CA2265756C - Floor finish compositions - Google Patents

Abstract

A monomer useful in the formulation of a radiation curable coatable composition comprises (a) polyfunctional isocyanurate having at least three terminal reactive groups reacted with (b) hydroxyalkyl acrylate and (c) tertiary amine alcohol in a molar ratio of a:b:c of about 1:1-2.5:0.5-2, wherein b + c is at least 3 and no greater than the total number of terminal reactive groups of (a). The monomer is included in a radiation curable coatable composition suitable for use as a floor finish and in a floor finishing system comprising the foregoing coatable composition with a primer. A method for the treatment of a substrate using the floor finish and the floor finishing system is also described.

Description

1015202530W0 98/11168CA 02265756 l999-03- l2PCT/US96/14666FLOOR FINISH COMPOSITIONSThe present invention relates to a radiation curable coatable compositionsuitable for use as a floor finish, to a floor finishing system utilizing thecomposition, to a method for applying a protective coating to a substrate, tosubstrates coated with the compositions and to a polyfunctional isocyanuratemonomer useful in the formulation of the radiation curable coatable compositions.Background of the InventionPolymer compositions are used in the formulation of various coatingcompositions such as floor finishes, for example. Commercially available floorfinish compositions typically are aqueous emulsion based polymer compositionscomprising one or more organic solvents, plasticizers, coating aids, antifoamingagents, polymer emulsions, waxes and the like. These compositions typicallycomprise a relatively low solids content (e.g., about 15 - 35%). The polymercomposition is applied to a floor surface and then allowed to dry in air, normally atambient temperature and humidity to form a film that serves as a protective barrieragainst soil deposited on the floor by pedestrian traffic, for example. _Although many of the commercially available floor finishes have performedwell and have experienced at_least some commercial success, the available finisheshave been less than completely satisfactory for several reasons. For example, whenapplying conventional floor finish compositions to the surface of a floor, severalcoating applications are typically required to obtain a finish with a suitableappearance. Each successive application of the composition must be dried beforeadditional coatings are applied and/or before pedestrian trafiic is allowed across thetreated floor. The compositions are normally dried at ambient temperature andhumidity in air, so that the drying time depends upon the air flow over the floor aswell as the relative humidity of the air. Conventional floor finishes will soften whenexposed to water for short periods or when exposed to strong chemical cleanersduring a scrubbing operation, for example. Moreover, such finishes require almostdaily maintenance (e.g., buffing) to provide a sustained and desirable appearance.1015202530W0 98/11168CA 02265756 l999-03- l2PCTIUS96/14666In light of the foregoing, it is desirable to provide a floor finish compositionthat can be applied in a single application and immediately dried and hardened in airto provide a durable, low maintenance, water-resistant, chemically resistant finishthat does not require labor intensive (e.g., daily) maintenance to provide a sustainedand desirable appearance. It would also be desirable to provide such a durable, lowmaintenance, water-resistant, chemically resistant finish in a form that can readily beremoved from the surface to which it is applied, such as from flooring comprisingconventional vinyl floor tiles, for example.It is known that irradiation of ethylenically unsaturated compounds in thepresence of a photoinitiator induces photopolymerization. As used herein,“photoinitiator” refers to any substance or combination of substances that interactwith light to generate free radicals capable of inducing free radical polymerization.Photochemical or photoinitiated free radical polymerizations occur when radicalsare produced by ultraviolet (“UV”) and/or visible light irradiation of a free radicalpolymerizable reaction system. Energy absorption by one or more compounds inthe system results in the formation of excited species, followed by either subsequentdecomposition of the excited species into radicals or interaction of the excitedspecies with a second compound to form radicals derived from both the initiallyexcited compound and from the second compound. The exact mechanism forphotoinitiation is not always clear and may involve either or both of theaforementioned pathways.Photochemical polymerization has been applied in the formation ofdecorative and/or protective coatings and inks for metal, paper, wood and plasticsas well as in photolithography for producing integrated and printed circuits and incuring dental materials. Many of the known applications involve a combination ofphotopolymerization and crosslinlcing with the crosslinking typically achieved by theused of ethylenically polyunsaturated monomers. Acrylate based systems arecommon as well as those based on unsaturated polyester and styrene.Additionally, UV curable protective finishes have been applied to vinyl “nowax” flooring during the sheet manufacturing process to provide gloss as well asabrasion resistance. These protective finishes generally carmot be easily stripped1015202530W0 98/1 1168CA 02265756 l999-03- l2PCTIU S96/ 14666from the flooring to which they are applied using conventional stripping methods(e.g., by the application of a chemical stripping composition with a stripping pad orbrush). Furthermore, the curing of these finishes is typically carried out using highintensity light. The lamps have high power requirements, large power supplies andgenerally require ducted venting to remove ozone. Ofien, these finishes are curedin an inert atmosphere to overcome the deleterious effects of oxygen on the curingprocess. Because of the above noted power requirements and the like, the use ofUV curable polymeric systems in the treatment of flooring has generally beenlimited to factory scale processes where the expense and additional burdensassociated with these systems is more easily justified.Other problems have been noted in the fomiulation of UV curable systemsfor pre-existing flooring (e.g., previously installed in a building). In the applicationof any type of finish to an existing floor, it is generally preferred that the hardened 'floor finish not alter the color of the floor. To accomplish this goal, the finishshould be transparent and substantially free of observable color. This goal isespecially desired in the maintenance of floors composed of white floor tiles wherean observable color in the hardened finish will more noticeably produce anobservable discoloration in the floor. Additionally, to make a floor finishcomposition acceptable for application in the field, the applied floor finish shouldalso have low odor prior to curing.It is known, for example, that certain resins containing fimctionalpolymerizable vinyl groups, such as acrylate or vinyl ether/maleate containing anamine or a thiol, are polymerizable in air by fi'ee radical polymerization whenexposed to UV or visible light in the presence of a photoinitiator. Although tough,abrasion resistant coatings can be provided using such resins, the resulting coatingsare typically colored, with colors ranging from yellow to dark orange or have anobjectionable odor prior to curing. Consequently, these resins are consideredunsuitable for use as floor finishes.As mentioned, atmospheric oxygen is known to inhibit photoinitiatedpolymerization reactions, resulting in little or no cure on the surface of the coatingor providing a coating with poor surface properties. Various processing techniques1015202530W0 98/11168CA 02265756 l999-03- l2PCT/U S96/ 14666have been proposed to eliminate the effects of oxygen from the reacting resin. Oneapproach is to isolate the coating in a chamber and purge the chamber with an inertgas (e.g., nitrogen) so that the polymerization reaction proceeds in an environmentsubstantially free of oxygen. Another approach is to initiate the polymerizationreaction using intense UV radiation in conjunction with the high levels ofphotoinitiator in the uncured resin. Neither of these proposed techniques arepractical in providing a floor finish system for use on previously installed flooring.Although smaller, lightweight, inexpensive, low intensity light sources capable ofoperating on batteries or on 110 volt, 15 amp circuitry would be preferred, knownUV curable polymer systems have experienced slower rates of cure and higher cureinhibition when low intensity light has been used.A long felt and unsolved need exists for a coatable composition suitable foruse as a floor finish that can easily be applied to a substrate, such as a previouslyinstalled floor, and hardened in air upon exposure to low intensity radiation such asultraviolet light, for example. It is desirable to provide such a coatable composition,preferably without objectionable odor, in a form that may be easily applied to afloor and subsequently hardened to provide a protective coating substantially free ofobservable color. It is also desirable to provide the foregoing protective coatings ina form that allows them to be removed from the floor (e.g., by a suitable chemicalstripper), as desired.Summar_'y of the Invention AThe invention provides a coatable composition that can be cured quickly inair by exposure to low intensity ultraviolet radiation to provide a durable protectivecoating for a suitable substrate such as vinyl floor tile, for example. The resultingcoating requires little maintenance and can be easily and quickly stripped from thesubstrate by application of a suitable stripper composition, all as set forth herein.In one aspect, the invention provides a monomer usefiil in the formulation ofradiation curable coatable compositions, comprising (a) polyfimctional isocyanuratehaving at least three terminal reactive groups reacted with (b) hydroxyalkyl acrylateand (c) tertiary amine alcohol in a molar ratio of azbzc of about 1:1-2.S:O.5-2,10152025CA 02265756 l999-03- 12W0 98/11 168 PCTIUS96/14666wherein b + c is at least 3 and no greater than the total number of terminal reactivegroups of (a).A preferred monomer comprises a compound having the general formula:H2c=cR2co—z,«,—ocNH—z5\N/fi\N,z1——NH— C-0—Z2-0CCR1=CH2goIfaR3NH o—z4-N’E sm0whereinR1 and R2 are H or CH3;R3 and R4 may independently be alkyl groups (straight, branched orcyclic) having fi'om 1 to 12 carbon atoms, or R3 and R4 maytogether fonn a divalent cylcoalkanediyl, oxacycloalkanediyl,or azacycloalkanediyl bridging group having from 2 to 12carbon atoms; andZ1, Z2, Z3, Z4, Z5, and Z5 independently represent divalent groups" having from 1 to 18 carbon atoms, preferably alkanediylgroups (straight, branched or cyclic) having from 1 to 18carbon atoms, most preferably, straight chain alkanediylgroups having from 1 to 4 carbon atoms.The foregoing monomer is formulated into radiation curable coatablecompositions as a first monomer by combining it with a second monomer andphotoinitiator. The first monomer preferably comprises the reaction product of atrimer of hexane diisocyanate (optionally mixed with an allophanate of hexanediisocyanate), a hydroxyalkyl acrylate, and a tertiary amine alcohol. The firstmonomer is typically present within the composition in an amount between about10 and 80 wt%. The second monomer can be selected from any of a variety ofpolymerizable monomers. Preferably, the second monomer is an acrylate, as isfiirther described herein. The second monomer is typically present within the1015202530W0 98/11168CA 02265756 l999-03- l2PCT/US96/ 14666composition in an amount between about 5 and 90 wt%. In addition to the secondmonomer, the composition may fiirther comprise additional polymerizablemonomers, including combinations of two or more such monomers. A suitablephotoinitiator is included within the composition to facilitate curing by UVradiation. Preferred are those initiators suitable in the formation of clear coatingshaving a low degree of observable color. Photoinitiator concentrations within thecomposition may vary depending on the nature of the other components of thecomposition and the nature of the photoinitiator. A typical concentration for thephotoinitiator is between about 2 and 10% by weight.Certain terms will be understood to have certain meanings, as set forthherein. “Ultraviolet radiation” and “UV radiation” are used interchangeably to referto the spectrum of light comprising wavelengths within the range from about 180nm to 400 nm. “Coatable composition” means a liquid composition that can beapplied to a substrate and thereafter solidified (e. g., by UV curing) to form ahardened coating on the substrate. “Radiation curable”, in referring to the coatablecompositions, means that the coatable composition will form a hardened coatingupon exposure to radiation such as UV radiation or visible light (e. g., 180 to 800nm). “Substrate” refers to any surface upon which the coatable compositions of theinvention are applied and includes without limitation, vinyl floor tiles (including tilespreviously coated with floor sealer or the like), ceramic tiles, wood, marble, and thelike. As used herein, “acrylate” will be understood to include acrylate andmethacrylate species. “Monomer” refers to any chemical species having at least onefree radical polymerizable group (e. g., acrylate, methacrylate). “Tertiary aminealcohol” is meant to indicate a tertiary amine that includes alcohol functionality.In another aspect, the invention provides a floor finishing system,comprising the radiation curable coatable composition described above and a primercomposition, the primer composition coatable over a substrate. In this aspect of theinvention, the coatable composition is as previously described. The primerpreferably comprises an acrylated latex with a solids content in water between about2 and about 40% by weight. The latex is applied to the substrate and dried prior tothe application of the coatable composition. The primer provides a layer over the1015202530W0 98/11168CA 02265756 l999-03- 12PCT/U S96/ 14666substrate to which the coatable composition may bond. Moreover, the curedcoatable composition is readily strippable from the substrate when the latex primeris present.In still another aspect of the invention, a method for applying a protectivecoating to a substrate, comprising:(A) applying a radiation curable coatable composition to a substrate, thecomposition comprising:(i) a first monomer comprising (a) polyfunctional isocyanurate having atleast three terminal reactive groups reacted with (b) hydroxyalkyl acrylateand (c) tertiary amine alcohol in a molar ratio of azbzc of about 1:1-2.5:0.5-2, wherein b + c is at least 3 and no greater than the total number of terminalreactive groups of (a),(ii) a second monomer, and(iii) photoinitiator; and(B) hardening the composition to form a protective coating over the substrateby exposing the coatable composition to ultraviolet radiation.In this aspect of the invention, the first monomer, the second monomer andthe photoinitiator are as previously described. Overall, the coatable composition ispreferably comprises at least about 90% solids (e.g., less than about 10% solvent).Hardening of the composition in step (B) may be achieved in air at prevailingtemperature and humidity (e. g., at ambient conditions). Although high intensityradiation achieves faster curing of the coatable composition and is generallypreferred in performing the hardening step (B), the coatable compositions can alsobe cured with low intensity UV radiation. Hardening of the coatable compositionsat low UV intensities can be accomplished fairly quickly (e.g., less than 30 seconds)using a low intensity radiation source that provides at least one band of wavelengthsless than about 300 nm and a second band between about 300 and 400 nm.Preferably, such a low intensity radiation source emits a first band of wavelengthscentered around 254 nm and a second band centered between 350 and 370 nm (e.g.,around 365 nm) to cure the coating (typically about 0.03 mm thick) in less thanabout 30 seconds. A suitable low intensity radiation source is one that provides a1015202530WO 98111168CA 02265756 l999-03- l2PCT/US96l14666radiation intensity between about 5 and 15 mW per square centimeter. Preferably,the exposure of the coating to the low intensity radiation is for a period of up toabout 30 seconds.The foregoing method may also comprise, prior to the foregoing applyingstep (A), applying a primer composition to the floor and drying the primercomposition to form a primer coat over the substrate. As discussed above, thepreferred primer composition is an acrylated latex, preferably having a solidscontent between about 2 and about 40% by weight.In still another aspect, the invention provides a coating derived from theforegoing radiation curable coatable composition. In another aspect, the inventionprovides a substrate coated with the aforementioned coating.In still another aspect, the invention broadly provides a method for applyinga protective coating to a substrate, comprising:(a) applying a coatable acrylated latex primer composition to thesubstrate;(b) drying the primer composition to fonn an acrylated polymer primercoat over the substrate;(c) applying a radiation curable coatable composition to the primercoat; and(d) hardening the radiation curable coatable composition by exposingthe composition to ultraviolet radiation to form a protective coatingover the substrate.The details of the invention will be more fiilly appreciated by those skilled inthe art upon consideration of the remainder of the disclosure including the detaileddescription of the preferred embodiment and the appended claims.Detailed Description of the Preferred EmbodimentThe preferred embodiment of the invention will now be described. It will beappreciated that the preferred embodiment, while illustrative, is not to be construedas unduly limiting the scope of the invention.Coatable compositions according to the invention are formulated with a firstmonomer comprising anisocyanurate. The preferred first monomer is derived froml015202530W0 98/11168CA 02265756 l999-03- 12PCT/U S96/ 14666the reaction of a polyfunctional isocyanate, hydroxyalkyl acrylate and tertiary aminealcohol. The compositions of the invention also comprise a second monomer andphotoinitiator.The individual components used in the formulation of the coatablecomposition will now be described.FIR T MON RIn the formulation of radiation curable coatable compositions usable as floorfinishes, it is desired that the end product (e.g., the final hardened coating) besubstantially free of observable color, provide a hard and durable finish, and bereadily removable from the substrate to which the composition has been applied.To this end, it has been found that compositions comprising a certain class ofpolyfunctional isocyanurates will provide the desired coating.The first monomer is preferably prepared from the reaction of polyfimctionalisocyanurate, (hydroxyalkyl)dialkylarnine, and a hydroxyalkyl acrylate. In thereaction, about one mole of polyfunctional isocyanurate is reacted with from aboutone to about 2.5 moles of the hydroxyalkyl acrylate and with from about 0.5 toabout 2.0 moles of the tertiary amine alcohol. As a result of the forgoingpreparation, the first monomer comprises (a) polyfunctional isocyanurate havingabout three terminal reactive groups reacted with (b) hydroxyalkyl acrylate and (c)tertiary amine alcohol in a molar ratio of a:b:c of about 1:1—2.5:0.5—2, wherein b + cis at least 3 and no greater than the total number of terminal reactive groups of (a).The terminal reactive groups of the polyfunctional isocyanurate comprise isocyanategroups (-NCO), each of which is capable of reacting with the hydroxyl groups inboth the hydroxyalkyl acrylate and the tertiary amine to form a urethane linkage (-NH-C0-O-) within the reaction product. Although the theoretical functionality ofthe polyfunctional isocyanurate is three, it will be appreciated the actualfimctionality of the polyfunctional isocyanurate may be somewhat less (e. g. between2.5 and 3.0) while still being within the scope of the present invention.As a result of the foregoing reaction , the first monomer may comprise acompound having the general formula:10152025CA 02265756 l999-03- 12WO 98/11168 PCT/US96/14.666H2C=CR2CO""Z6—OCNH'-Z5\NKN/Z1-NH"— C—0"Z2—OCCR1=CH2*0I3R3NH o—z.—N’F, em0R1 and R2 are H or CH3;R3 and R4 may independently be alkyl groups (straight, branched orcyclic) having from 1 to 12 carbon atoms, or R3 and R4 maytogether form a divalent cylcoalkanediyl, oxacycloalkanediyl,or azacycloalkanediyl bridging group having from 2 to 12carbon atoms; andZ1, Z2, Z3, Z4, Z5, and Z5 independently represent divalent groupshaving from 1 to 18 carbon atoms, preferably alkanediylgroups (straight, branched or cyclic) having from 1 to 18carbon atoms, most preferably, straight chain alkanediylgroups having from 1 to 4 carbon atoms;The polyfimctional isocyanate trimer useful in the formation of thepolyfunctional isocyanurate preferably is a low viscosity polyfunctional aliphaticpolyisocyanate resin. Preferably, the polyfunctional isocyanurate is a trimer ofaliphatic diisocyanate and more preferably is a trimer derived from hexamethylenediisocyanate (HDI). In formulating the first monomer, it has been found that theforegoing polyfimctional isocyanurate is important in the formation of clear andsubstantially colorless coatings by UV curing. Moreover, compositions based onthese polyfunctional isocyanurates typically cure rapidly (e.g., less than a minute) inair upon exposure to low intensity UV light.Suitable polyfunctional isocyanurate may readily be synthesized by theoligomerization of diisocyanate (e.g., HDI) to provide the foregoing trimer, as isknown to those skilled in the art. Suitable products based on HDI derivedisocyanurate are commercially available such as those available under the trade101015202530WO 98/11168CA 02265756 l999-03- l2PCT/US96/14666designation DESMODUR N—3300. In addition, allophanated trimers derived fiomthe reaction of HDI and butanol are suitable for use in the invention and arecommercially available under the trade designations DESMODUR XP 7100 andDESMODUR XP 7040. The abovementioned isocyanate trimers are available fromthe Industrial Chemicals Division of Bayer Corporation, Pittsburgh, Pennsylvania.It is preferred that the amount of allophanate be minimized for better performanceof the resulting cured coating. Low viscosity aliphatic isocyanate diluents may beused in a similar manner, subject to the same requirements. To provide a preferredcombination of performance characteristics in the finished coating and reducedviscosity in the coatable composition, the DESMODUR XP 7100 monomer is mostpreferred.The polyfimctional isocyanurate used herein provides three distinct reactiveisocyanate groups extending from the isocyanurate ring. Each of the isocyanatefunctionalities is capable of reacting with the hydroxyl group on both the tertiaryamine alcohol and the hydroxyalkyl acrylate to form the first monomer.Tertiary amine alcohols suitable for use in the invention include acyclic(hydroxyalkyl)dialkylamines having from 3 to 30 carbon atoms such as N,N-dimethylaminoethanol, N,N-dimethylaminopropanol, N,N-dimethylaminobutanol,N,N-dimethylaminohexanol, N,N-dimethylaminododecanol, N,N-diethylaminoethanol, N,N-diethylaminopropanol, N,N-diethylaminobutanol, N-ethy1-N-methylaminopropanol, N-ethyl-N-hexylaminoethanol, and the like; alicyclic(hydroxyalkyl)dialkylamines having from 3 to 30 carbon atoms such as 2-aziridinylethanol, 2-azetidinylethanol, 2'-piperidinoethanol, N-methyl-4:azacyclohexanol, and the like; polyaminoalcohols having from 3 to 30 carbon atomssuch as N-methylpiperazinoethanol, N—buty1piperazinoethanol, N-methylpiperazinobutanol, and the like. (Hydroxyalkyl)alkylarylamines and(hydroxyalkyl)diarylamines may also be used in the invention, although their use isnot preferred due to the tendency of compositions comprising aromatic amines todiscolor upon curing. Tertiary amine alcohols including the foregoing examplesthereof‘, may be synthesized according to known methods, or they may becommercially obtained from any of a variety of commercial sources such as Texaco111015202530W0 98/1 1 168CA 02265756 l999-03- 12PCT/US96ll4666Corp. of Houston, Texas; Ashland Chemical Co. of Columbus, Ohio and AldrichChemical Co. of Milwaukee, Wisconsin.In addition to the foregoing tertiary amine alcohols, about two moles of thehydroxyalkyl acrylate is reacted with about one mole of polyfunctional isocyanurate.The hydroxyl group of the hydroxyalkyl acrylate reacts with isocyanate so that themain reaction product comprises acrylate groups pendant to the isocyanurate The double bonds of these acrylate groups provide reactive sites capable of formingadditional bonds with other monomers during polymerization. Suitablehydroxyalkyl acrylate compounds comprise any of a variety of acrylic compoundsincluding hydroxyalkyl acrylates, N-hydroxyalkyl acrylarnides, and the like.Preferredare the hydroxyalkyl acrylates, especially hydroxyalkyl acrylatescomprising a C, to C4 hydroxyalkyl moiety. A particularly preferred hydroxyalkylacrylate is 2-hydroxyethyl acrylate, available from Dow Chemical Co. of Midland,Michigan. 'SECOND MON MERThe foregoing first monomer may be polymerized in a reaction with at leastone additional radiation curable monomer (“second monomer”). In the presence ofa suitable amount of photoinitiator and upon exposure to ultraviolet radiation, thefirst monomer and the second monomers react to form a highly crosslinkedpolymeric coating suitable for use as a floor finish or the like.The second monomer can be selected from any of a variety of radiationsensitive polymerizable monomers including mono-, di- and tri-fiinctional acrylates,as well as acrylates of higher functionality and combinations of the foregoing.Preferably, the second monomer is selected from di- or tri-functional acrylates andcombinations thereof. Suitable di- or tn’-functional acrylates are commerciallyavailable fi'om Sartomer Company, Inc. of West Chester, Pennsylvania. The secondmonomer(s) is chosen to achieve a preferred balance of properties in both theuncured composition as well as in the cured coating. Suitable acrylates for use inthe invention include, without limitation, monoacrylates such as tetrahydrofiirfurylacrylate, cyclohexyl acrylate, n-hexyl acrylate, 2-ethoxyethyl acrylate, isodecylacrylate, 2-methoxyethyl acrylate, 2-(2-ethoxyethoxy)ethyl acrylate, stearyl acrylate,121015202530W0 98ll1168CA 02265756 l999-03- l2PCT/US96/ 14666lauryl acrylate, octyl acrylate, 2-phenoxyethyl acrylate, glycidyl acrylate, isobomylacrylate, benzyl acrylate, tridecyl acrylate, caprolactone acrylate, ethoxylatednonylphenol acrylate, polypropylene glycol acrylate, and the like; diacrylates suchas triethylene glycol diacrylate, ethylene glycol diacrylate, tetraethylene glycoldiacrylate, polyethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate, diethylene glycol diacrylate, hexanediol diacrylate, neopentylglycol diacrylate, tripropylene glycol diacrylate, ethoxylated bisphenol A diacrylate,propoxylated neopentyl glycol diacrylate, and the like; triacrylates such astrimethylolpropane triacrylate, tn's(2-hydroxyethyl)isocyanurate triacrylate,ethoxylated trimethylolpropane triacrylate, pentaerythritol triacrylate, propoxylatedtrimethylolpropane triacrylate, propoxylated glyceryl triacrylate, and the like; higherfunctionality acrylates such as pentaerythritol tetraacrylate, ditrimethylolpropanetetraacrylate, ethoxylated pentaerythritol tetraacrylate, and the like; metallicacrylates such as zinc diacrylate, calcium diacrylate and the like; acrylated oligomersand polymers such as polyurethane mono- and poly- acrylates, polyester mono- andpoly- acrylates, polyamide mono- and poly- acrylates, polybutadiene mono- andpoly- acrylates, and the like; and, acrylated silicones such as those available underthe trade designations “EBECRYL 350” or “EBECRYL 1360” fi'om UCB Radcureof Smyrna, Georgia.The second monomer may comprise substances other than acrylatedmonomers, preferably substances that readily copolymerize with acrylate monomerssuch as the foregoing acrylated first monomer used in the present invention.Suitable materials include N-vinyl monomers such as N’-vinylfonnamide, N-vinylpyrrolidone, N-vinylcarbazole, and the like; acrylamide and derivatives thereofsuch as methylolacrylamide; styrenic monomers such as styrene, a-methylstyrene,vinylpyridine, and the like; and other monomers such as vinyl ethers, allyl etherssuch as triallyl isocyanurate, allyl acrylate and ether maleate esters, for example.Acrylated substances are preferred for use as the second monomer herein.Most preferred are ethoxylated trimethylolpropane triacrylates such as thosecommercially available from Sartomer Company under the trade designations “SR131015202530W0 98/11 168CA 02265756 l999-03- l2PCT/US96/14666454”, “SR 499”, “SR 502” and “SR 903 5” and propoxylated diacrylates such astripropylene glycol diacrylate.As mentioned, the second monomer(s) is added to a reaction mixture withthe first monomer and polymerized to form the hard, durable, clear coatings of theinvention, as is fiirther described below. In the reaction mixture, the weightpercentage of the second monomer is typically within the range from about 5 toabout 90%, preferably from about 35 to about 70 wt% and more preferably fromabout 45 to about 65 wt%. The first monomer is present within the mixture at aconcentration within the range from about 10 to about 90 wt%, preferably fromabout 25 to about 60 wt%, and more preferably from about 30 to about 50 wt%.PHOTOINITIATQRAs mentioned, photoinitiator is added to the compositions of the inventionto initiate the polymerization reaction. Preferred photoinitiators are free radicalinitiators for ultraviolet curing. In the selection of a suitable photoinitiator for usein the present invention, special attention is given to the properties of high molarabsorptivity (e.g., extinction coefficient) at the power maxima for the light source,low color and low tendency to color after UV exposure, shelf life stability, low orpleasant odor and high efficiency for photoinitiation of polymerization. In order toachieve a rapid and satisfactory cure of the compositions of the invention, thephotoinitiator will preferably have a high molar absorptivity (e.g., greater than10,000 liter/mole-cm) at one wavelength of the light source, while having a lessermolar absorptivity at another or second wavelength of the light source (e.g., lessthan 10,000 liter/mole-cm). Preferably, the compositions of the invention willcontain photoinitiators in concentrations such that the absorbance for a 25 micronfilm will be greater than or equal to about 2.5 at one wavelength (typically 254 nm)to assure a rapid surface cure, while the absorbance at the longer wavelength(typically 350-3 70 nm) will be from about 0.05 to about 0.8, and more preferablyfrom about 0.4 to about 0.6 to ensure a rapid and effective through cure.The photoinitiators useful in the invention include those known as usefiil inthe UV cure of acrylate polymers. Such initiators include benzophenone and itsderivatives; benzoin, at-methylbenzoin, a-phenylbenzoin, a-allylbenzoin, a-141015202530W0 98/11168CA 02265756 l999-03- l2PCT/US96/ 14666benzylbenzoin; benzoin ethers such as benzil dimethyl ketal ((commercially availableunder the trade designation “IRGACURE 651" from Ciba-Geigy of Ardsley, NewYork), benzoin methyl ether, benzoin ethyl ether, benzoin n-butyl ether;acetophenone and its derivatives such as 2-hydroxy-2-methyl-1-phenyl-1-propanone(commercially available under the trade designation “DAROCUR l173” from Ciba-Geigy of Ardsley, New York) and 1-hydroxycyclohexyl phenyl ketone (HCPK)(commercially available under the trade designation “IRGACURE l84”, also fromCiba-Geigy Corporation); 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone commercially available under the trade designation “IRGACURE 907”,also from Ciba-Geigy Corporation); 2-benzyl-2-(dimethlamino)-1-[4-(4-morpholinyl)phenyl]-1-butanone commercially available under the trade designation“IRGACURE 369”, also from Ciba-Geigy Corporation). Other usefulphotoinitiators include pivaloin ethyl ether, anisoin ethyl ether; anthraquinones suchas anthraquinone, 2—methylanthraquinone, 2-ethyl anthraquinone, 2-t-butylanthraquinone, 1-chloroanthraquinone, 2-bromoanthraquinone, 2-nitroanthraquinone, anthraquinone-1-carboxaldehyde, anthraquinone-2-thiol, 4-cyclohexylanthraquinone, 1,4-dimethylanthraquinone, 1-methoxyanthraquinone,benzathraquinonehalomethyl triazines; ‘onium salts, for example, diazonium saltssuch as phenyldiazoniumhexafluorophosphate and the like; diaryliodonium saltssuch as ditolyliodonium hexafluoroantimonate and the like, sulfonium salts such astriphenylsulfonium tetrafluoroborate and the like; titanium complexes such asbis(n5-2,4-cyclopentadien-1-yI)bis[2,6—difluoro-3 -(1H-pyrrol-1-yl)phenyl]titaniumcommercially available under the trade designation “CGI 784 DC”, also from Ciba—Geigy Corporation); uranyl salts such as uranyl nitrate, uranyl propionate;halomethylnitrobenzenes such as 4-bromomethylnitrobenzene and the like; mono-and bis-acylphosphines such as those available from Ciba-Geigy under the tradedesignations “IRGACURE 1700”, “IRGACURE 1800”, “IRGACURE 1850” and“DAROCUR 4265”. It is contemplated that other photoinitiators not listed hereinmay also be suitable for use in the present invention. The selection of a suitablephotoinitiator is well within the skill of those practicing in the field.151015202530WO 98111168CA 02265756 l999-03- l2PCT/US96/14666A preferred photoinitiator used in this composition is a combination ofabout 4 parts by weight benzophenone (based on the total weight of thecomposition) and 1 part by weight N-ethylcarbazole or N-vinylcarbazole. Anotherpreferred photoinitiator is a combination of about 4 parts by weight benzophenone(based on the total weight of the composition) and 1 part by weight benzoindimethyl ketal. Preferably, the photoinitiator is present in the compositions of theinvention at a concentration between about 2 and about 10 wt% and morepreferably between about 4 and about 7 wt%.OTHER INGREDIENTSAdditional optional components can be included within the coatablecompositions of the invention. For example a wetting agent may be added in minoramounts to the coatable compositions to facilitate uniform coating over a suitablesubstrate. Suitable wetting agents include, for example, fluofinated agents such asthose commercially available under the trade designations “FLUORAD FC-431”and “FLUORAD FC-171", both available from the Minnesota Mining andManufacturing Company of St. Paul, Minnesota.Fillers may be added to the coatable compositions of the invention to modifywear properties. Fillers known to be usefiil in acrylate clear coat applications maybe used in the invention. A preferred filler is one in which silica particles aremodified with 3-mercaptopropyltrimethoxysilane.Other possible ingredients include defoamers, leveling aids, mar and slipadditives, air release additives, antioxidants, light stabilizers such as benzotriazolelight stabilizers, hydroxybenzophenone light stabilizers and the like; opticalbrighteners and other known formulation additives.PREPARATI N AND U E OF COATABLE COMPOSITI NSIn the preparation of the coatable compositions of the present invention, thefirst monomer is preferably prepared first and then blended with the secondmonomer(s), photoinitiator and other ingredients.In the preparation of the first monomer, the polyfunctional isocyanurate isfirst added to a reaction vessel along with a suitable catalyst such as dibutyltindilaurate. A mixture is prepared by the addition of the tertiary amine alcohol and161015202530W0 98/11168CA 02265756 l999-03- 12PCTIUS96/ 14666the hydroxyalkyl acrylate. A suitable preservative that will not be consumed duringthe reaction such as, for example, butylated hydroxytoluene (BHT) may also beadded to the reaction mixture. The mixture of tertiary amine alcohol, hydroxyalkylacrylate and preservative are added to the reaction vessel (containing the firstmonomer). The reaction is allowed to proceed to completion under ambientconditions in air while controlling the temperature of the reaction mixture,preferably at a temperature below about 40°C to prevent the prematureconsumption of the preservative. The reaction mixture is then allowed to cool toroom temperature. Completion of the reaction may be monitored by appropriatemeans, such as by infrared spectrophotometry.The thus prepared first monomer may then be combined in an appropriatereaction vessel with a second monomer, photoinitiator and other optionalingredients to provide the coatable compositions of the invention. A particularlypreferred coatable composition according to the invention is one comprising about42 parts by weight first monomer (preferably DESMODUR XP 7100 isocyanuratecommercially available from Bayer Corporation), about 48 parts by weight ofethoxylated trimethylolpropane triacrylate (commercially available under the tradedesignation “SR-499” from Sartomer Company, Inc.), about 5 parts by weight oftripropylene diacrylate, about 5 parts by weight photoinitiator and about 0.3 partsby weight of a suitable wetting agent (e.g., FLUORAD F C-171 from MinnesotaMining and Manufacturing Company), and about 0.5 parts of the acrylated siliconeEBECRYL 350 commercially available from UCB Radcure of Smyrna, Georgia.In order to prolong storage of the compositions of the invention inhibitorsmay be added. Suitable inhibitor may be any material known to inhibit free-radicallyinduced polymerization including, but not limited to hindered phenols such asbutylated hydroxytoluene (BHT) and its derivatives, hydroquinone and itsderivatives such as methylhydroquinone, and N-nitrosophenylhydroxylaminealuminum salt commercially available under the designation “Q-1301” from WakoChemicals USA, Inc. (Richmond, VA). Of these N-nitrosophenylhydroxylaminealuminum salt is preferred.171015202530W0 98/11 168CA 02265756 l999-03- l2PCT/US96/ 14666The composition may then be coated onto a suitable substrate such as aconventional polyvinyl chloride floor tile, for example. Once coated over thesubstrate, the coatable composition is exposed to UV light to cure the compositionto a hardened protective coating. Suitable light sources may be selected by thoseskilled in the art. In general, high intensity light sources are preferred to achieve afast cure of the coatable composition. However, in the application of the coatablecompositions to installed flooring, low intensity UV light may be more practical,and the coatable compositions of the invention are readily curable by brief exposureto low intensity UV light. In general, a suitable low intensity UV light source is onethat emits at least one band of wavelengths less than about 300 nm. To achieve afaster cure of the applied coating, the light source will preferably also emit a secondband of wavelengths between about 300 and 400 nm. It has been found that forcoating thicknesses of about 0.03 mm, a UV light source that emits a narrow band 'of wavelengths centered around 254 nm at an intensity (at the surface of thecoating) of approximately 5-15 mW per square centimeter is adequate. Preferably,such a low intensity light source also emits a second narrow band of wavelengthscentered in the range 360-3 70 nm and typically around 365 nm at the sameapproximate intensity as mentioned. At the foregoing low level UV intensity, thecompositions of the present invention will normally cure in less than 30 seconds,preferably in less than 20 seconds. One such light source is that described below inthe Examples.It will be appreciated that the overall configuration of the light source isoutside the scope of the invention. Different light sources may be used to effectcuring of the compositions of the invention such as a pulsed xenon flash source, amedium pressure mercury source, a low pressure mercury fluorescent source and a300 nm fluorescent source. It is also contemplated that longer wavelength lampscould be used to initiate the polymerization reaction if a suitable photoinitiator isused.In applying the coatable compositions of the invention to a suitablesubstrate, it is preferred that the composition be applied in manner which creates acoating no greater than about 1.3 millimeters in thickness in order to facilitate181015202530W0 98/1 1 168CA 02265756 l999-03- l2PCT/US96/14666curing of the composition within the aforementioned time limits. Coatings of thisthickness can be achieved by any of a number of known application techniques suchas roll coating, squeegeeing, knife coating, curtain coating, spray coating, and thelike. In applying the forgoing compositions to a substrate, suitable substratesinclude conventional floor tiles which may or may not be previously coated orsealed. When the substrate to be coated is vinyl tile or the like, it is preferred thatthe substrate is first treated with a primer or sealer prior to the application of theUV curable inventive compositions to that substrate. A primer treatment of thesubstrate facilitates the case at which the UV cured coating may subsequently beremoved fi'om the tile or other substrate by a chemical stripping formulation, forexample. In order to promote adhesion of the coatable composition to thesubstrate, an acrylated latex primer is most preferred. The acrylated latexcompositions useful herein must have at least one free—radically polymerizablegroup pendant from each latex particle, and preferably more than one. The latex ishydrophobic in nature, but may contain some hydrophilic groups.When applying the primer to the substrate, it is desirable to provide acontinuous film over the surface of the substrate, adjusting the solids content of theprimer as needed to achieve such a film while using the least amount of primerrequired to achieve a barrier layer with the desired adhesion properties. Typically,the solids content of the primer required for a wipe on coating (e.g., by hand) willbe between about 2 and about 40% by weight, preferably between about 2 andabout 20%, and more preferably between about 4 and about 15%. A wetting agentor defoamer may be added to the latex emulsion to improve coating properties.The level of such additives will depend on the nature of the substrate and theconcentration of the latex emulsion.One preferred latex emulsion for use as a primer herein is the acrylatedemulsion commercially available under the trade designation “ROSI-HELD 3120"from Rohm and Haas Company, Philadelphia, PA. This emulsion is available at asolids content of about 40.5% by weight, and a suitable primer can be prepared bydilution of the concentrated emulsion at a dilution weight ratio of up to about 9:1(water: emulsion). More preferred is an aqueous primer formulation comprising a191015202530W0 98/ l 1 168CA 02265756 l999-03- l2PCTlUS96/ 14666blend or the foregoing ROSHIELD 3120 acrylated latex with a second primerpolymer, preferably the ammonium salt of a styrene maleic anhydride (SMA)copolymer (commercially available at a solids content of 38.5% under the tradedesignation “SMA lO00A” from Atochern, Inc. of Malvem, Pennsylvania). TheSMA is added to the primer to act as a leveling aid. The weight ratio of the acrylateto the SMA copolymer in the primer is preferably between about 7:1 and about 12:1and more preferably is about 10:1. A small amount of surfactant may also beincluded in the primer. A particularly preferred primer, having a solids content ofabout 10 % by weight, comprises about 24.4 wt% of the ROSHIELD 3120acrylated latex, about 73.2 wt% water, about 2.4 wt % SMA 1000A copolymer andabout 0.02 wt% surfactant or wetting agent such as that commercially availableunder the trade designation “FLUORAD FC-l29” from Minnesota Mining andManufacturing Company, St. Paul, Minnesota. 'The primer may be applied to the substrate by any suitable method such aswiping, brushing, spraying and the like. The latex is allowed to dry, typically underambient conditions, and the UV curable compositions of the invention may then beapplied thereover and cured, as described herein. Substrates such as PVC tiles, forexample, coated with the above acrylated latex primer and then coated with a UVcurable acrylate (e.g., a coatable composition) may be readily stripped using abenzyl alcohol stripper such as that described below in the Examples. The thusstripped tiles present a very good appearance with stripping appearing to occur atthe surface of the tile. Corresponding unprimed tiles coated with the same UVcurable acrylate are slower to strip and generally do not strip cleanly (e.g., at thesubstrate surface).In the above described aspect of the invention, the primer can comprise acomponent of a floor finishing system that includes both the primer as well as thecoatable composition described herein. Although primers comprising the foregoingROSHIELD 3120 acrylated latex (with or without added SMA copolymer) arepreferred, other commercially available materials may also be used as primers oncertain substrates such as on PVC composition floor tile. Some suitable primersinclude various commercial floor sealers such as those available under the trade201015202530W0 98/1 1168CA 02265756 l999-03- l2PCT/U S96/ 14666designations “CORNERSTONE” (Minnesota Mining and Manufacturing Company,St. Paul, Minnesota), “TOPLINE” (also from Minnesota Mining and ManufacturingCompany) and “TECHNIQUE” (S.C. Johnson of Milwaukee, Wisconsin). It is alsocontemplated that the foregoing primer, especially primers comprising ROSI-HELD3120 acrylated latex, may be used in other applications outside the floor finishingart to apply any of a variety of UV polymerizable polymers (e.g., other than theforegoing coatable compositions) to a substrate. Accordingly, the use of the primerprovides a system and a method for coating a variety of substrates with a UVcurable polymer. In such a system and method, the resulting coatings adhere wellto the substrate and may also be more easily removed from the substrate by suitablestripper compositions. When using a non-acrylated latex primer it is preferable touse a primer which has a surface tension of at least 40 dynes/cm.The cured coatings of the invention may be stripped from the substrates towhich they are applied by the application of a suitable stripper. Preferably, thestripper is a pH neutral formulation comprising a solvent, coupling agent (e.g.,hydrotrope) and water. Dye, fragrance and thickening agent may be added to thestripper composition if desired. An effective stripper formulation for the floor finishcompositions of the invention includes those set forth below in the Test Methods.EXAMPLESMATERIAL AIngredients used in the Examples below are identified as follows:DESMODUR N3300 is the trade designation for a hexane diisocyanate trimeravailable from Bayer Corp., Industrial ChemicalsDivision.DESMODUR XP 7100 is the trade designation for an allophanated hexanediisocyanate trimer mixture available from Bayer Corp.,Industrial Chemicals Division.DESMODUR XP 7040 is the trade designation for an allophanated hexanediisocyanate trimer mixture available from Bayer Corp.,Industrial Chemicals Division.211015202530W0 98/ 11 168SR 306SR 335 2SR 454SR 499DAROCUR 1 173DAROCUR 4265IRGACURE 184FLUORAD FC-431FLUORAD FC-17102265756 l999-03- 12PCTIUS96/14.666is the trade designation for tripropylene glycoldiacrylate, a difunctional acrylate monomercommercially available from Sartomer Co., Inc. of WestChester, PA.is the trade designation for lauryl acrylate, amonofunctional acrylate monomer commerciallyavailable from Sartomer Co., Inc. of West Chester, PA.is the trade designation for ethoxylatedtrimethylolpropane triacrylate a trifimctional acrylatemonomer commercially available from Sartomer Co.,Inc. of West Chester, PA.is the trade designation for ethoxylatedtrimethylolpropane triacrylate a trifimctional acrylatemonomer commercially available from Sartomer Co.,Inc. of West Chester, PA.is the trade designation for 2-hydroxy2-methyl-l-phenylpropan-1-one, a photoinitiator commerciallyavailable from Ciba-Geigy, Ardsley, New York.is the trade designation for an acylphosphinephotoinitiator commercially available from Ciba-Geigy,Ardsley, New York. 4is the trade designation for 1-hydroxycyclohexyl phenylketone, at photoinitiator commercially available fromCiba-Geigy Corporation, Ardsley, New York.is the trade designation for a wetting agent availablefrom Minnesota Mining and Manufacturing Company,St. Paul, Minnesota.is the trade designation for a wetting agent availablefrom Minnesota Mining and Manufacturing Company,St. Paul, Minnesota.221015202530W0 98/11168PVC TileSealed PVC TileROSHIELD 3120EBECRYL 350TECHNIQUETOPLINECORNERSTONEPREPARATIVE PR02265756 l999-03- 12PCT/US96/ 14666refers to standard floor tile comprising polyvinylchloride that has been stripped and cleaned to removethe factory finish.refers to standard floor tile comprising polyvinylchloride that has been stripped and cleaned to removethe factory finish and then coated with a floor finish orsealer.is the trade designation for an acrylated emulsioncommercially available from Rohm and Haas Company,Philadelphia, PA at a solids content of 40.5% byweight, and used herein as a primer by dilution of theconcentrate with water at a dilution ratio of 9:1(water:emulsion).is the trade designation for acrylated siliconescommercially available fi'om UCB Radcure of Smyrna,Georgia.is the trade designation for an acrylic floor sealercommercially available from S.C. Johnson, Milwaukee,Wisconsin.is the trade designation for an acrylic floor finishcommercially available from Minnesota Mining andManufacturing Company, St. Paul, Minnesota.is the trade designation for an acrylic floor -finishcommercially available from Minnesota Mining andManufacturing Company, St. Paul, Minnesota.DUREThe following procedures were used in the preparation of materials used anddescribed in the Examples.Preparation of Oliggmer AA dry five-liter reaction vessel was fitted with a drying tube, addition funnel,thermometer and mechanical stir and charged with 450.0 g (2.30 eq) of hexane231015202530W0 98/11168CA 02265756 l999-03- 12PCT/U S96! 14666diisocyanate trimer (DESMODUR N 3300). Four drops of dibutyltin dilauratewere added to the reaction vessel. A mixture was prepared by mixing 68.43 g 2-(N,N-dimethylamino)ethanol (0.77 eq.), 178.3 g 2-hydroxyethyl acrylate (1.54 eq.)and 0.35 g methylhydroquinone as a preservative. This mixture was added to thereaction vessel while maintaining the temperature of the contents below 35° C.When the mixture had cooled to room temperature it was isolated by pouring it intoa container. Infrared analysis indicated only trace amounts of isocyanate or freealcohol present. This material was very viscous, requiring a spatula to dispense.Preparation of Oligomer BA dry five-liter reaction vessel was fitted with a drying tube, addition funnel,thermometer and mechanical stir and charged with 600.0 g (2.93 eq.) ofallophanated hexane diisocyanate trimer (DESMODUR XP 7100). A mixture wasprepared by mixing 87 g 2-(N,N-dimethylarnino)ethanol (0.975 eq.), 226.7 g 2-hydroxyethyl acrylate) (1.95 eq.) and 0.45 g BHT as a preservative. 9 dropsdibutyltin dilaurate were added to the reaction vessel. The mixture was added tothe reaction vessel while maintaining the temperature of the mixture below 30° C.When the mixture had cooled to room temperature it was isolated by pouring it intoa container. Infrared analysis indicated only trace amounts of isocyanate or freealcohol present. This material was moderately viscous and difficult to pour.Preparation of Oligomer CA dry one-liter reaction vessel was fitted with a drying tube, addition funnel,thermometer and mechanical stir and charged with 642 g (3.018 eq.) allophanatedhexane diisocyanate trimer (DESMODUR XP 7040). 6 drops dibutyltin dilauratewere added to the reaction vessel. A mixture was prepared by mixing 89.7 g 2-(N,N-dimethylamino)ethanol (1.01 eq.), 233.7 g 2-hydroxyethyl acrylate (2.012eq.) and 0.48 g BHT as a preservative. This mixture was added to the reactionvessel while maintaining the temperature of the contents below 40°C. When themixture had cooled to room temperature it was isolated by pouring it into acontainer. Infrared analysis indicated only trace amounts of isocyanate or freealcohol present. This material had low viscosity and was easily pourable.241015202530W0 98/11168CA 02265756 l999-03- l2PCT/US96/14666Prgpargion QfMgdified Silicg PagtigleszMercapto-functionalized silica was prepared. 1176 grams of an aqueousdispersion of colloidal silica having a solids content of 34 wt% at a pH of 3.2(commercially available from Nalco Chemical Company of Naperville, Illinois underthe trade designation NALCO 1042) was diluted to 10% total solids with distilledwater to give 4000 g total. To this was added 19.6 g of (3-mercaptopropyl)trimethoxysilane (available from Aldrich Chemical Company,Milwaukee, Wisconsin). The resulting suspension was heated for 18 hours at 80°Cwith stirring to give a translucent, colorless suspension which was used withoutpurification. A portion of the above suspension (50 g) was mixed with 45 g SR 499to give a slurry. The water was removed under vacuum (aspirator/rotovap) at roomtemperature to give 50 g of a clear liquid.GENERAL PROCEDLJLESCuring Procedure AUV exposures were made using a wheeled cart capable of running ofi‘ 11.0 Vpower having a front mounted downward facing bank of 18 inch (45.7cm)fluorescent lights on 1.5 inch (3.81 cm) centers at a distance of approximately 1inch (2.54 cm) from the floor. The lights were cantilevered in front of the cartwheels to allow for forward motion over uncured floor coating without marring thefinish. A reflective aluminum sheet was mounted behind the lights to boost theradiant energy directed toward the coating. The lamps were in two sets within thebank. The first set consisted of two 15 watt lights on a 25 watt ballast in the frontof the bank. These two lights consisted of one (1) 15 watt germicidal light (a lowpressure mercury light emitting at about 254 nm) and one (1) 15 watt blacklight(365 nm). The second set consisted of six (6) 15 watt lights on a 15 watt ballast.The second set was positioned in the bank with a two inch gap between the twolight sets. The second light set consisted of alternating germicidal and blacldightsfor a total of six (6) lights in the second set.All of the germicidal bulbs were commercially available from GeneralElectric under the designation “F15T8”. The blacklight bulbs were also available2510152025W0 98/11168CA 02265756 l999-03- 12PCT/US96/14666from General Electric under the designation “F15T8/BL”. Power measured at thegermicidal bulb surface in the bulb center was about 11 mW/cmz for the 25 wattballast and about 7 mW/cm’ for the 15 watt ballast. Power measured at theblacklight bulb surface in the bulb center was about 7 mW/cm’ for the 25 wattballast and about 4.5 mW/cm’ for the 15 watt ballast.Unless otherwise indicated, all samples were cured in a 30 second exposureto the above light source.Curing Procedure BExposures were made using a downward facing bank of 18” fluorescentlights on 1.5 inch centers at a distance of approximately 1 inch from the floor. Areflective aluminum sheet was mounted behind the lights to boost the radiant energydirector toward the coating. The light set consisted of six gennicidal bulbs.All of the bulbs were commercially available from General Electric under thedesignation “F15T8”. Power measured at the bulb surface in the bulb center wasabout 7 mW/cmz.Unless otherwise indicated, all samples were cured in a 30 second exposureto the above light source.Coating Procedure AIn applying the coatable compositions to a substrate such as PVC Tile orSealed PVC Tile, a small volume of the composition, typically about 2-3 grams, wasapplied to the substrate using a syringe. The thus applied composition was thencoated over the substrate by using a hand held rubber roller to roll the compositionover the desired area of the substrate until a fairly uniform coating was _obtainedover the desired area of the substrate. The composition was then cured. Todetermine the coating weight, the weight of the coated tile was compared to theinitial tile weight (e.g., before applying the coatable composition).TE§T METHODSIn the Examples which follow, the following test methods were employed.261015202530W0 98/1 1 168CA 02265756 l999-03- 12PCT/US96/ 14666Test M d A T b Abrasion Re is an e :A 4" x 4" square sample of coated material to be tested was prepared. Usinga template to precisely locate a spot on the coating where the abrasion wasexpected to occur, an initial 20° or 60° gloss reading was obtained for each side(four readings total) using a Byk-Gardner Micro-Tri-Gloss meter (Byk-Gardner,Silver Spring, MD). The sample was then mounted on a Taber Standard AbrasionTester (model no. 503, Teledyne Taber, North Tonawanda, NY) fitted with avacuum attachment, 500 g wheel weights and CS-10f wheels. The sample wassubjected to 100 revolutions and the gloss afier abrasion was measured as before.The percent gloss retention for each side was calculated, and the results wereaveraged.Test Method B (Scratch Hardness)Scratch hardness was determined using a Byk-Gardner pencil-type scratch tester(Byk-Gardner, Silver Spring, MD). Measurements were reproducible to about _-t100 g. The results were generally substrate and film thickness dependent.Tes_t Methgd Q (Strip Time)In testing the coatings of the invention to determine the amount of timerequired to strip a radiation-cured coating from a substrate, the followingformulation was used to strip coatings fi'om tile substrates: 68.75 parts deionizedwater, 22.50 parts benzyl alcohol, 5.52 parts n-octylamine, 3.24 parts glycolic acid,0.02 parts surfactant (“FLUORAD FC-129” from Minnesota Mining andManufacturing Company).The stripper was applied by a dropper onto a cured coating at numerouslocations on the coating. The strip time recorded was the time at which either 1)the film bubbled up over the entire area covered with stripper; or 2) the timerequired for the stripper to sufficiently loosen the coating so that hand wiping of theapplied stripper with a paper towel resulted in a clean stripped substrate surface.Condition 1 was generally observed for coatings applied over Sealed PVC Tilewhile condition 2 was generally observed for PVC Tile. The strip time is highlysensitive and will depend on coating thickness as well as the degree of cure for aparticular coating. Consequently, care must be taken in comparing strip time results2710152025WO 98111168CA 02265756 l999-03- l2PCT/U S96! 14666of coatings having difierent thicknesses or those that have experienced differentdegrees of cure.Test M h D loss MeasuremenGloss measurements were made using a calibrated Byk-Gardner Micro-Tri-Gloss meter (Byk-Gardner, Silver Spring, MD). Readings were taken following acleaning of the surface.Test Method E (Color Measurement)Color measurements were made using a calibrated Datacolor InternationalMicroflash 200d spectrophotometer (Datacolor International, Charlotte, NC) inspecular mode using a 1.5 cm aperture. All readings were an average of 3measurements. CIELAB color coordinates L‘, a*, b* and the color shift DE usedherein are well known terms in color measurement.EXAMPLESThe following non-limiting Examples illustrate the preparation, utility andthe comparative advantages of the present invention. Unless otherwise indicated,all parts and percentages are by weight.EXAMPLES 1 - 15Examples 1-15 were prepared and evaluated for durability according to TestMethod A. Analysis of the results indicates that formulations with reduced amountsof the SR-306 difunctional acrylate have the best durability. All samples contained0.3 parts FC-431 FLUORAD wetting agent, and were coated onto PVC Tile. Theywere coated at 2.5 g / ft2 (26.9 g/m2) using Coating Procedure A and cured usingCuring Procedure A. The formulations for these Examples and the abrasionresistance data are set forth in Table 1.28CA 02265756 l999-03- 12W0 98/11168 PCT/US96/14666Table 1Examples 1-15Formulation Parts Parts Parts Parts % 20° Gloss StandardExample Oligomer SR—499 SR-306 DAROCUR Retention DeviationA 11731 50.00 35.00 15.00 5 74.0 4.82 30.00 45.00 25.00 5 43.1 8.13 40.00 42.50 17.50 5 67.0 2.64 40.00 35.00 25.00 5 63.5 3.05 35.00 50.00 15.00 5 70.9 3.46 40.00 35.00 25.00 5 66.3 3.27 40.00 42.50 17.50 5 74.2 1.98 50.00 40.00 10.00 5 78.2 1.79 45.00 45.00 ' 10.00 5 77.8 1.511 40.00 50.00 10.00 5 77.2 1.412 50.00 40.00 10.00 5 76.4 3.513 30.00 45.00 25.00 5 64.1 3.014 30.00 50.00 20.00 5 56.1 3.415 45.00 35.00 20.00 5 64.2 2.1EXAMPLE 16A series of samples were prepared based in part on the above data forExamples 1 - 15. The Example 16 samples were made with 40 parts Oligomer A,45 parts trifimctional acrylate (SR-499), 10 parts difimctional acrylate (SR-306),0.3 parts wetting agent (FLUORAD FC-431) and photoinitiator. 5 parts of aphotoinitiator such as the DAROCUR 1173 material or other photoinitators wereall used successfiilly including 3 parts benzophenone combined with 2 parts ofeither DAROCUR 1173 photoinitiator or IRGACURE 184 photoinitiator. Thesecompositions were coated over Sealed PVC Tile that had an applied primer coat ofCORNERSTONE floor sealer according to Coating Procedure A and curedaccording to Curing Procedure A. Abrasion resistance, scratch hardness, and striptimes were determined according to the above Test Methods A, B and C. The %20° gloss retention for these samples was consistently about 83%. Scratch hardnesswas about 1200 g. Strip time was less than 5 minutes.291015W0 98llll68CA 02265756 1999-03- 12PCT/US96/ 14666EXAMPLE 17 - 30Examples 17-30 were prepared and evaluated for abrasion resistanceaccording to Test Method A. Analysis of the results ‘indicates that formulationswith reduced amounts of the SR-306 difunctional acrylate have the best durability.All samples contained 0.3 parts wetting agent (FLUORAD FC-431), and werecoated onto PVC Tile. They were coated at 2.5 g / ft2 (26.9 g/m2) using a CoatingProcedure A and cured using Curing Procedure A. The compositions of theExamples and the abrasion resistance data are set forth in Table 2.Table 2Examples 17-30Formulation Parts Parts Parts Parts % 20° Gloss StandardExample Oligomer SR-499 SR-306 DAROCUR Retention DeviationB 117317 60 30 5 5 66.7 0.418 60 30 5 5 68.1 1.019 45 45 5 5 75.1 8.320 45 35 15 5 48.8 6.421 45 30 20 5 51.2 4.322 41.25 41.25 12.5 5 62.3 1.123 45 45 5 5 73.4 2.224 45 30 20 5 60.7 1.925 30 45 20 5 7.6 5.226 30 60 5 5 72.9 2.327 37.5 37.5 20 5 56.1 4.128 30 52.5 12.5 5 66.2 4.529 30 60 5 5 69.0 8.730 52.5 30 12.5 5 71.0 3.8EXAIVIPLE 31A series of samples were made based in part on the results of Examples 17-30. All of these samples comprised 30 parts Oligomer B, 65 parts trifimctionalacrylate (SR-499), 0.3 parts wetting agent (FLUORAD FC-431) and 5 partsphotoinitiator. As the photoinitiator, the DAROCUR 1173 photoinitiator was usedsuccessfully by itself as well as other photoinitators including combinations of301015202530W0 98/11168CA 02265756 l999-03- 12PCTIUS96/14666benzophenone and DAROCUR 1173 photoinitiator, and benzophenone andIRGACURE 184 photoinitiator. The samples were coated onto a substrateaccording to Coating Procedure A and cured according to Coating Procedure A.Abrasion Resistance, Scratch Hardness and Strip Time were determined for thecured coatings according to the Test Methods A, B, and C.Using an initiator system of 5 parts DAROCUR photoinitiator and oneadditional part of beniophenone the abrasion resistance after a 15 secondsirradiation was up to 82% gloss retention at 20°. The typical scratch hardness ofthese formulations, when cast onto Sealed PVC Tile (sealed with a poly(viny1idenedichloride) primed polyester film floor sealer commercially available under the tradedesignation "TECHNIQUE" from S.C. Johnson, Milwaukee, Wisconsin) was 800 -1000 g. When coated over conventional floor finishes, delamination was commonlyobserved at forces of as little as 200 g. Strip time from Sealed PVC Tile (when .sealed with a floor finish available under the trade designation “CORNERSTONE”commercially available from Minnesota Mining and Manufacturing Company) wasabout 2-3 minutes.EXAMPLE 32A series of samples were developed based in part on the results of Example16. These samples comprised 40 parts Oligomer C, 45 parts trifimctional acrylate(SR—499), 10 parts difimctional acrylate (SR-306), 5 parts photoinitiator and 0.3parts wetting agent (FLUORAD FC-431). The DAROCUR 1173 photoinitator andother photoinitators were all used successfully including combinations ofbenzophenone and DAROCUR 1173 photoinitator, and benzophenone andIRGACURE 184 photoinitator. The samples were coated onto a substrateaccording to Coating Procedure A and cured according to Coating Procedure A.Abrasion Resistance, Scratch Hardness and Strip Time were determined for thecured coatings according to the Test Methods A, B, and C. The abrasion resistance(% 20° Gloss Retention) was consistently 85%, the scratch hardness was 1300 g,and strip time from Sealed PVC Tile (sealed with a floor sealer commerciallyavailable under the trade designation “Comerstone” from Minnesota Mining andManufacturing Company) was less than 5 minutes.31CA 02265756 l999-03- 12W0 98/ 11168 PCT/U S96/ 14666EXAMPLES 33 - 60:Examples 33-60 were prepared and evaluated for abrasion resistanceaccording to Test Method A. All samples contained 0.3 parts wetting agent(FLUORAD FC—43 1). The formulations of the Examples were coated onto PVCTile at a dry coating weight of 2.5 g / R2 (26.9 g/m2) using Coating Method A andcured using Curing Method A. The compositions for Examples 33-60 and theabrasion resistance data is set forth in Table 3. Analysis of the results indicates thatformulations with reduced amounts of the SR-335 monofunctional acrylate have thebest durability.Table 3Examples 33-60Formulation Parts Parts Parts Parts % 20“ Glass % 60° GlossExample Oligomer SR-454 SR-335 DAROCUR Retention RetentionA 1173 '33 45.00 35.00 20.00 5 62.50 67.8834 30.00 20.00 50.00 5 No Cure No Cure35 30.00 50.00 20.00 5 62.80 37.1336 35.00 25.00 40.00 5 No Cure No Cure37 30.00 50.00 20.00 5 29.39 36.4738 30.00 20.00 50.00 5 No Cure No Cure39 45.00 35.00 20.00 5 48.56 56.8140 35.00 40.00 25.00 5 53.81 59.6941 60.00 20.00 20.00 5 57.43 68.2342 60.00 20.00 20.00 5 46.32 57.1543 30.00 35.00 35.00 5 No Cure No Cure44 50.00 25.00 25.00 5 65.36 76.8945 45.00 20.00 35.00 5 No Cure No Cure46 40.00 30.00 30.00 5 No Cure No Cure47 57.50 30.00 12.50 5 52.90 70.6048 50.00 30.00 20.00 5 56.90 64.9049 50.00 50.00 0.00 5 56.80 75.2050 57.50 42.50 0.00 5 51.20 69.2051 60.00 38.33 1.67 5 59.50 77.2052 50.00 30.00 20.00 5 59.60 68.8053 65.00 35.00 0.00 5 68.30 79.0032101520CA 02265756 l999-03- l2PCT/US96/14666W0 98/ 1 1 16854 65.00 30.00 5.00 5 62.70 75.5055 50.00 50.00 0.00 5 53.40 74.4056 57.50 36.25 6.25 5 64.40 74.8057 50.00 40.00 10.00 5 60.80 70.1058 50.00 40.00 10.00 5 66.30 73.5059 60.00 31.67 8.33 5 68.20 80.8060 57.50 36.25 6.25 5 74.20 80.50EXAMPLE 61A series of samples were developed based in part on the results of examples33-60. These samples comprised 177 parts Oligomer A, 102 parts trifunctionalacrylate (SR-454), 21 parts monofunctional acry1ate(SR-335), 15 partsphotoinitiator (DAROCUR 1,173), 0.3 parts wetting agent (FLUORAD FC-431).The formulation were coated over PVC Tile according to Coating Procedure A andcured according to Curing Procedure A. Abrasion resistance, scratch hardness, andstrip time data was collected for these samples according to Test Methods A, B,and C. Abrasion resistance showed about 74% gloss retention at 20°. Scratchhardness was greater than 1700 grams. Strip time was about 3 minutes.EXAMPLE 62A coatable composition was prepared comprising 60 parts Oligomer A, 21parts trifimctional acrylate monomer (SR-454), 12 parts caprolactone acrylate, 2.4parts photoinitiator (DAROCUR 1173). The sample was coated at about 1 milthickness onto PVC Tile using coating procedure A and cured for 20 seconds underCuring Procedure B. The resulting coating was tested for strip time according toTest Method C, providing a strip time of about 8 minutes.EXAMPLE 63A coatable composition was prepared comprising 60 parts Oligomer A, 20parts trifimctional acrylate (SR-454), 20 parts caprolactone acrylate, 5 partsphotoinitiator (DAROCUR 1173). The composition was coated on PVC Tile usingCoating Procedure A and cured using Curing Procedure A. The resulting coatingswere tested according to Test Methods A, B and C. The Abrasion resistance was33101520W0 98/11 168CA 02265756 l999-03- l2PCTlUS96/ 14666about 75% gloss retention at 60°, scratch hardness was about 500g. The strip timefrom PVC Tile was about 3 min.EXAIVIPLES 64 and 65Examples 64 and 65 were prepared as set forth in Table 4. Example 65 wasidentical to Example 64 except that Example 65 was prepared with functionalizedsilica prepared according to the preparative procedure set forth above. Thecompositions were coated onto PVC Tile according to Coating Procedure A andcured according to Curing Procedure A to provide a cured coating about 0.25 mmthick. The coatings were tested for abrasion resistance according to Test MethodA. The 20° gloss retention values indicated slightly better abrasion resistance forthe coating of Example 65 containing the functionalized silica.Table 4Example 64 and 65Example Composition Average % Standard20° Gloss DeviationRetention64 40 parts Oligomer C, 45 parts trifunctional acrylate (SR- 83.9 4.5499), 10 parts difunctional acrylate (SR-306), 3 partsbenzophenone, 2 parts DAROCUR 1173 photoinitiator65 40 parts Oligomer C, 45 trifunctional acrylate (SR-499) 87.9 2.1containing 10 % functionalized silica, 10 partsdifunctional acrylate (SR-306), 3 parts benzophenone, 2parts DAROCUR 1173 photoinitiator 'EXAMPLES 66-71To determine the eifect of visible light on the color of cured coatings madeaccording to the invention, a premix was prepared. The premix comprised 30 partsOligomer C, 65 parts trifunctional acrylate (SR-499), 5 parts photoinitiator asindicated below, 0.3 parts wetting agent (FLUORAD FC-431). The samples werecoated at 2.5 glitz (26.9 g/m2) onto off white PVC Tile and cured using CuringProcedure A except that curing times were 15 seconds. The cured coatings were34101520W0 98/11168exposed to 6 x 15 W Philips Fl5T8BLB bulbs at a distance of approx. 1 inchCA02265756 l999-03- l2PCT/US96/ 14666(approx. 5 mW/cmz, 350-3 70 nm). Subsequently, the samples were exposed to 6 x15 W Philips ISWTLD/O3 bulbs at a distance of approx. 1 inch (wavelength ofapprox. 420 nm). CIELAB coordinates L*, a* and b* are reported.The L* indicates whiteness, positive a* coordinates measure redness,ositive b* coordinates measure ellowness. DE values measure total colorPdeviation, a DB of less than 1-2 is generally imperceptible to the human eye. Basedon the data set forth in Table 5, it is apparent that UV exposure causes yellowingwhich is reversible upon exposure to blue light.Examples 66-71Table 5EXA1\/IPLE 72-80An oligomer was prepared as in the Preparation of Oligomer B bycombining 42 parts allophanated HDI trimer (DESMODUR XP-7100), 2-hydroxyethyl acrylate, and 2-dimethylamino-ethanol (equivalent ratio of 3 :2: 1).The oligomer was combined with 48 parts trifunctional acrylate (SR-499), 5 partsdifimctional acrylate (SR-306), 3 parts benzophenone, 2 parts DAROCUR 4265photoinitiator and 0.3 parts wetting agent (FLUORAD FC-171) to provide a UVcurable coatable composition. For some of the Examples, EBECRYL 350acrylated silicone was added to the coatable composition as a release material.35Ex- Parts Parts Parts Color coordinates Color coordinates after Color coordinates after 40ample Premix Benzo- DARO- after 15 seconds 45 minutes 350-370 nm min. 420 um lightphenone CUR cure light1173L* a* b"‘ L‘ a‘ b“‘ DE L‘ 3* b* DE66 9.5 0.0 0.5 87.82 1.03 4.67 86.84 1.17 8.72 4.17 86.91 1.20 5.91 1.5567 9.5 0.1 0.4 88.25 1.01 4.81 86.92 1.19 8.31 3.75 87.00 1.16 5.61 1.4968 9.5 0.2 0.3 88.31 1.01 4.74 87.06 1.11 7.19 2.75 86.99 1.14 5.56 1.5669 9.5 0.3 0.2 88.25 1.00 4.79 87.00 1.12 7.04 2.58 86.94 1.10 5.55 1.5270 9.5 0.4 0.1 87.61 1.06 5.04 86.98 1.19 7.83 2.86 87.06 1.11 5.66 0.8371 9.5 0.5 0.0 87.60 1.04 4.91 86.93 1.18 7.81 2.98 87.00 1.09 5.67 0.97101520W0 98/1 1 168CA 02265756 l999-03- l2PCT/U S96/ 14666The coatable compositions were tested for adhesion to both PVC Tile andto Sealed PVC Tile. Sealed PVC Tile was prepared by treating with a primer orsealer applied by hand with gauze to provide a smooth even coating. The primerwas then allowed to dry in air at ambient temperature and humidity.Coatable composition was then applied to both Sealed PVC Tile and PVCTile according to Coating Procedure A and then UV cured according to CuringProcedure A using a 10 second exposure time. After the curing step, cuts weremade with a razor blade through the cured coating and the primer (when present)and into the tile substrate to form a grid of 1/8" x 1/8" (0.32 cm x 0.32 cm) squares.Tape (“SCOTCH Rug and Carpet Tape” available from Minnesota Mining andManufacturing Company) was appliedonto the square pattern with a 2.3 kg roller.The tape was then peeled by hand from the tile by grabbing an end thereof andpulling the tape back over itself at about a 180° angle. Adhesion was determined byvisual inspection of both the tile and the removed tape to determine the percentageof the square sections removed from the tile. A value of 0% adhesion means all ofthe coating was removed fi'om the tile while 100% adhesion means none of thecoating was removed. In general, all UV cured coatings adhered well to the tilesubstrate with better adhesion observed on Sealed PVC Tile, especially those sealedwith the ROSHIELD 3120 latex.The composition of the UV curable coatings, the primer layer used and thedata for the adhesion test are all summarized in Table 6. Unless otherwiseindicated, the coatings for these Examples comprised 100 parts of the coatablecomposition without added acrylated silicone.36CA 02265756 l999-03- 12W0 98/11168 PCT/US96/14666Table 6(Examples 72-80)EXAMPLE Primer % Adhesion72 none 073 (100 parts coating + 1 part none 0EBECRYL 350 acrylated silicone)74 TECHNIQUE 1075 TOPLINE 076 ROSHIELD 3120 10077 TOPLINE overcoated with 90ROSHIELD 312078 (100 parts coating + 1 part ROSHIELD 3120 100EBECRYL 350 acxylated silicone)79 (100 parts coating + 2 parts ROSHIELD 3120 100EBECRYL 350 acrylated silicone)80 (100 parts coating + 3 part ROSHIELD 3120 100EBECRYL 350 acrylated silicone)Although preferred embodiments of the invention have been described in5 detail, it will be understood that changes and modifications to the describedembodiments may be made by those skilled in the art without departing from thetrue spirit and the scope of the invention, as set forth in the following claims.37

Claims (45)

CLAIMS:

1. A monomer for the formulation of radiation curable coatable compositions, the monomer comprising (a) polyfunctional isocyanurate having at least three isocyanate groups reacted with (b) hydroxyalkyl acrylate or methacrylate and (c) tertiary amine alcohol in a molar ratio of a:b:c of about 1:1-2.5:0.5-2, wherein b + c is at least 3 and no greater than the total number of isocyanate groups of (a).

2. The monomer as defined in claim 1 comprising a compound having the general formula:

wherein R1 and R2 are H or CH3, R3 and R4 independently are straight, branched or cyclic alkyl groups having from 1 to 12 carbon atoms, or R3 and R4 together form a divalent cycloalkanediyl, oxacycloalkanediyl, or azacycloalkanediyl bridging group having from 2 to 12 carbon atoms, and Z1, Z2, Z3, Z4, Z5, and Z6 independently represent divalent groups having from 1 to 18 carbon atoms.

3. The monomer of claim 2, wherein the divalent groups Z1, Z2, Z3, Z4, Z5, and Z6 independently are straight, branched or cyclic alkanediyl groups having from 1 to 18 carbon atoms.

4. The monomer of claim 3, wherein the alkanediyl groups are straight chain alkanediyl groups having from 1 to 4 carbon atoms.

5. A radiation curable coatable composition, comprising:

(a) the monomer of claim 1 as first monomer;
(b) a second monomer; and (c) photoinitiator.

6. The coatable composition as defined in claim 5, wherein the first monomer is present within the composition in an amount between about 10% and about 90% by weight.

7. The coatable composition as defined in claim 5 or 6, wherein the second monomer further comprises an acrylate.

8. The coatable composition as defined in claim 7, wherein the acrylate is selected from the group consisting of monofunctional acrylates, difunctional acrylates, trifunctional acrylates, acrylates of higher functionality and combinations of the foregoing.

9. The coatable composition as defined in claim 8, wherein the monofunctional acrylates are selected from the group consisting of tetrahydrofurfuryl acrylate, cyclohexyl acrylate, n-hexyl acrylate, 2-ethoxyethyl acrylate, isodecyl acrylate, 2-methoxyethyl acrylate, 2-(2-ethoxyethoxy)ethyl acrylate, stearyl acrylate, lauryl acrylate, octyl acrylate, 2-phenoxyethyl acrylate, glycidyl acrylate, isobornyl acrylate, benzyl acrylate, tridecyl acrylate, caprolactone acrylate, ethoxylated nonylphenol acrylate, polypropylene glycol acrylate, and combinations of the foregoing.

10. The coatable composition as defined in claim 8, wherein the difunctional acrylates are selected from the group consisting of triethylene glycol diacrylate, ethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate, diethylene glycol diacrylate, hexanediol diacrylate, neopentyl glycol diacrylate, tripropylene glycol diacrylate, ethoxylated bisphenol A diacrylate, propoxylated neopentyl glycol diacrylate, and combinations of the foregoing.

11. The coatable composition as defined in claim 8, wherein the trifunctional acrylates are selected from the group consisting of trimethylolpropane triacrylate, tris(2-hydroxyethyl)isocyanurate triacrylate, ethoxylated trimethylolpropane triacrylate, pentaerythritol triacrylate, propoxylated trimethylolpropane triacrylate, propoxylated glyceryl triacrylate, and combinations of the foregoing.

12. The coatable composition as defined in claim 8, wherein the acrylates of higher functionality are selected from the group consisting of pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, ethoxylated pentaerythritol tetraacrylate, metallic acrylates and combinations of the foregoing.

13. The coatable composition of claim 12, wherein the metallic acrylates are one or both of zinc diacrylate and calcium diacrylate.

14. The coatable composition as defined in claim 7, wherein the acrylate is selected from the group consisting of acrylated oligomers, acrylated polymers, acrylated silicones and combinations of the foregoing.

15. The coatable composition as defined in claim 14, wherein the acrylated polymer is selected from the group consisting of polyurethane monoacrylates, polyurethane polyacrylates, polyester monoacrylates, polyester polyacrylates, polyamide monoacrylates, polyamide polyacrylates, polybutadiene monoacrylates, polybutadiene polyacrylates, and combinations of the foregoing.

16. The coatable composition as defined in any one of claims 5 to 15, wherein the second monomer is present within the composition in an amount between about 5% and about 90%
by weight.

17. The coatable composition as defined in any one of claims 5 to 16, wherein the photoinitiator comprises benzophenone and the amount of the photoinitiator in the composition is in an amount between about 2% and about 10%
by weight.

18. The coatable composition of any one of claims 5 to 17, further comprising silica particles modified with 3-mercaptopropyltrimethoxysilane.

19. A coating derived from the coatable composition of any one of claims 5 to 18.

20. A floor finishing system comprising:

the coatable composition as defined in any one of claims 5 to 18; and a primer composition.

21. The floor finishing system as defined in claim 20, wherein the primer comprises an acrylated latex having a solids content between about 2 and about 40% by weight.

22. A method for applying a protective coating to a substrate, comprising:

(A) applying a radiation curable coatable composition to a substrate, the composition comprising (i) a first monomer comprising (a) polyfunctional isocyanurate having at least three isocyanate groups reacted with (b) hydroxyalkyl acrylate or methacrylate and (c) tertiary amine alcohol in a molar ratio of a:b:c of about 1:1-2.5:0.5-2, wherein b + c is at least 3 and no greater than the total number of isocyanate groups of (a), (ii) a second monomer comprising a radiation curable material, and (iii) photoinitiator; and (B) hardening the composition to form a protective coating over the substrate by exposing the coatable composition to ultraviolet radiation.

23. The method as defined in claim 22, wherein the first monomer comprises a compound having the general formula R1 and R2 are H or CH3, R3 and R4 independently are straight, branched or cyclic alkyl groups having from 1 to 12 carbon atoms, or R3 and R4 together form a divalent cycloalkanediyl, oxacycloalkanediyl, or azacycloalkanediyl bridging group having from 2 to 12 carbon atoms, and Z1, Z2, Z3, Z4, Z5, and Z6 independently represent divalent groups having from 1 to 18 carbon atoms.

24. The method as defined in claim 23, further comprising, before step (A), applying a primer composition to the substrate and drying the primer composition to form a primer coat over the substrate.

25. The method as defined in claim 24, wherein the primer composition comprises an acrylated latex having a solids content between about 2 and about 40% by weight.

26. The method as defined in claim 22, wherein the polyfunctional isocyanurate is a trimer of hexamethylene diisocyanate or an allophanated trimer derived from the reaction of hexamethylene diisocyanate and butanol.

27. The method as defined in claim 22 or 26, wherein the tertiary amine alcohol is selected from the group consisting of acyclic tertiary dialkylamino alcohols having from 3 to 30 carbon atoms, alicyclic tertiary amino alcohols having from 3 to 30 carbon atoms, polyaminoalcohols having from 3 to 30 carbon atoms, aromatic amine alcohols and combinations of the foregoing.

28. The method as defined in claim 27, wherein the acyclic tertiary dialkylamino alcohols having from 3 to 30 carbon atoms are selected from the group consisting of N,N-dimethylaminoethanol, N,N-dimethylaminopropanol, N,N-dimethylaminobutanol, N,N-dimethylaminohexanol, N,N-dimethylaminododecanol, N,N-diethylaminoethanol, N,N-diethylaminopropanol, N,N-diethylaminobutanol, N-ethyl-N-methylaminopropanol, N-ethyl-N-hexylaminoethanol, and combinations of the foregoing.

29. The method as defined in claim 27, wherein the alicyclic tertiary amino alcohols having from 3 to 30 carbon atoms are selected from the group consisting of 2-aziridinylethanol, 2-azetidinylethanol, 2-piperidinoethanol, N-methyl-4-azacyclohexanol, and combinations of the foregoing.

30. The method as defined in claim 27, wherein the polyaminoalcohols having from 3 to 30 carbon atoms are selected from the group consisting of N-methylpiperazinoethanol, N-butylpiperazinoethanol, N-methylpiperazinobutanol, and combinations of the foregoing.

31. The method as defined in any one of claims 22 and 26 to 30, wherein the hydroxyalkyl acrylate is 2-hydroxyethyl acrylate.

32. The method as defined in any one of claims 22 to 31, wherein the second monomer further comprises an acrylate.

33. The method as defined in claim 32, wherein the acrylate is selected from the group consisting of monofunctional acrylates, difunctional acrylates, trifunctional acrylates, acrylates of higher functionality and combinations of the foregoing.

34. The method as defined in claim 33, wherein the monofunctional acrylates are selected from the group consisting of tetrahydrofurfuryl acrylate, cyclohexyl acrylate, n-hexyl acrylate, 2-ethoxyethyl acrylate, isodecyl acrylate, 2-methoxyethyl acrylate, 2-(2-ethoxyethoxy)ethyl acrylate, stearyl acrylate, lauryl acrylate, octyl acrylate, 2-phenoxyethyl acrylate, glycidyl acrylate, isobornyl acrylate, benzyl acrylate, tridecyl acrylate, caprolactone acrylate, ethoxylated nonylphenol acrylate, polypropylene glycol acrylate, and combinations of the foregoing.

35. The method as defined in claim 33, wherein the difunctional acrylates are selected from the group consisting of triethylene glycol diacrylate, ethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate, diethylene glycol diacrylate, hexanediol diacrylate, neopentyl glycol diacrylate, tripropylene glycol diacrylate, ethoxylated bisphenol A
diacrylate, propoxylated neopentyl glycol diacrylate, and combinations of the foregoing.

36. The method as defined in claim 33, wherein the trifunctional acrylates are selected from the group consisting of trimethylolpropane triacrylate, tris(2-hydroxyethyl)isocyanurate triacrylate, ethoxylated trimethylolpropane triacrylate, pentaerythritol triacrylate, propoxylated trimethylolpropane triacrylate, propoxylated glyceryl triacrylate, and combinations of the foregoing.

37. The method as defined in claim 33, wherein the acrylates of higher functionality are selected from the group consisting of pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, ethoxylated pentaerythritol tetraacrylate, metallic acrylates and combinations of the foregoing.

38. The method as defined in claim 37, wherein the metallic acrylates are one or both of zinc diacrylate and calcium diacrylate.

39. The method as defined in claim 32, wherein the acrylate is selected from the group consisting of acrylated oligomer, acrylated polymer, acrylated silicone and combinations of the foregoing.

40. The method as defined in claim 39, wherein the acrylated polymer is selected from the group consisting of polyurethane monoacrylates, polyurethane polyacrylates, polyester monoacrylates, polyester polyacrylates, polyamide monoacrylates, polyamide polyacrylates, polybutadiene monoacrylates, polybutadiene polyacrylates, and combinations of the foregoing.

41. The method as defined in any one of claims 22 to 40, wherein the second monomer is present within the coatable composition in an amount between about 5% and about 90% by weight.

42. The method as defined in any one of claims 22 to 41, wherein the photoinitiator comprises benzophenone combined with a carbazole derivative, the photoinitiator present in the radiation curable coatable composition in an amount between about 2% and about 10% by weight.

43. The method as defined in any one of claims 22 to 42, wherein hardening of the composition comprises exposing the radiation curable coatable composition to ultraviolet radiation for a period of less than about 30 seconds.

44. The method as defined in claim 43, wherein the ultraviolet radiation comprises a first band of wavelengths less than about 300 nm and a second band of wavelengths between about 300 and 400 nm and wherein the ultraviolet radiation is emitted from a source at an intensity of between about 5 and about 15 mW/cm2.

45. A substrate treated with the method as defined in any one of claims 22 to 44.