Document RJp3D7j6BKYYwnKRmBbD3bqZv

CHROME COLORS PROGRESS REPORT #1 IHTROEUCTXON; During an examination of nine year old testa panels on the atmospheric exposures fences a panel coated with zinc chromate on silica vas found to he in extremely good condition comparing favorable with M50. Our zinc chromate on silica has two unique properties, it is black or dark gray in color and non lead. It would be ex tremely useful in places where either of these properties is desir able. Under U. S. Patent 3,072,495 we have patent protection until 1990. Because of this renewed interest two large laboratory quantities were prepared for further laboratory and field testing. SUMMARY AMD COKCLUSIQNS: A quantity of 40 lbs. was prepared. This is a duplication of the 1956 "3MZ" material, which showed sudh good properties. Far identification it was marked - Pigment 3M lot 9667. While this material was adequately coated (70$ of the larger particles) a second 25 lb. quantity vas prepared containing 0.25$ lithium chromate to improve the coating. This sample was marked - Figment llffi lot 6568. Both samples were submitted to the Paint Department. N 27322 ML 000041450