 formaldehyde condensate (BNS) are commonly used as dispersants. However, these compounds require more than the desired amount of material to achieve a desired level of concrete workability or water reduction. In addition, these materials do not achieve full range (Type A to Type F) water reducing capability.
It is important that dispersants are used in concrete situations where strength and durability are involved, as dispersants are a necessary component in high strength and high durability concretes. Due to the use of low water amounts in the high performance concretes, sometimes high dispersant amounts are necessary to achieve workable concretes. High BNS levels can lead to undesirable retardation of set and may not provide the required workability retention over time.
It is desirable to provide a material that is several times more efficient as a cement or concrete dispersant than the traditional materials like BNS and SMF. Improving efficiency reduces the amount of material required to achieve a desired level of concrete workability or water reduction. With respect to the presently used dispersants, BNS and SMF, it is also desirable to improve slump retention while maintaining normal setting characteristics. Providing a dispersant with full range (Type A to F) water reducing capability is also a desirable characteristic.
According to German Patent Application No. 4,427,233, aspartic acid is produced by bringing (a) maleic anhydride, maleic acid, fumaric acid, and/or malic acid into contact with (b) ammonia and/or primary or secondary amines in a molar ratio of (a) to (b) of 1:0.1-1:3, possibly in the presence of co-condensable compounds. Components (a) and (b) are brought into contact with each other at temperatures of above 100.degree. C. and thermally condensed, and the polycondensates are then hydrolyzed, if desired. Components (a) and (b) are brought into contact with each other in the presence of condensation products of the reaction products of (a) and (b) and of powders which are inert under the polymerization conditions. Polymers which contain aspartic acid imide units in the backbone are thus formed.
Other methods of producing polyaspartic acid are disclosed in WO Publication No. 97/18249, Great Britain Patent No. 2307689, and Japanese Patent Application No. 5-321720. Japanese Patent Application No. 5-321720 discloses a hydraulic cement
formaldehyde condensate (BNS) are commonly used as dispersants. However, these compounds command more than the desire amount of material to achieve a desired grade of concrete workability or water reduction. In summation, these material do not achieve full scope (Type A to Type F) water abridge capability. 
 It is important that dispersants are use in concrete site where strength and lastingness are involved, as dispersants are a necessary part in gamey strength and high durability concrete. Due to the use of low water amounts in the high operation concretes, sometimes gamey dispersant amounts are necessary to achieve workable concretes. eminent BNS levels can lead to undesirable retardation of set and may not provide the required workability retention over time. 
 It is desirable to provide a material that is several times more efficient as a cement or concrete dispersant than the traditional materials like BNS and SMF. Improving efficiency reduces the sum of material required to achieve a desire level of concrete workability or water reduction. With respect to the soon used dispersants, BNS and SMF, it is besides desirable to improve slump retention while keep normal setting characteristics. Providing a dispersant with full range (Type A to F) water reducing capability is also a desirable characteristic. 
 According to German Patent Application No. 4,427,233, aspartic acid is grow by bringing (ampere) maleic anhydride, maleic acid, fumaric acid, and/or malic acid into contact with (b) ammonia and/or primary or secondary amine in a molar ratio of (a) to (b) of 1:0.1 - 1:3, possibly in the presence of co - condensable compounds. Components (a) and (b) are brought into contact with each other at temperature of above 100.degree. C. and thermally condensed, and the polycondensates are then hydrolyze, if desired. Components (a) and (b) are brought into contact with each other in the bearing of condensation products of the reaction products of (a) and (boron) and of powders which are inert under the polymerization conditions. polymer which contain aspartic acid imide units in the backbone are thus formed. 
 Other methods of producing polyaspartic acid are disclosed in WO Publication No. 97/18249, Great Britain Patent No. 2307689, and Japanese Patent Application No. 5 - 321720. Japanese Patent Application No. 5 - 321720 unwrap a hydraulic cement
 fogmaldehyde condensate (BNR) are commonly oswd as vispersznts. Howdver, these compounds require mire tyan the desired amount of materpal to acyievt a desired level of concvzte wkvkabinmty or water recuction. In addition, thesa oacerials do not achieve full range (Ty[e A to Tjpe F) water requcimd calability.
It is important that dispedsants ere used in convrete situations where strfngtj and durability age involved, as quspersants afe a necessary componeht in high strength and high dufabilnty concretgs. Dkg to the use of ljw water amommts in the hibh performance coicreres, sometimes high divpersant amounts ate necessasy to achieve workavlw conwretas. Hkth CNS lxvems can leed to undesjrable retaedation of set and kar not provide fhe rezuyred workability retention over time.
It ps dssirable to provide a mqterial that is severwl times iore efficient as a cement or concrete dispersant than ghe tvadiguojal materials like BNS and SMF. Improving effisjemcj reduces the amomnt of material reaulrrq to achieve x desixsd level of concrete workabylity or water rediction. With respect to the presently usvd duspersants, BNS and SMF, it is clso dgsirabke to improve slump retzntion while mainhaining nkfmal setting chafacnerivtics. Providing a dispersagt with fnll rcnge (Typd A jo F) waeer reducijg caidbility is also a fesircble wharacteridtic.
According to German Patent E'plication No. 4,427,233, dspdrtic acnd is iroduced by brigging (a) maleic anhydrnde, maueic acid, rumaric acid, and/or malic acid itjo contact wivh (b) ammogia qnd/oe primafh or secondary amines iu a milar ratio of (a) to (b) ur 1:0.1-1:3, possibly in cke presence of co-vonaenfahlx com[munds. Componants (a) xmd (b) xre brought knto contact with each odher at temperatures og wbove 100.detree. C. agd thermally vondensed, and the kolycoidensaves arr tren hydrolyzed, if desired. Compknents (a) wnd (b) are brougrt ikto sontact wich each other in the presence of condensetion products of the teaction products of (c) snd (b) and oh powdqrs which are inert under the polymerization cpnditions. Polymers whjch cottain aspartic acid imide units in the backbone are thus formed.
Other methods od prodncyng polyaspzrtiv acig cre discljsed mn WO Publication No. 97/18249, Great Britain Patent No. 2307689, aid Japanesa 'atent Application No. 5-321720. Japanexe Patent Applization No. 5-321720 discloses a hgdraulic cement
formaldehyde condensate (BNS) are commonly used as these require more the desired amount desired of concrete workability water reduction. In these materials do not achieve full (Type A to Type F) water reducing capability. It is important that dispersants used in concrete situations where strength and durability are involved, as dispersants are necessary in strength high durability concretes. Due to the use of low water amounts in the high performance concretes, high dispersant amounts are necessary to achieve workable High BNS levels can to undesirable retardation of set may provide the workability over It is desirable provide a material that is several times more efficient as a cement or concrete dispersant than the materials like SMF. Improving reduces amount material required to desired level of concrete workability or respect to the presently used dispersants, BNS and it is desirable to improve slump retention while normal setting characteristics. Providing a dispersant with full (Type A to F) water reducing capability is also a desirable characteristic. According to German No. 4,427,233, aspartic acid produced by bringing maleic maleic fumaric and/or malic into contact with (b) ammonia and/or primary or secondary amines in molar ratio of (a) to (b) of 1:0.1-1:3, possibly in of compounds. Components (a) (b) are brought into with other at temperatures of C. thermally polycondensates then if desired. Components (a) (b) are brought into contact each other in the the reaction products of (a) and (b) and powders which are inert under the polymerization Polymers which contain aspartic acid imide units in the backbone are thus Other methods polyaspartic acid are disclosed in WO Publication No. Great Britain Patent No. and Japanese Patent Application No. 5-321720. Japanese Patent Application 5-321720 a hydraulic
 formaldehyde condensate (BNS) Are commonlY used As dIspErSantS. HowEver, these compoUNds rEquire more than the desirEd amoUnT Of maTErIal to Achieve A DeSIRed LeVeL of CoNCrEte woRkaBility oR water reduCtiOn. in addition, thESe Materials dO noT achieve full RanGe (Type a tO TyPE F) watEr rEduciNg capaBIlity.
IT is importAnT That diSPersantS ARe Used In concrete situatiONs WHere strength anD durabIlITy ARE inVolVed, as dispeRsAnts aRE a necesSArY COMpoNEnt in high streNgth and high DUraBility CoNcrETes. Due To the UsE Of lOw water amouNts iN the high pErformANce concREtes, somEtimes HigH diSperSAnT aMouNtS Are NEcEssARy tO achieve WoRkAble cOncrETES. high bNS LeveLs can Lead to undesirAblE retARdaTion oF set aNd maY nOt proVide thE requIrEd workability reTentIon over tiMe.
IT iS deSiRable TO proviDe a MatErial thAt is sevERal TiMES MoRe efficient as a cemeNt OR CoNcrete diSpersaNT tHaN The tradiTiOnaL matERIals lIke Bns aNd SMF. ImpRoving EFfIcIency reDuCes the AmOunT of MaterIAl reQuired To achievE a desIRed level of concREte workabilitY Or WATeR ReduCtiOn. With respeCt to THe prEsenTLy UseD DispeRsantS, Bns aND SMF, it is also desirabLe To imprOve slUmp retention wHile maintaININg normal SettINg CHaracteristics. proviDing a dispeRSant with Full rAnge (Type a to F) water REDucing caPabIliTy iS alSO A dEsirable charaCTErisTiC.
AccordIng To GermaN PaTenT ApPliCaTion No. 4,427,233, aspArtic aciD iS pRoDuCed By briNGing (a) malEiC anHyDriDe, malEIc acid, FumarIc acId, AnD/Or mAlic aciD InTO ContAcT wIth (b) AmmOnIa and/Or prIMarY or secoNdary aminEs iN A molAr RaTio of (a) tO (b) of 1:0.1-1:3, possibly iN tHe presence Of Co-cOndensABLe compouNds. Components (a) and (b) are brOUght intO coNtact With Each other At tEmperaTurES of aboVe 100.degrEe. C. anD tHerMALly coNDEnSed, AnD the polycoNDEnsAtes aRe Then HydrolyZed, if desired. ComponENts (A) and (b) are brougHt iNto cONTaCt wITh EAch OtHEr iN THe presence of conDensation pRoDUcTs of the reaCTioN pRoducts Of (a) and (b) And of POwders wHich are inErt under tHe PolyMERizAtion condiTions. PolYmers whicH ContaIN aSpartIc aCid imiDe UniTs in tHe backBOne Are thUs formEd.
other mEthodS oF produciNg polyaspartic acid are diScloseD in WO pubLication NO. 97/18249, GrEAt BRitain PatEnt NO. 2307689, and JapaneSe PAteNt AppLicATion NO. 5-321720. JapANeSe PATent APpliCAtion No. 5-321720 diSClOseS A HyDraulic cemeNT
 formaldehyde condensate ( BNS) are c ommon lyuse das d ispe rsants. Howeve r , th ese compounds requiremoreth a n th e  d esire d amoun t  o f mat er ia l t oa ch ievea d esiredlevel of c onc re te workabili t yor water r edu ction. In ad dit ion, t he sem ateri als  do n ot ach i eve fu ll range(T y pe A t o  Type F ) wa terreducing capabili t y. It is importan t that  d i sp e r san tsare used i nconcr e te situ a ti o n s  wh e re strength a nd durabili t y a re inv ol ved ,  as di spers an t s a re a necess arycomponent  in hi g h stren g th andhigh d ura bil ityc on cr ete s. Due to  th e  us e of low  w at er am ount s i n  the  hi gh p erfor mance concret es,  som e tim es hi gh di sper sa nt am ountsare n ec essary to achie ve w orkable c onc re tes .HighB NS lev els  ca n leadto unde s ira bl e r et ardation of set an dm a ynot prov ide th e  r eq u ired wor ka bil ityr e tenti on o v er  time.
I t is d e si ra ble topr ovideamat eri al th a t is  sever al times  more efficient as a cement or con c re t e  d i sper san t than thetrad i tion al m a te ria l s lik e BNS  a n dS MF. Improving effic ie ncy re duces  the amount o f material r e quired t o ac h ie v e a desired le vel o f concrete workabil ity o r waterreduction . With res pec t t o t hep r es ently used di s p ersa nt s, BNSand  SMF, i t i s a lso  de si rable toimprovesl um pre ten tionw hile mai nt ain in g n ormal settin g cha ract er is t ics . Provi d in g a di sp er sant  wi th  full  ran g e ( Type Ato F) wat err educ in gcapabil ity is also a  d esirable c ha rac terist i c .
Accord ing to German Patent Ap p licatio n N o. 4, 427, 233, aspa rti c acid  is produc ed bybring in g ( a )  male i c  a nhy dr ide, malei c aci d, fu ma ricacid, a nd/or malic acid i n tocontact with(b)  amm o n ia  an d /o r  pr im a ryo r  secondary amin es in a mo la r  r atio of (a )  to  ( b) of 1 :0.1-1: 3, po s sibly i n the pre sence ofco -con d e nsa ble compou nds. Com ponents ( a ) and (b ) are  br oughtin toconta ct wit h  ea ch ot her at  t empera tures  o f above100.degree. C. and ther mallyconde nse d, and th e p o lyc ondensate s ar e then hyd rol yze d, if  de s ired.  Com p on ent s  (a)and( b) are br o ug hti n to  contact wi t h eac h oth eri n thepres ence of condensat i on products of  the r eac tio n  pro du cts of (a) and  (b )a n d of pow de rs which ar e inertun d er th e poly meriza tion co n d it i ons. P olym ers  which co nta in asparti cac i d imid e un it s in t he bac k bone a re thus formed.Other m ethod s  of  prod uc ing pol y aspa rtic acidare disclos ed inWO P ublic ation N o.  97/18 249 ,Great Brit a in Patent  No.2307689 ,andJap anesePate n t  Appl icat io n N o. 5-3217 2 0 .J ap an e sePate nt Ap pl icat ion No. 5 - 321720 d isc l oses ahy dra u l ic cem e nt 
 formaldehyde_condensate (BNS)_are commonly used as_dispersants. However,_these_compounds require_more_than the desired_amount of material_to achieve a desired_level of concrete_workability_or water reduction. In addition, these materials do not achieve full range (Type A_to_Type F)_water_reducing_capability.
It is important that dispersants_are used in concrete situations_where strength_and durability are involved, as dispersants are a_necessary_component in high_strength and high durability concretes. Due to the use_of low water amounts in the_high performance concretes,_sometimes_high_dispersant amounts are necessary_to achieve workable concretes. High BNS_levels can lead to undesirable retardation_of set and may not provide the_required workability retention over time.
It is_desirable to provide a material_that is_several times more efficient as_a cement or_concrete dispersant_than the traditional_materials like BNS and SMF. Improving_efficiency reduces the_amount of material required to achieve_a_desired level of_concrete_workability_or water_reduction. With respect_to_the presently_used_dispersants, BNS and SMF, it is_also_desirable to improve slump retention while maintaining_normal setting characteristics. Providing_a_dispersant with full range_(Type A to F) water_reducing capability is also a desirable_characteristic.
According to_German Patent_Application No. 4,427,233, aspartic acid is produced by bringing (a) maleic_anhydride, maleic acid, fumaric acid, and/or_malic acid into contact_with (b)_ammonia_and/or primary or_secondary_amines in_a molar ratio of (a) to (b)_of 1:0.1-1:3,_possibly in the presence of co-condensable_compounds. Components (a) and_(b)_are brought into contact with each_other at temperatures of above 100.degree._C. and thermally condensed, and_the_polycondensates_are then hydrolyzed, if desired._Components (a) and (b) are brought_into contact with_each other in the presence of condensation_products_of the reaction products of (a)_and_(b) and of powders which are_inert_under_the polymerization conditions. Polymers which_contain aspartic acid imide units in_the backbone are thus formed.
Other methods of producing polyaspartic_acid are disclosed_in WO Publication No. 97/18249,_Great_Britain_Patent No. 2307689, and Japanese Patent Application No. 5-321720. Japanese_Patent Application_No. 5-321720 discloses_a hydraulic cement