.

Example 7 Acceptable uncured tape and sheet materials are obtained using the following copolymers and anaerobic monomer in the procedure of Examples 1,2 and/or 5.

Copolymer Monomer a) butadiene/methacrylate having polyethyleneglycol-dimethacrylate pendenate unsaturation b) acrylonitrile/butadiene lauryl methacrylate c) butadiene/styrene tetramethyleneglycol-dimethacrylate d) acrylonitrile/butadiene having terminal carboxy groups 3-hydroxypropylmethacrylate e) butadiene/styrene 80% styrene/20% pentaethylene glycoldimethacrylate f) butadiene/acrylate/methacrylate pentaethyleneglycol-di methacrylate g) acrylonitrile/butadiene 2-hydroxyethylmethacrylate The processing of the final product by extrusion, calendering or deposition from solution is dependent upon ease of operation and physical properties of the product. Most products are a gum or pliable solid which can be extruded without the use of an excessive amount of force. Should the product be of a nature that is not easily extrudable, then it can be processed through calender rolls or by deposition from solution.

Claims (23)

Claims

1. A cold vulcanisable, rubber composition comprising a) 30% to 80% by weight of a copolymer which is acrylonitrile/butadiene having an average molecular weight of from about 50,000 to about 500,000 and having terminal or pendent vinyl groups, acrylonitrile/butadiene having terminal, reactive carboxy, mercapto or amino groups, polybutadiene, polyisopropene, acrylonitrile/butadiene/styrene, or butadiene/styrene; b) 70% to 20% by weight of an anaerobic monomer which is soluble in or miscible with the said copolymer; c) 0.1 to 7% by weight based on the weight of the said anaerobic monomer of a catalyst system; d) an accelerator; and e) a stabiliser, the said composition being capable of being polymerised, under anaerobic conditions to a high molecular weight material with vulcanised, rubber like properties, having at least 65% non-extractable solids.

2. A composition as claimed in Claim 1, wherein the anaerobic monomer has the general formula

wherein R1 represents hydrogen, lower alkyl of from one to four carbon atoms, hydroxy alkyl of from one to four carbon atoms, or

where RZ is hydrogen, halogen or lower alkyl of from one to four carbon atoms: R3 is hydrogen hydroxyl or

m is an integer equal to at least 1; n is an integer equal to at least 1; and p is 0 or 1.

3. A composition as claimed in Claim 1 or 2, wherein the copolymer is acrylonitrile/butadiene having terminal or pendent vinyl groups and having an average molecular weight of from about 50,000 to about 500,000.

4. A composition as claimed in any of Claims 1 to 3, also containing a filler in an amount in the range of about 5% to about 20% by weight based on the total weight of the composition.

5. A composition as claimed in any of Claims 1 to 4, in which the catalyst system comprises a peroxy initiator which is hydrogen peroxide, a hydroperoxide having the general formula R400H wherein R4 is an alkyl, aryl or aralkyl radical having 1 to 12 carbon atoms, a peroxide, a perester or a dihydro peroxide, and as a co-initiator a hydrazine derivative capable of initiating free radical polymerisation at a temperature below about 1000C.

6. A composition as claimed in Claim 5, wherein the peroxide initiator is cumene hydroperoxide and the co-initiator is 1-acetyl-2-phenylhydrazine.

7. A composition as claimed in any of Claims 1 to 6, wherein the accelerator is an organic amide, a tertiary alkyl amine, an aromatic tertiary amine or an organic sulphimide.

8. A composition as claimed in Claim 7 wherein the accelerator is an organic sulphamide.

9. A composition as claimed in Claim 8 wherein the organic sulphimide is benzoic sulphimide.

1 0. A composition as claimed in any of Claims 1 to 9, wherein the stabiliser is benzoquinone, naphthaquinone, hydroquinone, nonomethyl ether of hydroquinone or a sterically hindered phenol.

11. A composition as claimed in Claim 10, wherein the stabiliser is naphthaquinone.

12. A composition as claimed in any of Claims 1 to 11, wherein the anaerobic monomer is polyethylene glycol dimethacrylate.

1 3. A composition as claimed in Claim 12, wherein the polyethyleneglycol dimethacrylate has an average molecular weight of about 330.

14. A composition as claimed in any of Claims 1 to 13, wherein the copolymer is present in an amount in the range of about 60 to about 75% by weight.

1 5. A composition as claimed in any of Claims 1 to 14, wherein the anaerobic monomer is present in an amount in the range of about 20 to about 50% by weight.

1 6. A composition as claimed in any of Claims 1 to 1 5, wherein the composition includes a filler which is titanium dioxide in an amount of about 5 to about 20% by weight or polytetrafluorethylene in an amount of about 0 to about 10% by weight, the total weight of filler not exceeding about 20% by weight, the said percentage being based on the total weight of the composition.

1 7. A composition as claimed in Claim 1 6, wherein the filler is a mixture of titanium dioxide in an amount of about

18 to about

19.5% by weight and polytetrafluorethylene in the range of about 0.5 to about 2% by weight.

1 8. A composition as claimed in Claim 16, wherein the filler is titanium dioxide in an amount of about 18 to about 20% by weight.

1 9. A cold vulcanisable, rubber composition substantially as described with particular reference to any of the Examples.

20. An article in the form of a ribbon having a thickness in the range of from about 0.0508 mm to about 6.35 mm, adapted for use as a sealant and formed from a composition as claimed in any of Claims 1 to 1 9.

21. An article as claimed in Claim 20, in which the ribbon is coated with a polymeric coating in a thickness of from about 0.0127 to 0.0254 mm the coating permitting air to reach the rubber composition.

22. An article as claimed in Claim 21, wherein the polymeric coating is nylon 611.

23. An article in the form of a sheet having a thickness in the range of from about 0.0508 mm to about 0.381 mm, adapted for use in the preparation of gasketing material or as a support material and formed from the composition as claimed in any of Claims 1 to 19.