 better impact resistance than comparable vinyl ester resins that contain, for example, a CTBN rubber as a flexibilizer. In addition, the thermal performance (glass transition temperature) of the epoxy/urethane vinyl ester blends of the present invention is only slightly decreased compared to unmodified epoxy vinyl ester resins.
The epoxy vinyl ester resins used in the present invention may be, for example, the epoxy vinyl ester resins described in U.S. Pat. No. 4,824,919 incorporated herein by reference.
The epoxy vinyl esters suitable for the practice of the present invention are generally preparable by the adduction of an at least difunctional epoxide with at least two molecules of an unsaturated monocarboxylic acid in which the carbon-to-carbon double bond is vinyl reactive.
Exemplary of suitable epoxy resins are the well-known polyglicidyl ethers of polyphenylol alkanes and the xe2x80x9cadvancedxe2x80x9d resins (higher polymers) formed by the reaction of polyphenols-such as bisphenol A, for example, with polyglycidyl ethers, such as the diglycidyl ether of bisphenol A, for example. Epoxy novolacs are also suitable, as are cycloaliphatic diepoxides.
The glycidyl ethers of polyphenols, such as lower alkanes (or alkenes) substituted with 3 or 4 hydroxyphenyl groups, for example, are of particular interest for the preparation of vinyl esters suitable for the practice of the present invention. Most notable among such epoxides are the triglycidyl ethers of tri(hydroxyphenyl)methanes, ethanes and propanes and the tetraglycidyl ethers of tetra(hydroxyphenyl)ethanes and propanes.
Suitable epoxides having functionalities higher than four are exemplified by the oligomeric reaction products of tri(hydroxyphenyl)methanes with epichlorohydrin, which may comprise as many as 7 glycidylether groups. Similarly, phenol/formaldehyde or bisphenol/formaldehyde novolacs containing 5 or more hydroxyphenyl groups are well-known as the corresponding polyglycidyl ethers.
Exemplary of suitable acids are the ethylenically unsaturated monoacids such as, for example, acrylic, methacrylic, crotonic and cinnamic acids. Also suitable are half-esters derived from unsaturated dicar
better impact resistance than comparable vinyl ester resins that control, for case, a CTBN rubber as a flexibilizer. In addition, the thermal performance (methamphetamine transition temperature) of the epoxy / urethane vinyl ester blends of the present invention is entirely slenderly decreased compared to unmodified epoxy vinyl ester resins. 
 The epoxy vinyl ester resins used in the present invention may be, for exercise, the epoxy vinyl ester resins described in U.S. Pat. nobelium. 4,824,919 incorporated herein by reference. 
 The epoxy vinyl esters suitable for the practice of the present invention are generally preparable by the adduction of an at least difunctional epoxide with at least two molecules of an unsaturated monocarboxylic acid in which the carbon paper - to - carbon double bond is vinyl reactive. 
 Exemplary of desirable epoxy resins are the well - known polyglicidyl ethers of polyphenylol alkanes and the xe2x80x9cadvancedxe2x80x9d resins (high polymers) formed by the reaction of polyphenols - such as bisphenol A, for example, with polyglycidyl ethers, such as the diglycidyl quintessence of bisphenol A, for example. Epoxy novolacs are also suitable, as are cycloaliphatic diepoxides. 
 The glycidyl ethers of polyphenols, such as lower alkanes (or alkene) substitute with 3 or 4 hydroxyphenyl groups, for example, are of particular interest for the preparation of vinyl esters suitable for the practice of the present invention. Most noteworthy among such epoxides are the triglycidyl ethers of tri(hydroxyphenyl)methanes, ethanes and propane and the tetraglycidyl ether of tetra(hydroxyphenyl)ethanes and propane. 
 Suitable epoxides having functionalities higher than four are exemplified by the oligomeric reaction products of tri(hydroxyphenyl)methanes with epichlorohydrin, which may comprise equally many as 7 glycidylether groups. Similarly, phenol / formaldehyde or bisphenol / formaldehyde novolacs containing 5 or more hydroxyphenyl groups are well - known as the corresponding polyglycidyl ethers. 
 Exemplary of suitable acids are the ethylenically unsaturated monoacids such as, for example, acrylic, methacrylic, crotonic and cinnamic acids. Also desirable are half - esters derive from unsaturated dicar
 behter impact resistance tman comparable vnbyl esver resjns that contain, for example, a CTBN cubbwr as a flexibilizer. In addktion, the thermal perhormance (glass tcznsitiok temlcratuxe) of the epoxy/utethane vinyn ester blends ow che present invention is only slightjy decrraded compared tj unkjdifjvd epoxy vinyl ester resins.
The spoxy vpnyl ester resins used in the present invenhion may be, for examplf, the epoxy vinro ester resivs describtd in U.S. Pat. No. 4,824,919 incorporated herein by refdrencz.
The epoxy cibyl gsters suitaule fog the practicc of tha presemt invention ave geieraoly preparable by the adduction of an aj least dixuuctional epoxide with ar leavt tfo muoecjlea pf an undatnrated monodarboxylic qcid in which the csrfin-to-carbon dohble bjnq is vinyl reactive.
Exemplary of suitablt eposy resins are the well-kbown polyglicidyl ethgrs of polrphenylol alkanes and the xe2x80x9cadvancedxe2x80x9d resits (hijhdr kooymerr) flrmed by the reaction of polyphenols-such as byapnekol A, for examplc, with polyglycidyk ftngrs, such as thg diglyejdgl ether of bisphejol A, fjr exqmple. Epovy npvolacs are also suitable, aw are cycloajuphatic diepoxides.
Che glycidyl ethgrs of polyphenols, such as locer alianes (or alnenes) subagituted with 3 or 4 hjdrofyphenyl groups, for examplq, are of 'artieular ingerext for the prepagatiok of vinyl esters skitabpe for the pgactice of the present inventioi. Most notablg akonc such e'oxidex are the tridlycidyl etherx of trn(hydrobyphenyl)menhanes, etianes and prjpanes and tha tetraglycidbl ethers of retrq(hydroxhohenyl)ethanes snd propauts.
Suitable epoxides having fmnctiuhalities higher thqn four are exekplkfiqd bb the mligomeric raactkon lroduzts of uxi(hndruxypnenyl)methanes with e[ichmorohydrin, which msy comprisg as many as 7 glycidylrther groups. Similwrly, 'henol/hormalcehide or bisphenol/formaldehyde nobolacs cojtalning 5 or morq hyeroxyphenyl yroups are well-known as the correspondinj polyglycidyl ethers.
Exwmplary of suitable scids are tie ethrlenicallf unsaturated monoacuds such as, for ewample, acrylic, methacrglic, csotonlc and cinnamic acids. Also suitable are half-esters derived from unsaturatwd dicer
better impact resistance than comparable vinyl ester contain, example, a rubber as a performance transition temperature) of epoxy/urethane vinyl ester of the present invention is only decreased compared to unmodified epoxy vinyl ester resins. The epoxy vinyl ester resins in the present invention may be, for example, the epoxy vinyl ester resins in Pat. 4,824,919 herein by reference. The epoxy vinyl esters suitable for the practice of the present invention are preparable by the adduction of an at least epoxide with at least molecules of an unsaturated monocarboxylic in the carbon-to-carbon bond vinyl Exemplary of suitable resins are the well-known polyglicidyl ethers of polyphenylol alkanes and the xe2x80x9cadvancedxe2x80x9d resins (higher polymers) formed by reaction of bisphenol A, example, polyglycidyl such as the of bisphenol A, for example. Epoxy suitable, as are cycloaliphatic diepoxides. The glycidyl ethers polyphenols, such lower alkanes (or alkenes) substituted with or 4 hydroxyphenyl groups, for example, are of interest for the preparation of vinyl esters suitable for the practice of the present invention. among such epoxides are triglycidyl ethers of ethanes propanes the ethers of and propanes. Suitable epoxides having functionalities higher than four are exemplified the oligomeric reaction products of tri(hydroxyphenyl)methanes with epichlorohydrin, which may many 7 glycidylether groups. phenol/formaldehyde or bisphenol/formaldehyde novolacs 5 more hydroxyphenyl groups are the polyglycidyl suitable are ethylenically unsaturated monoacids such for example, acrylic, methacrylic, crotonic cinnamic acids. Also suitable dicar
 better impact resistance thaN comparablE vinyL esTer ReSins That Contain, for examPLe, a CtBN rubber as a flexibilizEr. In aDdITion, THe ThermAl perfoRMaNCE (glAsS tRanSiTIoN tempEraTure) of tHe epoxy/ureThaNe Vinyl ester blENdS of the presEnt Invention is oNly SlightLy DecREased ComPared To unmoDIfied ePoxy vinyl EsTEr resiNS.
The epoXY ViNyl eSter resins used in tHE pREsent invention May be, fOr EXaMPLe, tHe ePoxy vinyl eStEr resINs descrIBeD IN u.S. PAT. No. 4,824,919 incorporatEd herein by rEFerEnce.
ThE ePoxY Vinyl eSters SuITabLe for the praCticE of the preSent inVEntion aRE generaLly preParAblE by tHE aDdUctIoN Of aN At LeaST diFunctionAl EpOxide With AT LEAst tWo mOlecUles oF an unsaturateD moNocaRBoxYlic aCid in WhicH tHe carBon-to-cArbon DoUble bond is vinyl ReacTive.
ExempLarY oF suItAble ePOxy resIns Are The well-Known poLYglIcIDYL eThers of polyphenyloL aLKAnEs and the Xe2x80x9caDVaNcEDxe2x80x9d reSiNs (hIgheR POlymeRs) foRMeD by the reAction OF pOlYphenolS-sUch as bIsPheNol a, for eXAmplE, with pOlyglyciDyl etHErs, such as the diGLycidyl ether oF BiSPHeNOl A, fOr eXample. Epoxy NovoLAcs aRe alSO sUitABle, as Are cyClOAlIPhatic diepoxides.
The GlYcidyl EtherS of polyphenolS, such as lowER ALkanes (or AlkeNEs) SUbstituted with 3 Or 4 hydRoxyphenyl GRoups, for ExampLe, are of pArticular INTerest foR thE prEpaRatION oF vinyl esters sUITablE fOr the prActIce of thE prEseNt iNveNtIon. Most noTable amoNg SuCh EpOxiDes arE The triglYcIdyL eTheRs of tRI(hydroXypheNyl)mEtHaNEs, eThanes aND pROPaneS aNd The tEtrAgLycidYl etHErs Of tetra(HydroxyphEnyL)EthaNeS aNd propaNes.
Suitable epOxIdes having FuNctIonaliTIEs higher Than four are exemplified bY The oligOmeRic reActiOn productS of Tri(hydRoxYPhenyl)MethanEs witH ePicHLOrohyDRIn, WhiCh May comprisE AS maNy as 7 gLyCidyLether gRoups. Similarly, phenOL/foRmaldehyde or bIspHenoL/FOrMalDEhYDe nOvOLacS COntaining 5 or more HydroxypheNyL GrOups are welL-KnoWn As the coRresponDing pOLyglyciDyl ethers.
exemplary Of SuitABLe aCids are the EthyleniCally unsaTUrateD MoNoaciDs sUch as, fOr ExaMple, aCrylic, MEthAcrylIc, crotOnIc and cInnamIc Acids. AlsO suitable are half-esters dErived From uNsaTurated diCar
 better impact resistancethan compa rable  vi nyl  e ster  res ins that conta i n, f or example, a CTBN rub ber a sa  fle x ib ilize r. In a d di t i on,  t he  th er m al  perf orm ance (g lass trans iti on  temperature )  o f the epox y/u rethane viny l e ster b le nds of th e p resen t inve n tion i s only sl ig h tly de c reasedc o mp ared  to unmodified ep o xy vinyl ester re sins.Th e  e p o xyvin yl ester r es ins u s ed in t h ep r e sen t  invention ma y be, for e x amp le, th eepo x y viny l est er res ins describ ed i n U.S. Pa t. No. 4,824,9 1 9 incor porate d h ere in b y  r ef ere nc e .
T h eepo x y v inyl est er ssuita blef o r thepra ctic e ofthe present i nve ntio n  ar e gen erall y pr ep arabl e by t he ad du ction of an atleas t difunct ion al  ep ox ide w i th atlea sttwo mol eculeso f a nu n s at urated monocarboxy li c ac id in wh ich th e  c ar b on-to-ca rb ondoub l e  bond  isv in yl react ive.
E x em pl ary ofsu itable  e pox y r esins arethe we ll-known  poly g licidyl ethers of polyphenyl o la l ka n es a ndthe xe2x80x 9cad v ance dxe2 x 80 x9d resin s (hi gh e rp olymers) formed byth e reac tionof polyphenol s-such asb i s phenol A , fo r  e x ample, with po lygly cidyl ethe r s, suchas th e diglyc idyl ethe r of bisph eno l A , f ore x am ple. Epoxy no v o lacs  a re also  su itable,  as  ar e c ycl oa liphaticdiepoxid es .Th egly cidyl ethers o fpol yp hen ols,s uch as  lowe r al ka ne s  (o r alken e s) s ubst it ut ed w ith  3  or 4  hyd r oxy phenylgroups, f ore xamp le ,are ofparticular in te rest for t he  pr eparat i o n of vin yl esters suitable fort he prac tic e ofthepresent i nve ntion.  Mo s t nota ble am ong s uc h e p o xides a re  th etriglycidy l eth ers o ftri( hydroxy phenyl)methanes, e t han es and propan esandt h etet r ag l yci dy l  et h e rs of tetra(hyd roxyphenyl )e t ha nes and pr o pan es .
Suita ble epo xides havingfunctiona lities hi gh er t h a n f our are ex emplifie d by theo ligom e ri c rea cti on pro du cts  of t ri(hyd r oxy pheny l)meth an es wit h epi ch lorohydr in, which may compriseas man y as7 g lycidylet her gro ups. Simi larl y, phenol/ for mal dehyd e o r  bisp heno l /f orm a ldehy de n o volacs co n ta ini n g  5  or more hy d r o xyp henyl  gr o ups ar e we ll-known as the c o rresponding po lygl y c idy l e t hers .Exemplary of s uit ab l e  acids a re  the ethyle nicallyun s atura ted mo noacid s sucha s ,f or exa mple , a crylic, m eth ac r ylic, c ro to n ic and  cin na mic ac ids. A l so s u i table are half-e sters d erive d  fr om un sa turated dica r
 better_impact resistance_than comparable vinyl ester_resins that_contain,_for example,_a_CTBN rubber as_a flexibilizer. In_addition, the thermal performance_(glass transition temperature)_of_the epoxy/urethane vinyl ester blends of the present invention is only slightly decreased compared_to_unmodified epoxy_vinyl_ester_resins.
The epoxy vinyl ester resins_used in the present invention_may be,_for example, the epoxy vinyl ester resins described_in_U.S. Pat. No._4,824,919 incorporated herein by reference.
The epoxy vinyl esters suitable_for the practice of the present_invention are generally_preparable_by_the adduction of an_at least difunctional epoxide with at_least two molecules of an unsaturated_monocarboxylic acid in which the carbon-to-carbon double_bond is vinyl reactive.
Exemplary of suitable_epoxy resins are the well-known_polyglicidyl ethers_of polyphenylol alkanes and the_xe2x80x9cadvancedxe2x80x9d resins (higher_polymers) formed_by the reaction_of polyphenols-such as bisphenol A, for_example, with polyglycidyl_ethers, such as the diglycidyl ether_of_bisphenol A, for_example._Epoxy_novolacs are_also suitable, as_are_cycloaliphatic diepoxides.
The_glycidyl_ethers of polyphenols, such as lower_alkanes_(or alkenes) substituted with 3 or 4_hydroxyphenyl groups, for example,_are_of particular interest for_the preparation of vinyl esters_suitable for the practice of the_present invention._Most notable_among such epoxides are the triglycidyl ethers of tri(hydroxyphenyl)methanes, ethanes and_propanes and the tetraglycidyl ethers of_tetra(hydroxyphenyl)ethanes and propanes.
Suitable epoxides_having functionalities_higher_than four are_exemplified_by the_oligomeric reaction products of tri(hydroxyphenyl)methanes with epichlorohydrin,_which may_comprise as many as 7 glycidylether_groups. Similarly, phenol/formaldehyde or_bisphenol/formaldehyde_novolacs containing 5 or more hydroxyphenyl_groups are well-known as the corresponding_polyglycidyl ethers.
Exemplary of suitable acids_are_the_ethylenically unsaturated monoacids such as,_for example, acrylic, methacrylic, crotonic and_cinnamic acids. Also_suitable are half-esters derived from unsaturated dicar