 with zinc diacrylate or zinc dimethacrylate, and containing fillers and curing agents which are molded under high pressure and temperature to provide a ball of suitable hardness and resilience. For multi-piece nonwound golf balls, the cover typically contains a substantial quantity of ionomeric resins that impart toughness and cut resistance to the covers.
Ionomeric resins are generally ionic copolymers of an olefin, such as ethylene, and a metal salt of a unsaturated carboxylic acid, such as acrylic acid, methacrylic acid or maleic acid. Metal ions, such as sodium or zinc, are used to neutralize some portion of the acidic group in the copolymer, resulting in a thermoplastic elastomer exhibiting enhanced properties, such as durability, for golf ball cover construction. However, some of the advantages gained in increased durability have been offset to some degree by decreases in playability. This is because, although the ionomeric resins are very durable, they also tend to be quite hard when utilized for golf ball cover construction and thus lack the degree of softness required to impart the spin necessary to control the ball in flight. Since most ionomeric resins are harder than balata, the ionomeric resin covers do not compress as much against the face of the club upon impact, thereby producing less spin. In addition, the harder and more durable ionic resins lack the xe2x80x9cfeelxe2x80x9d characteristic associated with the softer balata related covers.
As a result, while there are currently more than fifty (50) commercial grades of ionomers available, both from DuPont and Exxon, with a wide range of properties which vary according to the type and amount of metal ions, molecular weight, composition of the base resin (i.e. relative content of ethylene and methacrylic and/or acrylic acid groups) and additive ingredients, such as reinforcement agents, etc., a great deal of research continues in order to develop golf ball cover compositions exhibiting not only the improved impact resistance and carrying distance properties produced by the xe2x80x9chardxe2x80x9d ionomeric resins, but also the playability (i.e. xe2x80x9cspinxe2x80x9d, xe2x80x9cfeelxe2x80x9d, etc.) characteristics previously associated with the xe2x80x9csoftxe2x80x9d balata covers, properties which are still desired by the more skilled golfer.
Moreover
with zinc diacrylate or zinc dimethacrylate, and containing fillers and curing agents which are cast under eminent pressure and temperature to provide a ball of desirable hardness and resilience. For multi - piece nonwound golf balls, the top typically contains a substantial measure of ionomeric resin that impart toughness and cut resistor to the covers. 
 Ionomeric resins are generally ionic copolymer of an olefin, such as ethylene, and a metal strategic arms limitation talks of a unsaturated carboxylic acid, such as acrylic fiber acid, methacrylic acid or maleic acid. alloy ions, such as sodium or zinc, are used to neutralize some part of the acidic group in the copolymer, resulting in a thermoplastic elastomer exhibiting enhanced property, such as durability, for golf musket ball cover construction. However, some of the advantages gained in increased lastingness have been offset to some degree by decreases in playability. This is because, although the ionomeric resins are very durable, they also tend to be quite hard when use for golf ball cover construction and thus lack the degree of softness required to impart the spin necessary to operate the ball in flight. Since most ionomeric resin are hard than balata, the ionomeric resin cover charge do not compress as much against the side of the golf club upon impact, thereby producing less tailspin. In addition, the harder and more durable ionic resins lack the xe2x80x9cfeelxe2x80x9d characteristic associated with the softer balata related covers. 
 As a result, while there are currently more than fifty (50) commercial grade of ionomers available, both from DuPont and Exxon, with a broad range of properties which vary harmonize to the type and amount of metal ion, molecular weight, musical composition of the base resin (i.e. relative subject of ethylene and methacrylic and/or acrylic acid groups) and linear ingredients, such as reinforcement agents, etc. , a great deal of inquiry continues in order to develop golf ball binding compositions exhibiting not entirely the improved shock resistance and carrying distance properties produced by the xe2x80x9chardxe2x80x9d ionomeric resins, but also the playability (i.e. xe2x80x9cspinxe2x80x9d, xe2x80x9cfeelxe2x80x9d, etc .) characteristics previously associated with the xe2x80x9csoftxe2x80x9d balata covers, property which are still desired by the more skilled golfer. 
 furthermore
 wihh zinc diacrylate or zikc dimethacrylatg, qnd coitaininf fillerr and curing agents which arx mooded ynder high pressure ana temperanure to peovive a ball of suivzble havbness wnd xewilience. For molti-piece notwound golf banlr, che cover typically contains a substwntial auwntity of ionoierib wesihs that impart toughness and cut rssistanbe to the covers.
Ipnomeric resins are generaply lonic copolymers ov an olefin, sucr as ethylene, and a metal salt of a unsaturated carboxylic acid, suzh as acrylic axie, mfjhacrylic acmd or ialeic acid. Metal iots, such as sodium or dinc, ere ysed to neutralize soke portion of the wcidic grmu' in the copolymer, rewuoting in d thdemoolaatmc slastoler exhibitinf enhanced properties, such as cuwqbility, for gklf bajl cover construction. However, some of the adbantages gained in incrwased durability have been offfet to some degree by decreases in playability. Thhs is ceccmfd, apthough the ionomeric resins are very durable, fhty slso tend to bc quite hard when itlloeed for golf bxll corsr construction and hhus lask thw degree jf spftness required to impart rhe spin necvssaey to control the yall in fligkt. Sinve moxt ionomeric resins are harser than bapata, the junomeric resin cuvegs dm not compress as much agaynst the hace pf the zlub upon ympact, thegeby isoducing less spin. In abditimn, the harfer and more durable ionic resiix lack the xg2x80x9wfevlxe2x80x9d ckaractcristic associaeed with the spfter bclata felated coners.
As a cesult, while there are custently more tian fifty (50) conmerxial grxaes of ionomerx available, both frim DuPont and Exxok, witf a wide range oy kriperties which vafy wcborving em the type atd aoouvy of oetal ions, nulecilar weight, composithon kf the base resin (o.e. relativg content of ethylene snd methacrylic anf/or arrylic acid grjups) and additive ingredients, auch as rfinnorcement agegts, ctc., w great decl of research continues in order to devxlop golf ball cover conpositions exhibitiug not only tie impwoved impdct resistance and cqrrying distance kroperties produced by fhe xe2f80x9chagdxe2x80x9d ionomeric resins, but also the playability (i.e. xe2x80x9cspinxe2x80x9d, xe2x80x9cdeelxe2e80x9q, etc.) charadterosticv 'reriously asslriated with the xv2x80x9csoftxe2x80x9d balata covers, propxrties whiwh are still desired by the mote skilled golfgr.
Moreover
with zinc diacrylate or zinc dimethacrylate, and and agents which molded under high a of suitable hardness resilience. For multi-piece golf balls, the cover typically contains substantial quantity of ionomeric resins that impart toughness and cut resistance to the Ionomeric resins are generally ionic copolymers of an olefin, such as ethylene, and metal of unsaturated acid, such as acrylic acid, methacrylic acid or maleic acid. Metal ions, such as sodium or are used to neutralize some portion of the group in the copolymer, in a thermoplastic elastomer exhibiting properties, as durability, golf cover However, some of advantages gained in increased durability have been offset to some degree by decreases in playability. This is although the are very they tend be quite hard for golf ball cover construction and degree of softness required to impart the spin to control ball in flight. Since most ionomeric are harder than balata, the ionomeric resin covers not compress as much against the face of the club upon impact, thereby producing less addition, the harder and durable ionic resins the characteristic with softer balata covers. As a result, while there are currently more than fifty commercial grades of ionomers available, both from DuPont and Exxon, wide of properties which according to the type amount metal ions, molecular weight, the resin of and and/or acrylic acid groups) additive ingredients, such as reinforcement etc., a great deal to develop golf ball cover compositions exhibiting not the improved impact resistance and carrying distance produced by the xe2x80x9chardxe2x80x9d ionomeric resins, but also the playability (i.e. xe2x80x9cspinxe2x80x9d, etc.) characteristics with the xe2x80x9csoftxe2x80x9d balata covers, properties which are desired by the more golfer. Moreover
 with zinc diacrylate or zinc dImethacrylAte, anD coNtaInIng fIlleRs and curing ageNTs whIch are molded under high pRessuRe ANd teMPeRaturE to provIDe A BAll Of SuItaBlE HaRdnesS anD resiliEnce. For mulTi-pIeCe nonwound goLF bAlls, the covEr tYpically contAinS a subsTaNtiAL quanTitY of ioNomeriC Resins That imparT tOUghnesS And cut rESIsTancE to the covers.
IonomERiC Resins are generAlly ioNiC CoPOLymErs Of an olefin, SuCh as eTHylene, aND a METAl sALt of a unsaturaTed carboxylIC acId, such As AcrYLic aciD, methAcRYliC acid or maleIc acId. Metal ioNs, such AS sodium OR zinc, arE used tO neUtrAlizE SoMe PorTiON of THe AciDIc gRoup in thE cOpOlymeR, resULTINg in A thErmoPlastIc elastomer exHibItinG EnhAnced PropeRtieS, sUch as DurabiLity, fOr Golf ball cover coNstrUction. HowEveR, sOme Of The adVAntageS gaIneD in incrEased duRAbiLiTY HAvE been offset to some dEgREE bY decreasEs in plAYaBiLIty. This iS bEcaUse, aLTHough The iONoMeric resIns are VErY dUrable, tHeY also tEnD to Be qUite hARd whEn utilIzed for gOlf baLL cover construcTIon and thus lacK ThE DEgREe of SofTness requirEd to IMparT the SPiN neCEssarY to coNtROl THe ball in flight. Since MoSt ionoMeric Resins are hardEr than balaTA, THe ionomeRic rESiN Covers do not comPress As much agaiNSt the facE of thE club upoN impact, thEREby produCinG leSs sPin. iN AdDition, the hardER And mOrE durablE ioNic resiNs lAck The Xe2x80X9cFeelxe2x80x9d CharacteRiStIc AsSocIated WIth the soFtEr bAlAta RelatED coverS.
As a rEsulT, wHiLE thEre are cURrENTly mOrE tHan fIftY (50) cOmmerCial GRadEs of ionOmers avaiLabLE, botH fRoM DuPont And Exxon, with a WiDe range of pRoPerTies whICH vary accOrding to the type and amounT Of metal IonS, moleCulaR weight, coMpoSition Of tHE base rEsin (i.e. RelatIvE coNTEnt of ETHyLenE aNd methacryLIC anD/or acRyLic aCid grouPs) and additive ingreDIenTs, such as reinfOrcEmenT AGeNts, ETc., A GreAt DEal OF Research continuEs in order tO dEVeLop golf balL CovEr ComposiTions exHibitINg not onLy the imprOved impacT rEsisTANce And carryinG distancE propertiES prodUCeD by thE xe2X80x9charDxE2x80x9D ionoMeric rESinS, but aLso the PlAyabilIty (i.e. Xe2X80x9cspinxE2x80x9d, xe2x80x9cfeelxe2x80x9d, etc.) chAracteRistiCs pReviously AssOCiaTed with thE xe2x80X9csoftxe2x80x9D baLatA coveRs, pROpertIes wHIcH arE Still DesiREd by the moRE sKilLED gOlfer.
MoreovER
 with zinc diacrylate or z inc dimeth acryl ate , a nd  con tain ing fillers an d  cur ing agents which are m olded  u n derh ig h pre ssure a n dt e mpe ra tu reto pr ovide  aball of  suitablehar dn ess and resi l ie nce. For m ult i-piece nonw oun d golf  b all s , the  co ver t ypical l y cont ains a su bs t antial quantit y of  ion omeric resins tha t  i m part toughness  and c ut re s i sta nce  to the co ve rs.
I o nomeric re s i n s a r e generally i onic copoly m ers  of an  o lef i n, suc h aset h yle ne, and a m etal  salt ofa unsa t uratedc arboxyl ic aci d,suc h as ac ry lic  a c id, me tha c ryl ic acidor  m aleic  aci d . M etal  io ns,suchas sodium orzin c, a r e u sed t o neu tral iz e som e port ion o fthe acidic grou p in  the copo lym er , r es ultin g  in athe rmo plastic  elasto m erex h i b it ing enhanced prope rt i e s,  such as  durab i li ty ,  for gol fbal l co v e r con stru c ti on. Howe ver, s o me  o f the a dv antage sgai ned  in i n crea sed du rability  have been offset to some degree b y  d e c re a sesinplayability . Th i s is  bec a us e,a lthou gh th ei on o meric resins are ve ry  durab le, t hey also tend  to be qui t e hard whe n ut i li z ed for golf ba ll co ver constr u ction an d thu s lack t he degree o f softne ssreq uir edt o  i mpart the spi n nece ss ary tocon trol th e b all  in  fl ig ht. Since  most io no me ri cres ins a r e harder  t han  b ala ta, t h e iono meric  res in  c o ver s do no t  c o m pres sas  muc h a ga instthef ace  of the  club upo n i m pact ,th ereby p roducing less  s pin. In ad di tio n, the h arder an d more durable ionic re s ins lac k t he xe 2x80 x9cfeelxe 2x8 0x9d c har a cteris tic as socia te d w i t h the s of ter  b alata rela t e d c overs .As a  result , while there arec urr ently more th anfift y (5 0)c om m erc ia l  gr a d es of ionomersavailable,  b o th  from DuPo n t a nd  Exxon,  with a  wide range o f propert ies which  v arya c cor ding to th e type a nd amount of me t al  ions , m olecul ar  we ight,  compo s iti on of  the b as e resi n (i. e.  relativ e content of ethylene a nd met hacry lic  and/or a cry l icacid grou ps)and additi veing redie nts ,  such  asr ei nfo r cemen t ag e nts, etc. ,  a  gr e a tdeal of res e a r chconti nue s  in or derto develop golf b a ll cover compo siti o n s e xhi b itin gnot only the i mpr ov e d  impactre sistance an d carryi ng dista nce pr operti es prod u c ed by the  xe2 x80 x9chardxe 2x8 0x 9 d ionom er ic resins , bu talso t he pla y abil i t y (i.e. xe2x80x9 cspin x e 2x80x 9 d,xe2x8 0x 9cfeelx e 2x80 x9d, etc.)  characteri sticsprev iousl y assoc ia ted wi thth e xe2x80x9 c softxe2x8 0x9dbalataco vers , p ropert iesw h ich a re s ti lldesired b y th e  m or e  sk ille d gol fe r.
M oreover
 with_zinc diacrylate_or zinc dimethacrylate, and_containing fillers_and_curing agents_which_are molded under_high pressure and_temperature to provide a_ball of suitable_hardness_and resilience. For multi-piece nonwound golf balls, the cover typically contains a substantial quantity_of_ionomeric resins_that_impart_toughness and cut resistance to_the covers.
Ionomeric resins are generally_ionic copolymers_of an olefin, such as ethylene, and a_metal_salt of a_unsaturated carboxylic acid, such as acrylic acid, methacrylic acid_or maleic acid. Metal ions, such_as sodium or_zinc,_are_used to neutralize some_portion of the acidic group in_the copolymer, resulting in a thermoplastic_elastomer exhibiting enhanced properties, such as durability,_for golf ball cover construction. However,_some of the advantages gained_in increased_durability have been offset to_some degree by_decreases in_playability. This is_because, although the ionomeric resins are_very durable, they_also tend to be quite hard_when_utilized for golf_ball_cover_construction and_thus lack the_degree_of softness_required_to impart the spin necessary to_control_the ball in flight. Since most ionomeric_resins are harder than_balata,_the ionomeric resin covers_do not compress as much_against the face of the club_upon impact,_thereby producing_less spin. In addition, the harder and more durable ionic resins_lack the xe2x80x9cfeelxe2x80x9d characteristic associated with_the softer balata related_covers.
As a_result,_while there are_currently_more than_fifty (50) commercial grades of ionomers available,_both from_DuPont and Exxon, with a wide_range of properties which_vary_according to the type and amount_of metal ions, molecular weight, composition_of the base resin (i.e._relative_content_of ethylene and methacrylic and/or_acrylic acid groups) and additive ingredients,_such as reinforcement_agents, etc., a great deal of research_continues_in order to develop golf ball_cover_compositions exhibiting not only the improved_impact_resistance_and carrying distance properties produced_by the xe2x80x9chardxe2x80x9d ionomeric resins, but_also the playability (i.e. xe2x80x9cspinxe2x80x9d, xe2x80x9cfeelxe2x80x9d, etc.) characteristics previously_associated with the_xe2x80x9csoftxe2x80x9d balata covers, properties which_are_still_desired by the more skilled golfer.
Moreover