Document 93dX0bKm46gjggEyOmrwr9J3R

E. I. DU PONT DE NEMOURS & COMPANY KREBS PIGMENTS DEPARTMENT 256 VANDERPOOL STREET NEWARK, NEW JERSEY Serial No. Copy No. Numerical File r,K A pv1 v i NEWARK PLANT PIGMENT COLOR RESEARCH REPORT Progress Eepaet PLANS 8m>X OF Y-493-0 and LIES PROCESSES Period Covered: MAY 1, 1944 mmmSZ 1 X9*$ FILE: DATE: 2X4 3/?/*5 N43C8S N37977 Serial Ho. KN-45-8 Copy Ho* -* Copy to: #1 - numerical File 2 - Research Offloe (214) 3 - library File (214) 4 - #10 Building File 5-#6 " " 6n -,, Imperial Chemical Indu stries. Ltd. n g . # ft M ft 9 - Dr. D. H. Dewson/Library File. 0-e 10 - Extra. NEWARK PLANT PIGMENT COLOR RESEARCH REPORT Progress Report PLANT STUDY OF Y-493-D and 5-550-D LINE PROCESSES MAY 1, 1944 - FEBRUARY 1, 194? SUBMITTED BY* V. Chalupski APPROVED BY: Vit .. 7?utt. Chalupski 7> /fff DATE SUBMITTED: 2/23/4? DATE ISSUED: 3/7/45 DUP050150008 FUJI sway OF 1-49^-D and O-WO-D UBS PROCESSES HswBgsmm. * Plant production for a number of years of X-.493-D and the Q-550-D line of greens has shown a trend toward bluish (less olive) masstone and blue tint, This is apparently due to corrective measures which were taken to eliminate light masstone. Orientation runs in the plant over a period of a year have indicated that better control can be obtained, using a number of simple variables, the effects of which have been checked in the Development Laboratory. Shis report covers this preliminary orientation works a systematic study has been planned and is to bo carried out in the plant. Although the formulas for Y-493-D and that for the base yellow of the G-550-D line are praetieally the same, there are certain differences which are the result of differences in batch sizes and concentration. This must be borne in mind in all of the following discussion. At one time the amount of sodium bichromate used in these formulas was about 123 lbs*, per mole. A gradual drift to light masstone (by greening test) was unexplained at the time, but was corrected by the plant by decreasing the amount of chromate, and increasing the amount, of sulfate an equivalent amount. This change resulted in bluish, less olive maastones and slightly weak, bime tint. In attempting to discover the necessity for this change, information developed in the Research Laboratory on another problem indicated that the ratio between depth of masstone and blueness of tint could be varied over a wide range by changing the total acidity of the strike; it is quite likely that changes in acidity of the lead nitrate and sodium bichromate solutions which occurred over a long period were the causes for the original drift to light maastones. Following this lead, the acidity variable was studied In the laboratory and plant; results are discussed below. Another change which may have occurred in operation, the time of stirring after strike before addition of the restraining agent, was suggested by the plant for additional study. It is believed by correct combination of the three variables mentioned above chromate;sulfate ratio, total acidity and stirring time before restraining agent - can be used to give the desired control for the X-493-D and G-550-D line formulas. Most of the work done in the plant was on the G-551-D shade. In the laboratory, shading yellow only was made. DUP050150009 2 The currently standard amounts of sodium bichromate were 119 lbs. per mole for the Y-493-D and 124 lbs* per mole for the G-550-D line* Increasing this amount by 5 to 10 per cent gave slightly olive (less bluish) masstone with some lightness, and yellow tints) these results were obtained both in the plant and in the laboratory* By combining this variable with increases in soda ash in the lead nitrate , the depth of masstone was Increased with slightly less bluishness; tints remain yellow. Increases of the soda ash in the lead nitrate in the order of 10 to 25% appeared ti give these effects; larger increase up to 50JS resulted in olive and dull products* Increases in stirring time after the strike gave very definite effects in the laboratory. Increasing this stirring time resulted in dark, olive masstone and weak, dull tints. The effect was only slight with a 10 minute stir period but very noticeable in 20 minutes and even more so with a 30 minute period. In the plant, a 15 minute stirring period has been used and the effect has been rather slight in a number of cases; this should be carefully ohecked in view of the very definite effects obtained in the laboratory. See DSN-45-3 DUP050150010 Eamalaa - sasaatuta&at.jmm~ ar.51QA.XAna %=4S3A IHiMLBIBgL Batch Size 2-1/2 mol (usual) 7 mol Pb(S03>2 Temp.-vol.-pH 331# 80- 1045 gal,- 4.7 333# 75- 808 gal.- Ba2C03 40# 40# HaCl Sa2S04 Ka2Gr207.2H20 Temp,- pH 20# 13.2# 124# 80 - 4.7 15# 16.7# 119# 75 - 4.7 Tin crystals Ha2C03 - strike in 20 min, then add at once 4 W# a*TSf) 10# 10# Ha2S 3# 3# a i2c s o 4)3,i 8h 2o ( "as is" wt.) 4# 4# - adjust pH to 4,5 - 5*0 - A12(S04>3.18H20 Tin crystals Alkali - draw 3 or 4 waters 20# 4# +10# HaHC03 20# 4# 0 Na2C03 - goal yield about 326 lbs. - DUP050150011