Document G597rVVzDEk42G2nvbxamrRan

E. I. DU PONT DE NEMOURS & COMPANY KREBS PIGMENTS DEPARTMENT 256 VANDERPOOL STREET NEWARK, NEW JERSEY Copy No. / l ibr ar y c o py <v> I * * > $ *f Period Covered; NEWARK PLANT PIGMENT COLOR RESEARCH REPORT Report I-53V-D, Completion of Pleat anC -Works Dsveiopjne: April, 1943 - Fetorwy, 19/,4. FILE, DATE, 212 5-26-44 n MJO030 C5 N39982 Serial So. K8-44-33 Copy Bo. 1 Copy to* /#1 - Humerical Pile 2 - Research Office (212) 3 - library Pile (212) 4 - #10 Building Pile 5-#6 6 - Imperial Chemical Industries, ltd. jr n rn g,, n Rv 9 - Mr. C. H. Ruppreeht, Wilmington (ZCI File) 10 - SEWARK P1ART PIGMEBT COLOR RESEARCH REPORT Final Report Title* T-539-D, Completion of Plaint and Semi-Works Development Period Covered* April, 1943 - February, 1944* SUBMITTED BY* J. R. Borst APPROVED BYr V. Chalupski ft DATE SUMITTRD* 5/9/44 DATE ISSUED* 5-26-44 N39982.01 DUP050150278 2- This report completes the pleat sad semi-works development carried out m T-539-D. Pew changes have been made la the process aa previously reported sad the present summary covers only the work undertaken either to simplify rather minor points la the process or to improve the product. The previous work was reported la K8-43-79 sad 8-43-101, Mffl The first plant formula used for making Y-539-0 (K-1877) made optional either press or vat Hashing* Tat washing was attempted on two plant batches of differmat sises, each of which was made in a different vat* Practically no washing was obtained since the color failed to settle* The formula as written called for one per cent of cauatlc (on a dry pigment basis) for dispersing the sine oxide* It was assumed that the caustic was the cause for the poor settling and several batches were struck varying the amount of this Ingredient from sere to 1 per cent. Only one batch was made without caustic and this was the only one which showed an improvement in settling. This batch was of such poor q uality, however, that for some time batches were made with caustic and press washed for a considerable length of time to minimise the chloride content. Later strikes made without caustic were of satisfactory quality and settled batter than those omitting it* The reason for this Improvement in batches made without caustic soda Is not known* A few variables were Investigated in the semi-works while the plant study of settling was being carried out. It was found that a higher temperature for slurrying and striking had no offset on the tinctorial properties* Likewise, a higher volume for slurrying the sine oxide and dissolving the potassium chloride before slurrying the ZnQ were ineffective tinetorlally. The most Important semi-works result helped to clarify the effect of the caustic soda* All seraiworks batches made without caustic were equal to those with caustic and as indicated above this was contrary to plant experience. However, a batch made without caustic and with slow agitation had properties resembling those of the single poor plant batch mad# without caustic* Xt was concluded from this that the caustic functioned merely aa a substitute for agitation by dispersing the sine oxide* Two semi-works batches ware made using bichromate crystals (8-9) Instead of bichromate liquor and they analysed 0*01 and 0*02 per cent Cl and 0*02 end 0*0$ per cent flQq respectively* These batches were intended to be of high purity (low chloride and sulfate content) for testing purposes by I&f# A single laboratory laid In the work on sine yellow primer (AH-TT-P-656a) Indicated that better water resistance could he obtained if the final pH of the color was slightly lower than the usual value (approximately 6*g), Accordingly, fourteen batches finished at a slightly lower pH were tested In the primer formula- DUP050150279 -3 tions. These lots showed good consistency of P-656a properties hut the contention that a lower pH gave better water resist ance was not verified. After a few amplifications in processing, the Y-539-D process was turned over to the plant as K-1948. This formula differs from the previous standard (K-1877) as follows* 1* The caustic soda for dispersing the sine oxide has been reduced to one-eighth, for economy. 2* The strike time has been shortened, the spray for striking has been eliminated and dilution of the acid has been omitted, all for greater ease of operation. 3. The stirring time has been reduced from five to three hours to permit faster vat turn over. 4. The vat washing alternative has been eliminated since this color falls to settle well. 5* The press washing has been increased from four to six hours to insure adequate washing. At the request of the plant seme subsequent work on the washing of this code was undertaken!. With the advent of colder weather (lower water temperature) the chloride content began to run above 0.05 per cent after press washing 6 hours* Increased time of washing failed to reduce the chlorides sufficiently* A mall laboratory study indicated that washing with water at 140F removed the chlorides to below the prescribed limits. Consequently, about 4000 gallons of water (for a batch of 4300 pounds) were heated to 340F and pumped through the color* This gave very good results but caused some loss in yield due to the solubility of the sine yellow* Water heated to 90F was finally used for washing with satisfactory results. mmmm mmw DSB-44-5 DUP050150280