Document 3JenYrKOBOwx8dmLRzONxorbn

E I. DU PONT DE NEMOURS & COMPANY KREBS PIGMENTS DEPARTMENT 256 VANDERPOOL STREET NEWARK. NEW JERSEY Serial No. Copy No. 201-48-7 / L -a /JLV NEWARK PLANT PIGMENT COLOR RESEARCH REPORT Final Report 1) Stelnlite Moisture Tester - Application to Determination of Moisture and Water Soluble Salts in Iron Blue Pigmentso 2) Electrical Conductivity as a Measure of Water Soluble Poriod Covwgtlts In Iron Blue Pigments January 8, 1948 to February 17, 19480 FILE* DATE* 149 6/1/48 Njim \ N42156 DUP050066941 Copy to* #1 - Numerical File $? - Research Office (149) i - Library File (149) 4 - #10 Building File 5 - V. Chalupski - Plant Files 6 - Imperial Chemical Industries, ltd. w it 9 - W. F. Spengeman, Newark 10 - Extra Serial No. KN-48-7 Copy No. 1 NEWARK PLANT PIGMENT COLOR RESEARCH REPORT Final Report 1) Steiniite Moisture Tester - Application to Determination of Moisture and Water Soluble Salts in Iron Blue Pigments. 2) electrical Conductivity as a Measure of Water Soluble1 Salts in Iron Blue Pigments. Period Covered* January % 1948 to February 17, 1946. Charge* 1100-11-95 (AI-C-95) SUBMITTED BY* k* R. Hanke APPROVED BY* A. A. Brizzolara BATE SUBMITTED* May 19, 1948 DATE ISSUED* June 1, 1948 1 DUP050066942 4*MiM.*l* rcTioir The Steinllte Moisture tester is marketed by the Fred Stein Laboratories, Atchison, Kansas, It operates on the principle that the dielectric constant of a solid is depandint upon its moisture content, It doe# not measure dielectric constant but measures a function of the impedance changes in a capacitor where the dielectric of the capacitor is the sample in question. It was thought that such an instrument might serve as a quick method for determining moisture in iron blue pigments. When this did hot look particularly promising, the attempt was made to show some correla tion between instrument reading and water soluble salts. In connection with the water soluble salt experiment, specific elec trical conductivity of an aqueous slurry was also compared with water soluble salts determined gravimetrically. Purlin has found a Steinllte Moisture fester useful in determining the water content of "Vacuum Stock Material0, Their method, TM-209-S, can be found in our OMA book under OMA-173* CONCLPSIOKSi 1, The Steinllte Moisture Meter is unsuitable for use as a control instrument for measuring moisture or water soluble salts in Iron blue pigments. 2, Electrical resistance of a slurry can be used to good advantage for measuring water soluble salts of B-63-0 type blues. The method fails, however, when applied in the manner of of this experiment to B-216-0 type blue, presumably because the treating agent Is an uncontrolled variable* OBSERVATIONS! 1. No correlation was observed between Steinllte meter reading and moisture as measured by the Brabender oven on B-216-0, The moisture range studied was 4.6$ to 8,1$. 2, The correlation between Steinllte meter readings and moisture by Brabender oven on B-63-0 is too poor to use as a control test. The moisture range studied was from 6.8$ to 9*2$, 3, M correlation was observed between Steinlite meter readings and water soluble salts on 1-216-0 The soluble salt range studied was from 0.27$ to 0.4?$, 4, There is only poor correlation between Steinllte meter readings and water soluble salts on B-63-0, Far batter correlation is obtained with an electrical conductivity measurement on the pig ment slurry. The soluble salt range studied was from 0,9$ to 3*04$, DUP050066943 Weigh 40grama of pigment on a torsion balance and transfer to the instrument cell* Use no compression but simply make a reading according to the directions supplied with the instrument* v . .,% ' f I. Hote: The sample weight was chosen so that the sample did not quite completely fill that portion of the cell compartment between the metal plates. Under these conditions the readings were quite reproducible* If compression was used it was difficult to get the sample out of the cell*. Weigh 5 grams pigment and slurry into 70 ml of distilled water* Beat just to a boil} avoiding excessive boiling. Cool to room temperature (+28C ) in period of about one hour. Place slurry in a 25 ml graduate and measure the electrical resistance using a dip type electrode of cell constant approx* 1*0* Also make a read ing on the distilled water used for the experiment and treated in a manner similar to that of a determination. To calculate the con ductivity use the formula C a lOf C Specific conductivity in reciprocal ohms x lO? B = Instrument reading In ohms K a Cell constant which for this experiment was 0.96. Bote In the case of B-216-D, a mixture of alcohol and water was used In place of distilled water to assure complete wetting of the pigment. The mixture consisted of one part 3~A ethyl alcohol and 2 parts distilled water by volume. This followed the standard procedure for water soluble salts listed as SCR-50. The determinations were made by the Plant Analytical laboratory* The Brabender oven was used and the sample was heated to 160C for one hour. The determinations were made by the Plant Analytical laboratory* DUP050066944 3 DATA B-216-D fcflJtoa 52234 52524 52546 52548 52618 52704 Solvent TABUS I Moisture - Water Soluble Salts - Resistance ..... .... ... . Resistance Specific Reading Mtotaw). Conductivity < Mj (im5) 15300 7100 9100 6800 13600 10600 4800 6150 9400 11650 390000 6.8 14.7 11.5 15.4 7.6 9.8 21.7 17.0 11.1 8.9 0.3 Steimite Readings D-25 0-33 D-40 0-17 0-55 0-43 0-23 D-147 0-26 0-60 Percent 8,1 5.8 5.0 5.0 5*9. 4.7 5.1 4.9 6,1 4.6 Percent Water Soluble - .gfllfoi______ 0.47 0.27 0.32 0.39 0.33 TABLE II Moisture - Water Soluble Salts - Resistance - ......,-- 3sBsB 52525 84402 52413 52660 52270 SD-48476 0ist.H20 Resistence Specific Steinlite Percent Read (Cng rtlvity gg&aiRSa IfeUilME* (roro?57) 338 540 780 715 1350 580,000 308 193 % u 0.2 0-110 0.98 D-48 0-56 D-40 0-77 9.2 9.2 1:1 7.7 Percent Water Soluble .....mm........... 3.04 1.84 1.61 1.16 0.90 0.87 DUP050066945 4 mmmutjmm* the correlation charts clearly show that with B-216-D no correlation exists under the conditions of the experiment* It is probably true that if a wider range of moisture or water soluble salts had been studied, a correlation could be shown but at best it would be too poor for practical use* the Steinlite meter reading on one sample was so far removed from the other readings that it could not be plotted on the chart* Its moisture and water soluble salt content was reasonable but it was bulkier than the other samples* If test was made but it is thought that this sample contained more than the customary amount of treating agent. It is felt that variation in treating agent along with variation in moisture and water soluble salts, makes it unlikely that the Steinlite tester can find a use in the control testing of iron blue pigments, particularly if they contain a treating agent* The results on B-63-D show correlation but the correla tion is not good* It is doubtful that Stelnllte meter readings are good enough for control testing. Electrical conductivity shows up as the best for water soluble salts and may well prove to be of value in determining water soluble salts in some iron blue pigments* REFERENCE: N.B. I285-I DUP050066946 ^ t e s r r .MJHtettW*; 5 am, liee3 sceentM, c s l a A o r IN 4 t . A . DUP050066948