this invention relates to a dimethacrylate compound represented by the structure : ## str13 ## where ## str14 ## is a saturated , 6 membered , monocyclic , hydrocarbyl ring system ; r 1 , r 2 and r 3 are the same or different and are hydrogen or alkyl or alkoxy groups having 1 to 12 carbon atoms ; and r 4 and r 5 are the same or different and are hydrogen or groups of the formula : ## str15 ## where r 6 is an aliphatic , aromatic or cycloaliphatic group having 1 to 14 carbon atoms , provided that at least one of the groups r 4 and r 5 is a group of the formula : ## str16 ## dimethacrylate compounds of this formula are referred to hereinafter as compounds of the present invention . a preferred compound of the present invention is represented by the above formula when r 1 , r 2 and r 3 are each hydrogen . it will be understood that structures given herein are intended to connote all possible sterioisomers and combinations thereof . although not wishing to be strictly limited to any particular means for forming the compounds of the present invention , it is noted that these compounds may be described as adducts of isocyanates with adducts of methacrylic acid with 1 , 4 - bis ( glycidoxymethyl ) cyclohexane or ring substituted derivatives thereof . thus , for example , methacrylic acid may be reacted with a 1 , 4 - bis ( glycidoxymethyl ) cyclohexane compound of the formula : ## str17 ## where ## str18 ## r 1 , r 2 and r 3 are defined as above . thus , the saturated 6 membered , monocyclic , hydrocarbyl ring represented by ## str19 ## may be substituted by alkyl or alkoxy groups in up to 3 positions . in this regard , alkyl or alkoxy groups may be substituted once in each of the 1 , 2 , 3 , 4 , 5 or 6 positions or even twice in each of the 2 , 3 , 5 or 6 positions . as mentioned previously , r 1 , r 2 and r 3 may be alkyl or alkoxy groups having up to 12 carbon atoms . such alkoxy groups may be represented by the formula -- or 7 where r 7 defines the same class of alkyl substituents as r 1 , r 2 and r 3 , i . e . alkyl groups having 1 to 12 carbon atoms . preferably r 1 , r 2 , r 3 and r 7 have 1 to 4 carbon atoms . examples of r 1 , r 2 , r 3 and r 7 include methyl , ethyl , n - propyl , isopropyl , n - butyl , isobutyl , tert . butyl , straight or branched chain pentyl , straight or branched chain hexyl , straight or branched chain heptyl , straight or branched chain octyl , straight or branched chain nonyl , straight or branched decyl , straight or branched chain undecyl and straight or branched chain dodecyl . in forming the compounds of the present invention , the 1 , 4 - bis ( glycidoxymethyl ) cyclohexane compound may be reacted with methacrylic acid at a temperature of about 85 - 140 ° c . the reaction mixture may also contain a suitable electron donating catalyst such as triphenylphosphine and a polymerization inhibitor such as bht . more information on reactions of carboxylic acids with epoxides may be found in h . frankel - conrat and h . s . olcott , j . am . chem . soc . 66 , 1420 ( 1944 ). the adduct of methacrylic acid and 1 , 4 - bis ( glycidoxymethyl ) cyclohexane or ring substituted derivatives thereof is a dihydroxy compound , represented by the following formula : ## str20 ## this dihydroxy compound may then be converted to compounds of the present invention , e . g . mono - and / or dicarbamates of this dihydroxy compound , by reacting same with isocyanates of the formula where r 6 has the meaning defined above , i . e ., an aliphatic , aromatic or cycloaliphatic group having 1 to 14 carbon atoms , e . g . hydrocarbon groups or haloaryl groups such as chloroaryl groups . examples of groups represented by r 6 include methyl , ethyl , n - butyl , isoamyl , n - amyl , hexyl , n - octyl , isooctyl , dodecyl , tetradecyl , phenyl , p - ethyl benzyl , p - tolyl , p - butylphenyl , xylyl , α - napthyl , p - chlorophenyl , benzyl , cyclopentyl , m - chlorophenyl and cyclohexyl . a preferred group represented by r 6 is n - butyl . as hydrocarbon groups for r 6 there can be used for example , alkyl , aryl , aralkyl and cycloalkyl . reaction of the above - mentioned dihydroxy compound intermediate with various proportions of isocyanates may produce dicarbamates , monocarbamates or mixtures thereof . the dimethacrylates of the present invention may be combined with other polymerizable unsaturated materials , such as acrylic or methacrylic monomers or prepolymers , and polymerized . thus , the dimethacrylates of the present invention may be polymerized to form either homopolymers or copolymers , e . g ., containing at least 10 % by weight of these dimethacrylate moieties . preferably , copolymers of the dimethacrylates of the present invention may contain at least 40 % by weight of these dimethacrylate moieties , e . g ., wherein the moieties of the dimethacrylates of the present invention represent the predominate unit , e . g ., terpolymers containing 40 % of units compounds of the present invention and 30 % each of two other units . as used herein , the term &# 34 ; moiety &# 34 ; shall connote an entire repeating polymeric unit and not some lesser fragment thereof . polymers of the dimethacrylates of the present invention are characterized in that they may have a high degree of crosslinking . accordingly , these dimethacrylates may be added to mono - functional acrylic and methacrylic monomers and polymerized to form cross - linked polymers . example of these acrylic and methacrylic compounds include acrylic and methacrylic acid and esters thereof with alcohols containing , e . g ., 1 to 4 carbon atoms . examples of such acrylic and methacrylic esters include methylmethacrylate , ethylmethacrylate , butylmethacrylate , methylacrylate , ethylacrylate and butylacrylate . copolymers having an even higher degree of cross - linking may be produced by copolymerizing the dimethacrylates of the present invention with other polyfunctional acrylic ester or methacrylic ester monomers , i . e ., monomers containing two or more acrylic or methacrylic functionalities . one class of these polyfunctional monomers includes monomers which are used as diluents in dental materials . such polyfunctional acrylic ester or methacrylic ester monomers include alkylene glycol diacrylates , alkylene glycol dimethacrylates , polyalkylene glycol diacrylates , polyalkylene glycol dimethacrylates , alkanetriol triacrylates and alkanetriol trimethacrylates , e . g ., containing from 8 to 18 carbon atoms . examples of such monomers include ethylene glycol dimethacrylate , di -, tri - or tetraethylene glycol dimethacrylate , 1 , 6 - hexanediol dimethacrylate , the dimethacrylate formed by the reaction of methacrylic acid with butanediol , trimethylolpropane trimethacrylate and the acrylic esters corresponding to these methacrylates , e . g . ethylene glycol diacrylate . as far as polyfunctional acrylates and methacrylates are concerned , these monomers are characterized by relatively low molecular weight ( e . g ., 339 or less ) and low viscosity . the above - mentioned polyglycol dimethacrylates are further characterized by low surface tension . another class of polyfunctional acrylates and methacrylates includes the relatively high molecular weight ( e . g ., 364 or more ) acrylic or methacrylic monomers used in dental compositions . such polyfunctional compounds include , especially , dimethacrylates such as 2 , 2 - bis [ 4 &# 39 ;( 3 &# 34 ;- methacroyl - 2 &# 34 ;- hydroxypropoxy ) phenyl ] propane ( i . e . bis - gma ), 2 , 2 - bis [ 4 &# 39 ;( 2 &# 34 ;- methacroylethoxy ) phenyl ] propane ( i . e ., eba ), 2 - methacroylethyl - 3 - methacroyl - 2 - hydroxypropyl tetrahydrophthalate , 2 - methacroylethyl - 3 - methacroyl - 2 - hydroxypropyl hexahydrophthalate and 2 , 2 - bis ( 4 &# 39 ;- methacroylphenyl ) propane ( i . e . badm ). further polyfunctional monomers containing up to four acrylic or methacrylic functionalities are described in the stoffey et al u . s . pat . no . 3 , 721 , 644 , the entire disclosure of which is hereby incorporated by reference and relied upon . accordingly , copolymers may be formed from polymerizable materials comprising at least one dimethacrylate of the present invention and , e . g ., at least 10 % by weight of one or more of the copolymerizable materials described herein . polymerization of the dimethacrylates of the present invention may be initiated by known means for initiating the polymerization of dimethacrylates such as heat , chemical means or electromagnetic irradiation . thus , in order to induce curing of dimethacrylates , a free - radical catalyst may be incorporated therein . organic peroxide initiators , such as methyl ethyl ketone peroxide , t - butyl peroctoate , iso - propyl percarbonate , cumene hydroperoxide , dicumyl peroxide , and especially benzoyl peroxide , are preferred . the ability of the initiator to cure dimethacrylates may be enhanced through the use of activators or accelerators . thus , a peroxide initiator can be activated with a tertiary aromatic amine such as n , n - dimethyl - p - toluidine or n , n - bis ( 2 - hydroxyethyl )- p - toluidine . the amount of free - radical catalyst may be selected according to the curing rate desired . for instance , if a relatively slow curing rate is desired , a minimum catalytically effective amount , such as 0 . 5 % by weight based on the polymerizable components , may be selected . on the other hand , when faster rates of cure are desired , greater amounts of free - radical catalyst , such as 4 . 0 % or more by weight based on the polymerizable components , may be selected . accordingly , the amount of catalyst may range from about 0 . 5 to about 4 . 0 % by weight based upon the weight of the polymerizable components . as with the free - radical catalyst , the amount of the activator selected may vary , e . g ., from about 0 . 5 to about 4 . 0 % by weight of the polymerizable components , depending upon the desired curing rate . polymerization of the dimethacrylates of the present invention may also be initiated by ultraviolet or visible light using known light activated polymerization initiators such as benzoin , benzoin methyl ether , benzil and other commercially available photoinitiators . for example , one may select from about 0 . 5 % to about 5 % by weight based on the polymerizable components of a sensitizer capable of initiating polymerization when exposed to uv light between about 3550 a . to about 3720 a . the various components of a material containing a dimethacrylate of the present invention may be combined in any suitable manner . however , since chemically initiated polymerization starts immediately upon admixture of all three of ( 1 ) a methacrylate , ( 2 ) an initiator and ( 3 ) an activator , it is necessary to separate at least one of these components from the others until immediately before polymerization of the methacrylate . this separation may be achieved through the use of a two - package product , wherein various components of a material containing a dimethacrylate of the present invention are separately contained until the time of polymerization . therefore , the components of such a composition may be separated by means of a two - package product into two parts , one part containing the polymerization initiator and the other part containing the polymerization accelerator . it is helpful to package polymerizable methacrylates with inhibitors , such as butylated hydroxytoluene ( bht ) or hydroquinone methyl ether . thus , bht may be included in an amount from about 0 . 1 to about 0 . 3 % by weight based on the polymerizable components to increase the storage stability of these polymerizable components . ultraviolet stabilizers such as 2 - hydroxy - 4 - methoxybenzophenone ( cyasorb uv - 9 , a tradename of american cyanamide ) may be included to enhance the stability of the polymerizable components as well as polymers resulting therefrom . for example , from about 0 . 4 to about 1 . 6 % by weight of cyasorb uv - 9 based on the weight of the polymerizable components may be used for this purpose . in addition to polymerizable unsaturated material , inorganic or polymeric fillers may also be added to the monomers of the present invention prior to polymerization of these monomers . accordingly , the term &# 34 ; polymer &# 34 ; as used herein may connote a polymeric matrix material which binds together various fillers . up to about 6 . 5 parts of filler material per part of polymerizable unsaturated material may be included . particular inorganic filler materials include silica materials ( e . g ., powdered quartz , barium glasses , borosilicate glasses , sio 2 , fumed silica and lithium aluminum silicate ) and alumina materials ( e . g ., al 2 o 3 ). these inorganic filler materials may be treated with coupling agents , such as [ 3 -( methacroyl ) propyl ] trimethoxysilane , in order to assure the proper incorporation of filler into the polymeric matrix of the cured product . other materials such as pigments may also be included in polymerizable materials comprising the dimethacrylates of the present invention . it is noted that by varying the nature and proportions of curable compositions comprising one or more dimethacrylates of the present invention , a variety of such curable compositions as well as a variety of cured compositions resulting therefrom may be obtained . for example , curable compositions containing a relatively large amount of fillers , and relatively small amounts of low viscosity acrylic or methacrylic diluents , as well as minimum amounts catalysts and activators , may have a thick , doughlike consistency and a slow curing rate permitting working of the composition by molding and shaping before setting occurs . on the other hand , compositions containing little or no filler and relatively large amounts of low viscosity diluents , catalysts and accelerators may be flowable and fast curing , permitting brush - on application where little or no molding or shaping is required . polymerizable materials containing dimethacrylates of the present invention may now be described by way of examples of various dental materials . in this regard , composite restorative materials are given particular emphasis . composite restorative materials , as the name implies , is a composite material of a polymerizable material and a suitable filler . these materials are capable of curing in situ on teeth to restore a hardened surface thereto . these materials are generally applied as a filling material to prepared or drilled teeth . accordingly , composite restorative materials should be of a thick , workable consistency suitable for application to a prepared tooth and capable of being shaped or molded thereon before setting occurs . thus , composite restorative materials are relatively slow curing . the thick consistency of composite restorative materials , as well as the desirable properties of the cured product formed from these materials , are largely a function of the relatively large amounts of filler materials employed therein . more particularly , composite restorative materials may contain glass or ceramic fillers in excess of the polymerizable material employed therein . when the polymerizable material of the composite restorative contains one or more dimethacrylate monomers of the present invention , the weight ratio of filler to polymerizable material may range from about 1 . 5 : 1 to about 6 . 5 : 1 and , most especially , from about 4 : 1 to about 6 : 1 . suitable ceramic or glass fillers include silica materials , such as powdered quartz , barium glasses , borosilicate glasses , sio 2 and lithium aluminum silicate , and alumina materials , such as al 2 o 3 . since composite restorative materials must be capable of conforming to the confined space of prepared tooth and hardening therein to achieve restoratuve properties , the particle size of these fillers must be sufficiently small . generally , the particle sizes of these fillers may range from about 1 to about 150 microns , preferably from about 1 to about 40 microns . the average particle size of these fillers is preferably less than about 25 microns . suitably , composite restorative materials may contain a mixture of two or more fillers , such as a mixture of a ceramic filler ( e . g . powdered quartz ) and glass filler ( e . g ., powdered glass ). according to techniques well known in the art , the fillers of composite restorative materials may be treated with one or more organosilane coupling agents . these coupling agents are also sometimes referred to as finishing or keying agents and include materials such as [ 3 -( methacroyl ) propyl ] trimethoxysilane . a sufficient coupling amount of such coupling agent may be a small amount such as from about 0 . 5 to about 1 . 0 part of coupling agent per 100 parts of filler . methods for treating fillers with coupling agents are described , for example , in u . s . pat . no . 3 , 066 , 112 ( bowen ), wherein an aqueous solution of tris ( 2 - methoxyethoxy ) vinyl silane is catalyzed with sodium hydroxide to give a ph of 9 . 3 to 9 . 8 , and the filler is treated with this solution , for example , one - half percent of silane per weight of fused quartz . a slurry so formed is dried at about 125 ° c . and cooled . another technique for treating filler with a coupling agent is described in the passage extending from column 3 , line 40 to column 4 , line 4 of u . s . pat . no . 3 , 862 , 920 ( foster et al ). as indicated previously , the filler , rather than polymerizable material , constitutes a major portion of the composite restorative material . perhaps for this reason the polymerizable material in composite restoratives is sometimes referred to as a &# 34 ; binder &# 34 ;. the polymerizable materials for forming a composite restorative material may contain at least two monomeric components , termed herein a first monomer and a second monomer . this first monomer is at least one dimethacrylate monomer according to the present invention , and the second monomer is at least one relatively low molecular weight diluent monomer which , among other purposes , serves to reduce the overall viscosity of the composite restorative materials . the first monomer of the polymerizable material may be present in an amount of from about 20 to about 90 % by weight , preferably from about 30 to about 80 % by weight , of the polymerizable material . the second monomer may be present in an amount from about 10 to about 80 %, preferably from about 20 to about 30 % by weight , of the polymerizable material . as a second monomer , an acrylic or methacrylic diluent , which is used for this purpose in dental materials , may be selected . more particularly , this diluent may be a di - or trimethacrylate having from 10 to 18 carbon atoms . diluents falling within this class of compounds include relatively low molecular weight ( e . g ., 339 or less ) alkylene glycol dimethacrylates , polyalkylene glycol dimethacrylates and alkanetriol trimethacrylates . particular examples of such diluents include di -, tri - or tetraethylene glycol dimethacrylate , 1 , 6 - hexanediol dimethacrylate , and trimethylolpropane trimethacrylate . triethylene glycol dimethacrylate is a preferred diluent . the polymerizable material of composite restoratives may also contain at least one third monomer . this third monomer may be a relatively high molecular weight ( e . g ., 364 or more ) polyfunctional acrylic or methacrylic monomer used in dental compositions . such polyfunctional compounds include dimethacrylates such as 2 , 2 - bis [ 4 &# 39 ;( 3 &# 34 ;- methacroyl - 2 &# 34 ;- hydroxypropoxy ) phenyl ] propane ( i . e . bis - gma ), 2 , 2 - bis [ 4 &# 39 ;( 2 &# 34 ;- methacroylethoxy ) phenyl ] propane ( i . e ., eba ), 2 - methacroylethyl - 3 - methoacroyl - 2 - hydroxypropyl tetrahydrophthalate , 2 - methacroylethyl - 3 - methacroyl - 2 - hydroxypropyl hexahydrophthalate and 2 , 2 - bis ( 4 &# 39 ;- methacroylphenyl ) propane ( i . e . badm ). although the third monomer constitutes a different class of materials than the first monomer , the first monomer and third monomer serve similar functions . therefore , the third monomer may be used as a replacement for a portion of the first monomer , provided that the polymerizable material contains at least 20 % by weight of the first monomer . this third monomer may be used in quantities close to the quantities of first monomer . for example , the weight ratio of the first monomer to the third monomer may range from about 3 : 5 to about 5 : 3 . accordingly , when the first monomer is present in an amount ranging from about 30 to about 50 % by weight of the polymerizable material , the third monomer may also be present in an amount ranging from about 30 to about 50 % by weight of the polymerizable material . preferably , however , the weight percent of the first monomer is greater or equal to the weight percent of the third monomer . in describing various composite restorative compositions , mention has been made of various specific compounds , such as triethylene glycol trimethacrylate and bis - gma , which fall into classes of compounds referred to as a second monomer or third monomer . however , it will be understood that the polymerizable material of the composite restorative material may contain further compounds which may fall within these categories of second or third monomers and / or may even fall in some separate and distinct category . for example , the polymerizable material may contain a small amount of methacrylic acid . however , due to the objectionable odor and properties of methacrylic acid , this monomer should not be present in quantities in excess of about 2 % by weight ( e . g ., between about 1 and 2 % by weight of the polymerizable material ). composite restorative compositions may be cured by any suitable means , a chemically initiated system being preferred . this initiating system involves the use of a catalyst and an accelerator . peroxide catalysts such as benzoyl peroxide and tertiary amine accelerators such as n , n - bis ( 2 - hydroxyethyl )- p - toluidine are preferred . the amounts of catalyst and accelerator may each be from about 0 . 5 to about 2 . 0 % by weight of the polymerizable materials . desirably , initial curing of the composite restorative material should take place in about 1 to about 2 minutes upon admixture of the components thereof in order to permit adequate mixing and manipulation of these components outside the mouth prior to application to a prepared tooth . however , final curing is desirably delayed for 4 to 6 minutes from the initial contacting of restorative components in order to permit proper molding and shaping inside the mouth . it is noted that template structures are sometimes used in this molding process . composite restorative materials having such curing characteristics may enable a dentist to perform a complete restoration of a prepared tooth within about ten minutes , including grinding and polishing the restorative material after final setting . composite restorative materials may be packaged in any suitable manner . preferably , a two - package system is used wherein each package contains filler and polymerizable material in roughly equal amounts , one package containing the catalyst and the other package containing the accelerator . however , other systems are also possible . for example , according to another two - package system , one package may contain both filler and catalyst and the other package may contain polymerizable material and accelerator . another system involves packaging together each of the components excluding the catalyst component . when this system is used , polymerization can be initiated by introducing catalyst dropwise from a stock solution thereof . such a stock solution is described in the taylor u . s . pat . no . 3 , 541 , 068 ( note particularly column 6 , lines 23 - 50 ). whatever packaging system is used , it is helpful to package polymerizable materials with one or more polymerization inhibitors such as bht in order to enhance storage life . also , shelf life of components containing accelerators may be improved by removing traces of peroxides from these components with a reducing agent . cured composite restoratives containing at least one monomer according to the present invention have desirable properties and may be capable of holding up under strong mastication forces . for instance , these materials may have a water sorption at 37 ° c . of 0 . 5 mg / cm 2 or less ( preferably 0 . 42 mg / cm 2 or less ), a compressive strength of 40 , 000 psi or more ( preferably 42 , 000 psi or more ); a diametral tensile strength of greater than 5 , 000 psi ( preferably 6 , 000 psi or more ), a hardness ( barcol ) of greater than 98 ( preferably 100 or more ), and a linear shrinkage of 0 . 4 % or less ( preferably 0 . 38 % or less ). while particular emphasis has been devoted herein to the use of the monomers of the present invention in composite restorative materials , it will be understood that these monomers may also be used in other dental materials . examples of these other dental materials are given in the waller u . s . pat . no . 3 , 629 , 187 ( note particularly column 11 , line 26 to column 15 , line 36 ) and in the kirk - othmer encyclopedia of chemical technology , third edition , volume 7 ( 1979 ), pages 501 - 508 and 515 - 517 . waller characterizes these materials as , e . g ., dental cements , dental cavity liners and dental lacquers . kirk - othmer characterizes these materials as , e . g ., unfilled tooth - restorative resins , pit and fissure sealants and adhesives . in addition to one or more monomers according to the present invention , dental materials may contain one or more of the copolymerizable materials described herein , provided that such copolymerizable material is acceptable for oral application associated with dental treatment . particular examples of such copolymerizable material include those methacrylate monomers mentioned herein with respect to composite restorative materials . the fillers described herein with respect to composite restorative materials may also be used in certain other dental materials . certain dental materials may contain various amounts of filler , while other dental materials contain no filler at all . for instance , the dental cements described in the waller u . s . pat . no . 3 , 629 , 187 may contain little or no filler if a transparent cement is desired , but these cements may contain up to about a 1 : 1 ratio of filler to polymerizable material if a translucent cement is acceptable . it is noted that fillers used in dental cements generally have smaller particle sizes ( e . g ., an average particle size of 10 microns or less ) with respect to fillers used in composite restorative materials . an example of a dental material containing no filler may be characterized as a fissure sealer or as a bonding agent for use as an under coating for a composite restorative or orthodontic adhesive . such a material may comprise polymerizable material comprising 65 - 75 % by weight of at least one dimethacrylate of the present invention and 35 - 45 % by weight of a suitable diluent such as triethylene glycol trimethacrylate . such a material may be rapidly curable and capable of brush - on application . these sealers or bonding agents may cure to form a semi - translucent polymer having a barcol hardness of 80 or more . the bonding strength to phosphoric acid etched human enamel may be from 1100 - 1200 psi . an example of a dental material containing a relatively small amount of filler is an orthodontic adhesive containing as a polymerizable material 50 - 60 % by weight of the dimethacrylate of the present invention and 40 - 50 % by weight of a suitable diluent such as diethylene glycol dimethacrylate . the filler , e . g ., fumed silica , may comprise 10 - 15 % by weight of the sum of the combined weights of polymerizable material plus filler . the bonding strength of such an adhesive to etched human enamel may be 1200 - 1300 psi and the bonding strength to mesh - type orthodontic bracket bases may be 14 - 40 pounds depending on bracket size and individual design of the bracket bases . dental materials may be cured by a photoinitiation technique using known light polymerization initiators or by chemically initiated systems including those systems using sulfonic acid activators . in addition to fillers and polymerizable material , dental materials may contain other substances . for instance , pigments may be included . also , ultraviolet absorbers or stabilizers may be included to lessen discoloration of the cured material . furthermore , fluorides , bacteriostatic agents and antibiotics may also be included . dental materials may be applied to teeth in a variety of manners depending upon the nature of the material and the desired use . for instance , thick , slow - curing materials , such as composite restoratives , may be molded and shaped in the mouth before final curing takes place . on the other hand , flowable , fast - curing materials , such as cavity liners may be simply brushed on the surface of the treated tooth . dental materials such as restoratives , sealers , bonding agents , cements and orthodontic adhesives containing in their resin part 20 - 90 % of the dimethacrylate of the present invention exhibit most desirable properties , especially in respect to color stability , low water absorption , high mechanical strength and low polymerization shrinkage . the following examples describe certain embodiments of the invention . it is to be understood that these examples are given only to illustrate the nature of the invention and should not , in any way , be understood as limiting the scope of this invention , defined in the claims . were placed in a round bottom reaction flask equipped with a condenser , heater and mechanical stirrer . the mixture was heated up to 100 ° c . and maintained at this temperature while stirring until the epoxy equivalent reached a value of 0 . 012 or below . the excess of methacrylic acid was then distilled off . the reaction product , called decd , consists of a medium viscosity liquid having a refractive index n d 25 1 . 487 . 460 g of decd was placed in a round bottom flask to which 300 ml of ethyl ether was added . the ether was then distilled off in a gentle stream of dry air in order to remove any traces of water . 170 g of butyl isocyanate was added slowly with stirring over a period of 1 hour while maintaining temperature of the reaction mixture at 45 ° c . this temperature and stirring was maintained for 10 hours after which the reaction mixture was allowed to stand overnight at room temperature of 23 °- 27 ° c . the reaction product constitutes a light yellow colored viscous liquid and represents a mixture of n - butyl mono - and di - carbamates of 1 , 4bis [( 3 &# 39 ;- methacroyl - 2 &# 39 ;- hydroxypropoxy ) methyl ] cyclohexame called hereafter deci . a dental material for use as a fissure sealer or as a bonding agent to be used under composite restorative or orthodontic adhesives has been formulated as follows : ______________________________________part a part b ( parts by weight ) ( parts by weight ) ______________________________________57 deci 5738 . 5 diethyleneglycol dimeth - 40 acrylate0 . 1 bht 0 . 10 . 4 cyasorb uv - 9 0 . 44 . 5 n , n -- bis ( 2 - hydroxy - -- ethyl )- p - toluidine -- benzoyl peroxide 2 . 5______________________________________ parts a and b when mixed in equal amounts cured in 120 seconds forming a semi - translucent polymer having a barcol hardness of 80 . the adhesive bond strength to phosphoric acid etched human enamel was 1100 - 1200 psi . color stability in sunlight was excellent . a dental composite restorative for use as a filling material in anterior and posterior restorations has been formulated as follows : ______________________________________part a part b ( parts by weight ) ( parts by weight ) ______________________________________38 deci 3826 triethyleneglycol dimeth - 26 acrylate31 bis - gma 31 . 90 . 9 cyasorb uv - 9 -- 0 . 1 bht 0 . 14 n , n bis ( 2 - hydroxy - -- ethyl )- p - toluidine -- benzoyl peroxide 4500 5 : 1 mixture of pow - 500 dered barium and boro - silicate glasses below 44 microns , treated with meth - acroylpropyl trihydroxy - silane______________________________________ parts a and b when mixed in equal amounts cured in 120 seconds . the resulting material had the following characteristics : ______________________________________part a part b ( parts by weight ) ( parts by weight ) ______________________________________44 deci 4438 . 4 diethyleneglycol dimeth - 39 acrylate . 6 cyasorb uv - 9 -- 4 n , n -- bis ( 2 - hydroxyethyl )- -- p - toluidine -- benzoyl peroxide 413 fumed silica 13______________________________________ this adhesive cured in 60 seconds , when parts a and b were mixed to equal amounts . bonding strength to etched human enamel was 1200 - 1300 psi and bonding strength to mesh - type orthodontic bracket bases was 14 - 40 pounds depending on bracket size and individual design of the bracket bases . while the use of the monomers of the present invention has been described primarily with respect to dental materials , particularly composite restorative materials , it is noted that these monomers may also be used in other materials such as bone cements and uv curable inks . thus while certain representative embodiments and details have been shown for the purposes of illustrating the invention , it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit or scope of the invention . it will further be understood that the invention may comprise , consist essentially of or consist of the steps or materials recited herein .
dimethacrylates are provided having the following chemical structure : ## str1 ## where ## str2 ## is a saturated , 6 membered , monocyclic , hydrocarbyl ring system ; r 1 , r 2 and r 3 are the same or different and are hydrogen or alkyl or alkoxy groups having 1 to 12 carbon atoms ; and r 4 and r 5 are the same or different and are hydrogen or groups of the formula : ## str3 ## where r 6 is an aliphatic , aromatic or cycloaliphatic group having 1 to 14 carbon atoms , provided that at least one of the groups r 4 and r 5 is a group of the formula : ## str4 ## these compounds are useful in dental material which cures to form polymers having high mechanical strength , low water sorption , resistance to staining , good color stability when exposed to short - wave radiation and good chemical resistance to the oral environment . also provided are a method for polymerizing this compound in situ on teeth and a tooth comprising a polymer of this compound .