ABSTRACT
A processing additive is a material that, when added to a polymer compound at relatively low loading, will improve processability without adversely affecting physical properties.
It is difficult to determine who knowingly first used processing additives to modify a natural or synthetic polymer. "In 1865 Alexander Parks obtained a patent for the use of various materials, including fatty glycerides, oils, gum, and tars in lubricating nitro-cellulose; and John and Isaiah Hyatt obtained a patent on the use of camphor in nitro-cellulose in 1870. On May 11, 1858, H. L. Hall in Massachusetts was assigned Patent u.s. 220242 to Beverly Rubber Company for the use of asphalt, coal tar, resin and pitch to convert hard vulcanized rubber into a soft material which could be formed into useful articles."
