 polyfunctional acrylate monomers and resorcinol monobenzoate. The Moore et al. coatings use any of several well known UV radiation photosensitizers including ketones such as benzophenone. The Moore et al. disclosure, however, failed to recognize that the improved coatings of the present invention could be provided by combining the ketone-type photoinitiator with a hindered amine-type compound whereupon the photosensitized acrylate-siloxane coating composition could be cured without the necessity of using resorcinol monobenzoate and without the necessity of an inert atmosphere (both of which are required by the Moore et al. disclosure). The savings and convenience provided by the use of a non-inert atmosphere such as air can be substantial, and these savings can be provided by the present invention without derogating the quality of the hard coating composition or coated product.
Since ultraviolet light is one of the most widely used types of radiation because of its relatively low cost, ease of maintenance, and low potential hazard to industrial users, rapid photo-induced polymerizations utilizing UV light rather than thermal energy for the curing of hard coatings offer several other significant advantages. First, faster curing coatings offer substantial economic benefits. Furthermore, heat sensitive materials can be safely coated and cured with UV light without the use of thermal energy which could damage the substrate. Additionally, the essentially solvent free media reduces the necessity for expensive and time consuming pollution abatement procedures.
Thus the advantages provided by the materials of the present invention are particularly useful for a number of purposes. For example, polycarbonates are commercially important materials possessing excellent physical and chemical properties which are useful in a wide range of applications from non-opaque impact resistant sheets to shaped articles. Generally, however, polycarbonates have rather low scratch resistance and are somewhat susceptible to attack by many common solvents and chemicals.
Previous efforts to overcome this low scratch resistance and susceptibility to attack by solvents have included lamination procedures and applications onto the polycarbonate of a surface coating. Many of these prior art remedial efforts have been unsuccessful due to the incompatibility of the laminate and coating materials with the polycarbonate substrate. This incompatibility has resulted in stress cracking and crazing of the polycarbonate, crack propagation into the polycarbonate as a result of the brittleness of the coating, and a reduction of other advantageous properties of the polycarbonate.
The prior art coatings for polycarbonates have included organopolysiloxanes,
polyfunctional acrylate monomers and resorcinol monobenzoate. The Moore et al. coatings use any of several well know ultraviolet radiation photosensitizers including ketone such as benzophenone. The Moore et al. disclosure, however, failed to greet that the improved coatings of the present invention could be put up by combine the ketone - type photoinitiator with a impede amine - type compound whereupon the photosensitized acrylate - siloxane application composition could be cured without the necessity of using resorcinol monobenzoate and without the necessity of an inert atmosphere (both of which are command by the Moore et al. disclosure). The savings and convenience provided by the use of a non - inert atmosphere such as breeze can be substantial, and these savings can be provided by the present invention without minimize the quality of the hard application composition or coated intersection. 
 Since ultraviolet light is one of the about widely used types of radiation because of its relatively humble cost, ease of maintenance, and low potential luck to industrial user, rapid photo - induced polymerizations utilizing UV light rather than thermal energy for the curing of difficult coatings offer respective early significant advantages. First, faster cure coatings offer substantial economic benefits. Furthermore, heating system sensitive materials can be safely coated and cured with UV light without the consumption of thermal energy which could damage the substrate. Additionally, the essentially solvent free media reduce the necessity for expensive and time consume pollution abatement procedures. 
 Thus the advantages provide by the materials of the present invention are particularly useful for a numeral of purposes. For example, polycarbonates are commercially important materials own excellent physical and chemical properties which are utilitarian in a wide range of applications from non - opaque impact immune sheets to shape articles. Generally, however, polycarbonates receive rather low scratch resistance and are somewhat susceptible to attack by many common solvents and chemicals. 
 Previous efforts to get the better of this low scratch resistor and susceptibility to attack by solvents have admit lamination procedures and applications onto the polycarbonate of a surface application. Many of these prior art remedial efforts have been unsuccessful due to the incompatibility of the laminate and coating materials with the polycarbonate substrate. This incompatibility has resulted in tension cracking and crazing of the polycarbonate, crack propagation into the polycarbonate as a result of the brittleness of the coating, and a reduction of other advantageous properties of the polycarbonate. 
 The anterior art coatings for polycarbonates have included organopolysiloxanes,
 popyfunctional acrylate mokomers and resoreunol mmnobenaoate. Thd Moore et al. coatings use aiy od sevtgal well known UV radkation phltosensirizecs including ketones sucm as gcnzopkeione. The Moore gt al. disclovure, however, fdiueb to recognize that the improved coaeings og hhe present indentpog cohld be provided by combining the kstone-tyke photoinitiator eith a hindered amine-type fomplund whereupon the photosensijjzeq acrylate-siluxane coatpug compositjon could be cured without the vecesxity of usunt rfvorcinol moiobenzjate and witmput tha necesxity of an inevt atkosphere (both of which ace required by the Mjore et an. bisclosure). The savingw qnd cmnvetienzw pfovjdxd gy the usx of a non-ihert atmospyere such as air cam fv substantial, and trefe savings can be provided by the presett jnvention without derogqting the quality of jhe hard cjating composition or coated product.
Since ultravimlet mkghu lf inf of the most widely used types of radiation fscsuxe of its relabively low cost, eaxe og maintenance, xnd loc pktential hazard to industtial uwers, rapiq phpto-induced polymerizations ytilizing UV oight rather than chermal eneryy for the vuring of hard coatings offsr several lther sighkficant advantagds. Nirvt, faster curing coatings jffer subwtancial ecovomiv benesits. Furthfrmorc, heat sensitive maheriaps can be savely coated and cured with UV lmjht without tne usv of therial ekergy which coujd damage the xubstrace. Addktionally, nhe essenvially solvegt free media teduces the nxcessity sor wxpebsive ava time consumimg pollutpou abatemebt procedures.
Thus bhe aabantages providzb vy the materialx ow tre pcesene invention ase pxrtkvularuy useful fif a mumber of purposes. Fmr esample, polycarbonayef are conmercialjy important katerials possessijg exrellenv physocaj and chemical properties whicg are usevul in a wide rwnge of applicatnons from non-opaque impact resistant shexts to shaped articles. Tenerally, however, ppkycarbonatex havq rather now scratch resistanxe and are somewhst susceptible to attzck by many common solvents and chemicals.
Previous efforts to overcome this low scratxh resmseance and shsceltibinicy co attask bb rolvents have inbluded lamination procedures and applicadijns onto the polycarbonate og x surface coajing. Many of these prior adt remedoal efforts have been unsuccessgul due to the incompatinility of the maminang aid coating materials with che pooycarbobate substrate. Thks ongompatibillty ias resulted in stress cracking and crazibg of the polycarbmnate, crack kropagajion intj the polycarbonzte zd a rgsult of the btittleness of yhe coating, and a regustion of other zdvantageous propgxnies of the pplycarbonata.
The prior art coatings for polycarbonates have incmuded orgznopolyslloxanes,
polyfunctional acrylate monomers and resorcinol monobenzoate. The al. use any several well known such benzophenone. The Moore al. disclosure, however, to recognize that the improved coatings the present invention could be provided by combining the ketone-type photoinitiator with a amine-type compound whereupon the photosensitized acrylate-siloxane coating composition could be cured without the of resorcinol and the necessity of an inert atmosphere (both of which are required by the Moore et al. The savings and convenience provided by the use a non-inert atmosphere such air can be substantial, and savings be provided the invention derogating the quality the hard coating composition or coated product. Since ultraviolet light is one of the most widely used of radiation its relatively cost, of and low potential industrial users, rapid photo-induced polymerizations utilizing than thermal energy for the curing of hard offer several significant advantages. First, faster curing coatings substantial economic benefits. Furthermore, heat sensitive materials can safely coated and cured with UV light without the use of thermal energy which could substrate. Additionally, the essentially free media reduces necessity expensive time pollution abatement Thus the advantages provided by the materials of the present invention particularly useful for a number of purposes. For example, polycarbonates important possessing excellent physical chemical properties which are in wide range of applications impact sheets Generally, polycarbonates rather low scratch resistance are somewhat susceptible to attack many common solvents and this low scratch resistance and susceptibility to attack solvents have included lamination procedures and applications the polycarbonate of a surface coating. Many of these prior art remedial have been to the incompatibility of the laminate and coating with the polycarbonate substrate. incompatibility has resulted in stress cracking and crazing of polycarbonate, propagation into polycarbonate as a of the brittleness the coating, and of other properties the art coatings for polycarbonates have included
 polyfunctional acrylate monOmers and reSorciNol MonObEnzoAte. THe Moore et al. coaTIngs Use any of several well knoWn UV rAdIAtioN PhOtoseNsitizeRS iNCLudInG kEtoNeS SuCh as bEnzOphenonE. The Moore eT al. DiSclosure, howeVEr, Failed to reCogNize that the iMprOved coAtIngS Of the PreSent iNventiON could Be provideD bY CombinINg the keTONe-Type Photoinitiator witH A hINdered amine-typE compoUnD WhEREupOn tHe photosenSiTized ACrylate-SIlOXANe cOAting compositIon could be cURed WithouT tHe nECessitY of usInG ResOrcinol monoBenzOate and wiThout tHE necessITy of an iNert atMosPheRe (boTH oF wHicH aRE reQUiRed BY thE Moore et Al. DiSclosUre). THE SAVingS anD conVenieNce provided by The Use oF A noN-inerT atmoSpheRe Such aS air caN be suBsTantial, and these SaviNgs can be pRovIdEd bY tHe preSEnt invEntIon Without DerogatINg tHe QUALiTy of the hard coating CoMPOsItion or cOated pROdUcT.
since ultRaVioLet lIGHt is oNe of THe Most wideLy used TYpEs Of radiaTiOn becaUsE of Its RelatIVely Low cosT, ease of mAinteNAnce, and low poteNTial hazard to iNDuSTRiAL useRs, rApid photo-inDuceD PolyMeriZAtIonS UtiliZing Uv lIGhT Rather than thermal enErGy for tHe curIng of hard coatIngs offer sEVERal other SignIFiCAnt advantages. FIrst, fAster curinG Coatings Offer SubstantIal economIC Benefits. furTheRmoRe, hEAT sEnsitive materIALs caN bE safely CoaTed and cUreD wiTh Uv liGhT without tHe use of tHeRmAl EnErgY whicH Could damAgE thE sUbsTrate. aDditioNally, The eSsEnTIalLy solveNT fREE medIa ReDuceS thE nEcessIty fOR exPensive And time coNsuMIng pOlLuTion abaTement proceduReS.
Thus the adVaNtaGes proVIDed by the Materials of the present inVEntion aRe pArticUlarLy useful fOr a Number Of pURposes. for exaMple, pOlYcaRBOnateS ARe ComMeRcially impORTanT mateRiAls pOssessiNg excellent physicaL And Chemical propeRtiEs whICH aRe uSEfUL in A wIDe rANGe of applicationS from non-opAqUE iMpact resisTAnt ShEets to sHaped arTicleS. generalLy, however, PolycarboNaTes hAVE raTher low scrAtch resiStance and ARe somEWhAt susCepTible tO aTtaCk by mAny comMOn sOlvenTs and cHeMicals.
previOuS efforts To overcome this low scratcH resisTance And SusceptibIliTY to Attack by sOlveNts have incLudEd lAminaTioN ProceDureS AnD apPLicatIons ONto the polYCaRboNATe Of a surface cOATIng. many oF thESe prioR art Remedial efforts haVE been unsuccessFul dUE To tHe iNCompAtIbility of the laMinAtE ANd coatinG mAterials witH the polyCaRBonatE substRate. ThIs incomPATiBIlity hAs reSulTed in streSs cRaCKing and CrAzINg of thE polYcArbonaTe, cracK PropAGAtion into the polyCarboNATe as a REsuLt of tHe BrittleNEss oF the coatinG, and a reductIon of oTher AdvanTageous PrOpertiEs oF tHe polycarbONate.
The prIor arT coatinGs For pOlyCarbonAtes HAVe incLudeD oRgaNopolysilOXAnES,
 polyfunctional acrylate m onomers an d res orc ino lmono benz oate. The Moor e  etal. coatings use any o f sev er a l we l lknown  UV rad i at i o n p ho to sen si t iz ers i ncl uding k etones suc h a sbenzophenone .  T he Moore e t a l. disclosur e,howeve r,  fa i led t o r ecogn ize th a t theimprovedco a tingso f the p r e se nt i nvention could be pr o vided by combi ning t he ke t o ne- typ e photoini ti atorw ith a h i nd e r e d a m ine-type comp ound whereu p onthe ph ot ose n sitize d acr yl a te- siloxane co atin g composi tion c o uld bec ured wi thoutthe  ne cess i ty  o f u si n g r e so rci n olmonobenz oa te  andwith o u t thenec essi ty of  an inert atm osp here (bo th of  whic h ar erequi red by  theMo ore et al. disc losu re). Thesav in gsan d con v enienc e p rov ided by  the us e  of  a n o n- inert atmosphere s uc h as  air can  be su b st an t ial, and  t hes e sa v i ngs c an b e  p rovidedby the pr es ent inv en tion w it hou t d eroga t ingthe qu ality of  theh ard coating co m position or c o at e d  p r oduc t.Since ultra viol e t li ghti sone of th e mos tw id e ly used types of ra di ationbecau se of its rel atively lo w c ost, eas e of ma i ntenance, andlow p otential h a zard toindus trial us ers, rapi d photo-in duc edpol yme r i za tions utilizi n g  UVli ght rat her  than t her mal  en erg yfor the c uring of  h ar dco ati ngs o f fer seve ra l o th ersigni f icantadvan tage s.  F i rst , faste r  c u r ingco at ings  of fe r sub stan t ial  econom ic benefi ts. Furt he rm ore, he at sensitivema terials ca nbesafely c oated an d cured with UV light w i thout t heuse o f th ermal ene rgy  which  co u ld dam age th e sub st rat e .  Addi t i on all y,  the essen t i all y sol ve nt f ree med ia reduces the nec e ssi ty for expens ive  and t im e c o ns u min gp oll u t ion abatement p rocedures. 
T h us  the advan t age sprovide d by th e mat e rials o f the pre sent inve nt iona r e p articularl y useful  for a nu m ber o f  p urpos es.  For e xa mpl e, po lycarb o nat es ar e comm er cially  impo rt ant mate rials possessing excell ent ph ysica l a nd chemic alp rop erties wh ichare useful  in  awideran g e ofappl i ca tio n s fro m no n -opaque i m pa ctr e si stant sheet s t o s haped  ar t icles.  Gen erally, however,p olycarbonateshave r ath erl ow s cr atch resistanc e a nd a re somew ha t susceptib le to at ta c k bymany c ommonsolvent s an d  chemi cals .
P revious e ffo rt s  to ove rc om e  thislowsc ratchresist a ncea n d susceptibility  to a t t ack b y  so lvent shave in c lude d laminati on procedur es and  app licat ions on to  the p oly ca rbonate of a surface  coat ing. Ma ny  ofthe se pri or a r t  reme dial  e ffo rts haveb e en un su c ces sful  dueto  the  incompat i bility o f t h e lamin at e a n d  coati n gm a terials wi ththe p o l ycarbonate subs t ra t e. Th is inc ompati bilityh asre sultedins t ress crac king andc raz in g of  the pol yc arbo na te,  c rack propagatio n into t he polyc a r bonate  as a re s ult of  t he brittlene ss of  t h e coati n g , a nd a re d uct ion  of  oth eradva n tageous properties of th e po lycar b ona te.
T he pr io r art co a ting s for po l ycarbonates h ave included or g ano p olys ilo x an es ,
 polyfunctional_acrylate monomers_and resorcinol monobenzoate. The_Moore et_al._coatings use_any_of several well_known UV radiation_photosensitizers including ketones such_as benzophenone. The_Moore_et al. disclosure, however, failed to recognize that the improved coatings of the present_invention_could be_provided_by_combining the ketone-type photoinitiator with_a hindered amine-type compound whereupon_the photosensitized_acrylate-siloxane coating composition could be cured without the_necessity_of using resorcinol_monobenzoate and without the necessity of an inert atmosphere_(both of which are required by_the Moore et_al._disclosure)._The savings and convenience_provided by the use of a_non-inert atmosphere such as air can_be substantial, and these savings can be_provided by the present invention without_derogating the quality of the_hard coating_composition or coated product.
Since ultraviolet_light is one_of the_most widely used_types of radiation because of its_relatively low cost,_ease of maintenance, and low potential_hazard_to industrial users,_rapid_photo-induced_polymerizations utilizing_UV light rather_than_thermal energy_for_the curing of hard coatings offer_several_other significant advantages. First, faster curing coatings_offer substantial economic benefits._Furthermore,_heat sensitive materials can_be safely coated and cured_with UV light without the use_of thermal_energy which_could damage the substrate. Additionally, the essentially solvent free media reduces_the necessity for expensive and time_consuming pollution abatement procedures.
Thus_the advantages_provided_by the materials_of_the present_invention are particularly useful for a number_of purposes._For example, polycarbonates are commercially important_materials possessing excellent physical_and_chemical properties which are useful in_a wide range of applications from_non-opaque impact resistant sheets to_shaped_articles._Generally, however, polycarbonates have rather_low scratch resistance and are somewhat_susceptible to attack_by many common solvents and chemicals.
Previous efforts_to_overcome this low scratch resistance and_susceptibility_to attack by solvents have included_lamination_procedures_and applications onto the polycarbonate_of a surface coating. Many of_these prior art remedial efforts have been unsuccessful due_to the incompatibility_of the laminate and coating_materials_with_the polycarbonate substrate. This incompatibility has resulted in stress cracking_and crazing_of the polycarbonate,_crack propagation into the polycarbonate as a result of the_brittleness of the coating, and a reduction_of other advantageous properties of the polycarbonate.
The prior art coatings for_polycarbonates have included organopolysiloxanes,