Oblon, Fisher, Spivak, McClelland & Maier
Process for producing blackboard crayon
 A process for producing blackboard crayon by molding a mixture of calcium carbonate, titanium oxide and zinc oxide in place of conventional calcined gypsum or chalk, a resinous material primarily containing paraffin, beef tallow or palm oil as a coagulant, and a solvent, into a stick form. The blackboard crayon does not scatter dust. 
C
C09D
inventional
Seung J.
Lee