Document pB4wknD8Zmk118aDkjbQwk4Oj

NEWARK PLANT PREPARATION OP LIGHT CHROME ORANGES "SPTJIAl REPCRT" ^S/- SZ- PIIEl CHROME ORANGES DATE! MAY- 1935 N36977 DUP050316596 fm mmmstm m vmm mms mmmn mmmm mt* {foilin' fXIBl ---------------- ms h * mr~ mm This report is baaed m work mrried out in April of IMs year following sera mnnfaoiwia difficulties on YOHUHB* It will serve to supplement the special report (ftas) of June 38* 1932* mammon, In <wnetion with name recent difficulties in the preparation of T0-27-B it was necessary to study tide process in the plant* The diffiooO.tr eium entered ms that Y0-37~B woo being obtained either strong and yellow in tint or rod in mastone. Past work on YO-27* indicated that it constated of a mixture of approximately equal moleouXar pro^rtiefts of PbOrCte and Pb0*a?b004, PldrOt of the largest particle sis# yet obtained t light in nosstono eM weak vs* Y0~2fD while Pb0*Pb8rO4 equal in masstea to IG-S?* is strong and yellow in tint* It is therefore necessary to prepare Y0-27~ by a process givia a mixture of Pb0*Pb0r4 and PbOrOe# If the operating conditions are such that we match TCH87-B in mesteni bat have aero Pb0*Pba04 in the final product we are approaching % product equal in masetene to T0-27 3> but about 40$ strong and consist ing of 100$ Pb0*Ph0r4* If altering the operating conditions results in a product containing less 5>bO*yb004 than 10-27-0 but remining equal in raaestoae. the tint will be red and weak* The mat essential factor in a Y0-27-B proses is therefore the use of quantities of materials and operating conditions wfeldi will result in the formtion of a pigment slurry containing equal molecular proportions of ?b0?bCrOt am PbSrOo, In the preparation of TO-sr?-* the lead chromate ratio should be adjusted as discussed above* The ratio of acetic add to sodium in the Socesa determines the pK and to some extent the Chrome excess* 10-270 prepared with a very slightly alkaline solution and a vory slight chrome excess* To obtain a slight alkaline reaction* there should be very slightly more than one mole of sodium per mole acetic acid* This will also result In a slight chrome excess* As the strike temperature Is increased to a boll the pigment becomes darker in masstone and slight ly red and weak in tint* If the pigment slurry is boiled after the strike* the strike temperature has little offdot* As the ratio of chro mate to lead increases, the reverse strike gives a weaker pigment than the direct strike* The strength difference is slight for products close to Y0-27-0 and is reversed at the YO~30~X> depth. The difficulty in preparing Yd-27-3 arises from the fact that large particle sire PbQ,PbQr04 is most easily prepared by increasing the alka linity and this in the YO-27-B process Increases the chromate excess and the proportion of Pb0*ybSr04# both of which act in the direction of in creasing the strength* The method now used for obtaining large particle sine Pb0*pb0ro is to boil after the strike and to use & very slight pre cipitant excess* It mam probable that any set of operating conditions resulting in large particle size Pb0*pb0roe without destroying the PbCrO* present will be satisfactory for the preparation of TO-27-B* DUPO 50316597 i4 Site ttoarwwli f Mi 490* t* f 8f ilSftt* Ml 4ft II Cftwaats f Mr 30 sioJfip&imte 6f Mi bw Ww if lMftfli ftp SW^HI feftml t*t #ii fiylttm fMi f 4A^r AHnil A19ji 9&rmI*temm. f1ldWui*I 8* *pwi. * *9lMi 8*9 Ml M Hit# SiMaMit * t*mI * pwtifel#i Ml 4ft *twill ** t# tdl Hun Mimi* M*fX*?*S* 4HHfeuy*Lipafc *9 9M9 ffttiarM i1wwly sniiiMidUtijr ifr&I iSs* tit Mtw MmH 4Hi HH&I 3$# ft# gMllftftiift* jMMtMfft #*ll ft* f,Ptg|tWt'j*tWft t niftlit W*sVf1*a*l1 ^tajrtipi* fta 41* MN i#M toil it *tft#t m 4 M in M tttiw *#"14# l*>l/2 Hews attd 3 t$V ill INI i$tefftS$i Hftlag wl Msr 4 MT9 *$&& IMtti 4*7 *ft iOOF aftaasagaam Iftiii Mi ftwttt if@H> fill iq o i *i m* OftS#** 1*1 Mi '#1 DUP050316598