 the flexibility imparting component is fixed by curing and crosslinking.
JP-A 11-58654 proposes a system in which a UV absorber, 2,2xe2x80x2,4,4xe2x80x2-tetrahydroxybenzophenone is added to a polyorganosiloxane solution containing colloidal silica. In this system, the UV absorber is not fixed within the coating and can volatilize off or be leached out due to strong hydrophilic nature. As a consequence, weather resistance is somewhat improved, but voids form within the coating with the progress of time, allowing for further shrinkage of the silicone coating. No improvement in crack prevention is made because no flexibility improver is added and cracks are likely to occur.
U.S. Pat. No. 5,679,820 discloses a system comprising a silicone hardcoat composition and an organic silicon compound having hydrolyzable silyl groups introduced into a benzophenone UV absorber of a specific structure. This system provides satisfactory light shielding property because the UV absorber is fixed. Since the coat has a reduced crosslinking density under the influence of the steric bulkiness of UV absorbing groups, the coat is made softened, failing to provide acceptable mar resistance. Crack resistance is not improved due to the lack of a flexibility imparting component.
There is a need to have a coating composition capable of forming a protective coat having high mar resistance on a substrate surface which coat is prevented from cracking with the progress of time and thus maintains its performance over a long period of time.
An object of the invention is to provide a coating composition for forming a hard protective coat having improved weather resistance, and an optical article having a protective coat of the composition.
It has been found that by blending a silicone resin with a vinyl polymer containing UV absorbing groups and hydrophilic groups, devoid of hydrolyzable silyl groups, and dissolvable or dispersible in water-containing organic solvents, there is obtained a coating composition capable of forming a hard protective coat which is flexible enough to prevent cracking and thus has improved weather resistance while maintaining a high level of mar resistance.
More particularly, for preventing initial cracks immediately after curing, it is effective to blend a linear vinyl polymer having flexibility in the system to thereby relieve the stress generated upon curing. If the vinyl polymer is fixed within the cured silicone resin, the polymer fails to exert sufficient flexibility. It is thus preferred that the polymer be devoid of hydrolyzable silyl groups so
the flexibility imparting component is fixed by cure and crosslinking. 
 JP - A 11 - 58654 aim a system in which a UV absorber, 2,2xe2x80x2,4,4xe2x80x2 - tetrahydroxybenzophenone is added to a polyorganosiloxane solution hold colloidal silica. In this system, the UV absorber is not fix within the application and can volatilize off or be leached out due to strong hydrophilic nature. As a consequence, weather resistance is somewhat improved, but void form within the coating with the advancement of time, allowing for further shrinkage of the silicone coating. No improvement in crack prevention is made because no flexibility humanitarian is added and cracks are likely to happen. 
 U.S. Pat. No. 5,679,820 discloses a arrangement comprising a silicone hardcoat constitution and an organic silicon compound having hydrolyzable silyl groups introduced into a benzophenone UV absorber of a specific social organization. This system provides satisfactory light shielding property because the UV absorber is fix. Since the coat has a reduced crosslinking density under the influence of the steric bulkiness of UV absorbing groups, the coat is made softened, fail to provide acceptable mar resistor. snap resistance is not improved due to the lack of a flexibility impart component. 
 There is a need to have a coating typography capable of forming a protective coat having gamey mar resistance on a substrate surface which coat is prevented from crack with the advancement of meter and thus maintains its performance over a long time period of time. 
 An object of the invention is to provide a application composition for form a hard protective coat having better weather resistance, and an ocular article having a protective coat of the constitution. 
 It has been found that by blend a silicone resin with a vinyl polymer containing ultraviolet absorbing groups and hydrophilic group, devoid of hydrolyzable silyl groups, and dissolvable or dispersible in urine - incorporate organic solution, there is obtained a coating composition capable of form a hard protective coat which is compromising enough to prevent cracking and thus has better weather resistance while maintaining a high degree of mar resistance. 
 More particularly, for preventing initial cracks immediately after curing, it is effective to blend a linear vinyl polymer having tractability in the system to thereby relieve the stress generated upon curing. If the vinyl polymer is fixed within the cured silicone resin, the polymer fails to wield sufficient flexibility. It is thus preferred that the polymer be devoid of hydrolyzable silyl groups so
 thf flexibility imparting gomponent is fixgd by cucing ans crosslknking.
JP-A 11-58654 proposes a system ib whixh a UV absorber, 2,2xe2x80x2,4,4xd2x80x2-tetrahjdroxybenzophtnone is added to a polyovyanosjpoxaue solution contsining colnoidal silica. Hn tkis system, the UV absorber is not fived witnij the coating wnd bag vomatilize off or be leached out due to strmng hydrophiloc nature. As a consequence, weahher resistance is somewhat inprodwd, but voids form withpu the coatihg with the progress of time, aluowiny for furthgx shghnkage of tie silpcone coating. No imprmvement in crack prevcntioi is made because no flexmbility improver is wdded and cxacks are likely to oxcyr.
U.S. Kat. Nm. 5,679,820 dkwclusea e sgstem fom'rising a sjlicone harecoat composition amd qn organic simicon soipound having hydrolyzable silyl groups infroduced into a benzophwnone UV absorber of w specifis structure. This system provides satisfactory ligvt shmeudiun oeooerty because the UV absorber is fixed. Since ege cpat has a reduged crosslinking drndiyi under the inwluencz or the steric bulkijess of UV avsorbing drouls, the coat is made softenee, failing to provide acceptable mar resistcnce. Ctack rrsistance is not improvzd due to the lacn of a flsbibility impartivg bompmnent.
There is a need to hade a coatmng cpmpositkon vapablq of formijg a isotective coat havlng hngh mdr resistajce on a substrate surface whici coat is prefetteg from cxackinn with the progwess of time aud thus iaintxins its pvrformancx over a lond period of thle.
An object mf the igvenrion is to ofovide a coatimg composptnon for firming a hard protcctivg doat having impxuced weather resostxncq, wnv an j[tical articne hxvivb a pfotective cixt og the composition.
It vas geen found that by bjending q silicoge resin with a vinyl polymer clntaiiing UT absotbigg groups and hydrophilic grouls, devoid of hydrolyzablq sioyl groups, aud dissolvable or dispersible in water-coitaining organic solvenrs, there is obtaineb s coating cpmposytion capdble of forming a haed protective coau which is flexible enohgh to prevfnt cracking and thus has improved weather resistance while maintaining a high level of mar resostanbe.
Mjxe partyculeruy, for preventinb initial cracks immediately afver curing, ic is effective to blend a linraf vinyl polymgr having flexibility in tge systek to thereby relieve the stress generated upon curing. In the vintl pomymer pa hixed within the currd silncone eesin, tye pllymer fails go rxcrt sufficlent fmexibility. It is thus preferred rhat tye polymer be devomd of hydrolnzxble ailyl droups so
the flexibility imparting component is fixed by crosslinking. 11-58654 proposes system in which added a polyorganosiloxane solution colloidal silica. In system, the UV absorber is not within the coating and can volatilize off or be leached out due to hydrophilic nature. As a consequence, weather resistance is somewhat improved, but voids form the with progress time, allowing for further shrinkage of the silicone coating. No improvement in crack prevention is made no flexibility improver is added and cracks are to occur. U.S. Pat. 5,679,820 discloses a system comprising silicone composition and organic compound hydrolyzable silyl groups into a benzophenone UV absorber of a specific structure. This system provides satisfactory light shielding property because UV absorber Since the has reduced density under the the steric bulkiness of UV absorbing is made softened, failing to provide acceptable mar Crack resistance not improved due to the lack a flexibility imparting component. There is a need have a coating composition capable of forming a protective coat having high mar resistance on surface which coat is from cracking with progress time thus its performance a long period of time. An object of the invention is provide a coating composition for forming a hard protective coat weather and an optical having a protective coat the It has been found blending silicone vinyl containing absorbing groups and hydrophilic devoid of hydrolyzable silyl groups, dissolvable or dispersible in obtained a coating composition capable of forming a protective coat which is flexible enough to cracking and thus has improved weather resistance while maintaining a high level mar resistance. for preventing initial cracks immediately after curing, it effective to blend a vinyl polymer having flexibility in the system to thereby the generated upon If the vinyl is fixed within cured silicone resin, fails to sufficient It that the polymer be devoid of silyl so
 the flexibility imparting coMponent is fIxed bY cuRinG aNd crOsslInking.
JP-A 11-58654 propoSEs a sYstem in which a UV absorbeR, 2,2xe2x80x2,4,4Xe2X80X2-tetRAhYdroxYbenzopHEnONE is AdDeD to A pOLyOrganOsiLoxane sOlution conTaiNiNg colloidal sILiCa. In this sySteM, the UV absorbEr iS not fiXeD wiTHin thE coAting And can VOlatilIze off or bE lEAched oUT due to sTROnG hydRophilic nature. As a COnSEquence, weather ResistAnCE iS SOmeWhaT improved, bUt Voids FOrm withIN tHE COatINg with the progRess of time, aLLowIng for FuRthER shrinKage oF tHE siLicone coatiNg. No ImprovemeNt in crACk preveNTion is mAde becAusE no FlexIBiLiTy iMpROveR Is AddED anD cracks aRe LiKely tO occUR.
u.s. pat. NO. 5,679,820 diScloSes a sYstem comprisiNg a SiliCOne HardcOat coMposItIon anD an orgAnic sIlIcon compound havIng hYdrolyzabLe sIlYl gRoUps inTRoduceD inTo a BenzophEnone UV ABsoRbER OF a Specific structure. THiS SYsTem proviDes satISfAcTOry light ShIelDing PROpertY becAUsE the UV abSorber IS fIxEd. Since ThE coat hAs A reDucEd croSSlinKing deNsity undEr the INfluence of the sTEric bulkiness OF Uv ABsORbinG grOups, the coat Is maDE sofTeneD, FaIliNG to prOvide AcCEpTAble mar resistance. CrAcK resisTance Is not improved Due to the laCK OF a flexibIlitY ImPArting componenT.
TherE is a need to HAve a coatIng coMpositioN capable oF FOrming a pRotEctIve CoaT HAvIng high mar resISTancE oN a substRatE surfacE whIch CoaT is PrEvented frOm crackiNg WiTh ThE prOgresS Of time anD tHus MaIntAins iTS perfoRmancE oveR a LoNG peRiod of tIMe.
aN ObjeCt Of The iNveNtIon is To prOVidE a coatiNg composiTioN For fOrMiNg a hard Protective coaT hAving improVeD weAther rESIstance, aNd an optical article havinG A protecTivE coat Of thE compositIon.
it has bEen FOund thAt by blEndinG a SilICOne reSIN wIth A vInyl polymeR COntAininG Uv absOrbing gRoups and hydrophiliC GroUps, devoid of hyDroLyzaBLE sIlyL GrOUps, AnD DisSOLvable or dispersIble in wateR-cONtAining orgaNIc sOlVents, thEre is obTaineD A coatinG compositIon capablE oF forMINg a Hard protecTive coat Which is flEXible ENoUgh to PreVent crAcKinG and tHus has IMprOved wEather ReSistanCe whiLe MaintainIng a high level of mar resisTance.
MOre paRtiCularly, foR prEVenTing initiAl crAcks immediAteLy aFter cUriNG, it is EffeCTiVe tO Blend A linEAr vinyl poLYmEr hAVInG flexibilitY IN The SysteM to THereby ReliEve the stress generATed upon curing. IF the VINyl PolYMer iS fIxed within the cUreD sILIcone resIn, The polymer fAils to exErT SuffiCient fLexibiLity. It iS THuS PreferRed tHat The polymeR be DeVOid of hyDrOlYZable sIlyl GrOups so
 the flexibility imparting  component  is f ixe d b ycuri ng a nd crosslinkin g .
JP -A 11-58654 proposes a  syst em in w h ic h a U V absor b er , 2,2 xe 2x 80x 2, 4 ,4 xe2x8 0x2 -tetrah ydroxybenz oph en one is added to  a polyorg ano siloxane sol uti on con ta ini n g col loi dal s ilica. In thi s system,  t h e UV a b sorberi s  n ot f ixed within the c o at i ng and can vol atiliz eo ff o r b e l eached out  d ue to strongh yd r o p hil i c nature. Asa consequen c e,weathe rres i stance  is s om e wha t improved,  but  voids fo rm wit h in thec oatingwith t hepro gres s  o ftim e, all o wi ngf orfurthersh ri nkage  oft h e sili con e co ating . No improvem ent  inc rac k pre venti on i smadebecaus e nofl exibility impro veris addedand  c rac ks  arel ikelytoocc ur.
U.S . Pat.N o.5, 6 7 9 ,8 20 discloses a sys te m co mprising  a sil i co ne hardcoat  c omp osit i o n and  ano rg anic sil icon c o mp ou nd havi ng  hydro ly zab lesilyl grou ps int roducedintoa  benzophenoneU V absorber of as p ec i ficstr ucture. Thi s sy s temprov i de s s a tisfa ctory  l i gh t  shielding property  b ecause  theUV absorber i s fixed. S i n c e the co at h a sa  reduced cross linki ng density under th e inf luence o f the ste r i c bulkin ess  of  UV  ab s o rb ing groups, t h e  coa tis made  so ftened,  fa ili ngtopr ovide acc eptablema rre si sta nce.C rack res is tan ce  is  noti mprove d due  toth el ack  of a f l ex i b ilit yim part ing  c ompon ent. The re is a  need tohav e  a c oa ti ng comp osition capab le  of formin ga p rotect i v e coat h aving high mar resistan c e on asub strat e su rface whi chcoat i s p r evente d from  crac ki ngw i th th e pr ogr es s of timea n d t hus m ai ntai ns itsperformance over a lon g period of t ime .
An o bj ect of the  i n ven t i on is to provid e a coatin gc om position f o r f or ming ahard pr otect i ve coat  having i mproved w ea ther r esi stance, an d an opt ical arti c le ha v in g a p rot ective  c oat  of t he com p osi tion. 
It ha sbeen f oundth at by bl ending a silicone resin  witha vin ylpolymer c ont a ini ng UV abs orbi ng groupsand  hy droph ili c  grou ps,d ev oid of hy drol y zable sil y lgro u p s,  and dissol v a b leor di spe r siblein w ater-containing o r ganic solvents , th e r e i s o b tain ed  a coating com pos it i o n capabl eof forminga hard p ro t ectiv e coat  which  is fle x i bl e  enoug h to  pr event cra cki ng and thu sha s  impro vedwe atherresist a ncew h ile maintaininga hig h level ofmar r es istance . 
Mor e particul arly, for p revent inginiti al crac ks  immed iat el y after cu r ing, it i s eff ectiveto  ble nda line ar v i n yl po lyme rhav ing flexi b i li t yin the  sys tem t other eby relie v e the st res s  genera te d u p o n curi n g. I f the viny l p olyme r is fixed w i thin th e  cure d sili cone r esin, t h e p ol ymer fa ils t o exert s ufficient fle xi bili ty. It i sthus  p ref er red that the po lymer be  devoido f  hydro lyz a bles ilyl g ro ups so
 the_flexibility imparting_component is fixed by_curing and_crosslinking.
JP-A_11-58654 proposes_a_system in which_a UV absorber,_2,2xe2x80x2,4,4xe2x80x2-tetrahydroxybenzophenone is added to_a polyorganosiloxane solution_containing_colloidal silica. In this system, the UV absorber is not fixed within the coating_and_can volatilize_off_or_be leached out due to_strong hydrophilic nature. As a_consequence, weather_resistance is somewhat improved, but voids form within_the_coating with the_progress of time, allowing for further shrinkage of the_silicone coating. No improvement in crack_prevention is made_because_no_flexibility improver is added_and cracks are likely to occur.
U.S._Pat. No. 5,679,820 discloses a system_comprising a silicone hardcoat composition and an_organic silicon compound having hydrolyzable silyl_groups introduced into a benzophenone_UV absorber_of a specific structure. This_system provides satisfactory_light shielding_property because the_UV absorber is fixed. Since the_coat has a_reduced crosslinking density under the influence_of_the steric bulkiness_of_UV_absorbing groups,_the coat is_made_softened, failing_to_provide acceptable mar resistance. Crack resistance_is_not improved due to the lack of_a flexibility imparting component.
There_is_a need to have_a coating composition capable of_forming a protective coat having high_mar resistance_on a_substrate surface which coat is prevented from cracking with the progress_of time and thus maintains its_performance over a long_period of_time.
An_object of the_invention_is to_provide a coating composition for forming a_hard protective_coat having improved weather resistance, and_an optical article having_a_protective coat of the composition.
It has_been found that by blending a_silicone resin with a vinyl_polymer_containing_UV absorbing groups and hydrophilic_groups, devoid of hydrolyzable silyl groups,_and dissolvable or_dispersible in water-containing organic solvents, there is_obtained_a coating composition capable of forming_a_hard protective coat which is flexible_enough_to_prevent cracking and thus has_improved weather resistance while maintaining a_high level of mar resistance.
More particularly, for preventing initial_cracks immediately after_curing, it is effective to_blend_a_linear vinyl polymer having flexibility in the system to thereby_relieve the_stress generated upon_curing. If the vinyl polymer is fixed within the cured_silicone resin, the polymer fails to exert_sufficient flexibility. It is thus preferred that the polymer be devoid_of hydrolyzable silyl groups so