Document G672EX52VMao7EM6X2xk03qRx

E. I. DU PONT DE NEMOURS & COMPANY KREBS PIGMENTS DEPARTMENT 256 VANDERPOOL STREET NEWARK. NEW JERSEY Serial No. KN-49-23 Copy No. 1 NEWARK PLANT PICMENT COLOR RESEARCH REPORT Y-489-D - CORRECTION OF MASSTONE DARKNESS AND DULLNESS Period Covered: 2/18/48 to 3A5/49 FILE: DATE: 4/26/49 N42207 Kjfcayt ----- ------ --_ copy ni #1 * Huserlcal PH* a - Research Office (211.1) $ - Libra-y File (211.1) 4 - ao Building PO 5 - V# Chalupeid. * Plant Files 6 * D. B. Kmiaa 7 .Retere Srlal Ho. KH-49*23 Cor Bo# l REMARK HUHf pxoim c o l o r r es ear c h r zpo s t Final Rape** Title* Y-4S9-D * CORRECTION OF KASSTCBS fififflCtsxpG MD DOUUMS Period Covered* 2/XS/4S to 3A5/49 Charges 1101-11-3 1101-12-3 sumaTEiD Bis AWTSP ^r< DATS 31MTTED* 4A5/49 DATE ISSHSDt 4/26/49 DUP050067264 Bwmm fh development of Y-499-D began in 1939 at a customer** request for a light yellow having high gloss, After laboratoiy and seoi-wrks study, a process was set op Whisk Involved the use of a large amount of elm and a calcium rosinate addition to achieve high gloss, Simplification studies yielded a more Intense produet. During 1946 and 194? the quality OS straight performance was about 15# with nattt of th# gubstandami n&topiAi btifit dftric and Ml la tfiofam# mmu i Burly in 1948 the Chemical Division assumed supervision to correct this serious quality difficulty. , .am ^ A strong lead excess is necessary during the heat development of in order to produce material equal or hotter than standard In aneeteme color. 1 process embodying this discovery has bsan establishod as standard for ' plant manufacture of X-4S94>, ^> Product* which darken less than current X-489-D production cm drying in varnish drier submits can ho prepared by replacing the sodium orthojfcOophattea with sodium pyrophosphate or by omitting the silicate. a In early efforts to correct the dark, dull maeetone of material mail on standard formula, the conventional variables mere tried, namely, increasing the salt and raising the development temperature. A mixture of sodium chromate abet sodium sulfate was tried following the heat development* instead of the sulfate slone. Alum mas also triad at this point. Hons of these variables proved consistently sudeessful altho occasional ''OK" batches were obtained. During this time there mas some evidence of deterioration in the grinding step* altho all the difficulty eould not be attributed to this cause alone. During December of 1946 a number of batches were made exactly as the original standard and were supervised in detail. Proa this study it was definitely concluded that standard material eould not Consistently be mads on standard formula. It was also concluded that there was no significant difference between material mad* in the green unit (Vat 260) or in the yellow unit (Vat 245). Attfchfs point a seai-worka study was initiated during which a nuaber of variables wars trisdi longer strike time, shorter strike time* high tempenatuasi drying, method of soda ash addition, increased concentrations, emission of sulfate after the heat development and quick processing. Do definite Iliads were obtained. - Because of the extreme urgency of ths problem, work was also underway in . the plant Haw Katerial Laboratory. During this study, it ms discovered that a light, intense aasetone product eould be made by increasing the formulated amount of lend nitrate by Ibis variable was immediately tried on a semi-works and plant scale. The plant production was intense versus standard, but 7% weak, red ami dull in tint, and low in finish. This material was found to b* too week even for shading purposes. Prom tim* to time the soesotsd ahluments of 1*469.0 which wme darker and duller than standard but decided to accept nothing but standard quality after January 1949. Intensive laboratory work was started in order to determine the fundamental cause of the trouble, lbs offset of using extra load nitrate was first DUP050067265 Investigated, based on tbs earlier Raw Material Laboratory work* It was found that an inorease of only 2$ In load nitrate consistently gave light, intense massteoe products. While aaterial on standard fonuls varied considerably mi w i, Shewed that in tbs standard formula the amount of precipitants, including soda ash, after mte#Ik* tftft snanoh to GTiQitkiiitt fill the load. ^Phe only lad 4m antntiflfi <lii>lne the heat devalocmant wan do# to the solubility of lead chloride* A SB& increase in lead, however, insured a strong lead excess daring the development, this fact was bora# cat in actual laboratory strikes, the range of lead excecoes between standard anna M m investigated **> it was concluded that as lens as a strong lead excess is - maintained, the color will be satisfactory, Largs increases only weaken the final pnednet without farther improvement In the aasetone. A 2$ increase was selected as a safe figure, ihe lead excesses wers estimated by spotting slurry filtrate on a spot paper with sodium sulfide. It was also shown that a batch deficient in lead (but not with a throne excess) oould be saved by an extra lead addition before heat developing. Semi-Works strikes yielded light. Intense products on the 2$ lead excess formula and plant trial was suds. Fear batches were equal or better than standard in B&ssteab but were somewhat red In tint. Reducing the salt in the strike yielded a green tint shading batch which was weed in a blend of ahippable quality, the Production Qdvisicn rescued supervieion of plant manufacture. Altrho iqaterf^l equal to standard was by production made on the 2$ lead excess formula, it wee observed that the lots became dark versus standard on drying in the varnish drier rubout. Investigation showed that material mads on standard formula also darkened. Laboratory strikes showed that thereplace- meat of the orthophosphate with a somewhat waller amount of pyrophosphate greatly improved the darkening tendency as did the emission of the silicate. She customer was also aware of this deficiency. Inasmuch as he felt that it tod little practical significance for hie application, no plant work along this line wax attempted. DSH-4$kL8 Seedl-works study. DSK-49-19 Plant study. Sffi*1332 Laboratory work. Sgggg. the following references summarise nearly all the work done on since its original development and may be referred to for the background of thi present formula* KS-39^254 Laboratory and saal-vorks study* KK-4&-65 History and process description, ISK-40-163 Plant work to improve standard. mA&*232 AttiBffiU Id ifitjrov* colter and ft?i^#gs m-0*260 Plant development. KN-42-278 Progress report on T-489-D sad Y-529-D. KK-43124 Plant development. KN-43-136 Use of Zinc Rssinate. airff li-t and otwrfl < f<,option study. DUP050067266