BIODEGRADABLE SHAPED ARTICLE CONTAINING A CORROSION INHIBITOR AND INERT FILLER PARTICLES

摘要

A shaped article comprising a biodegradable polymer ("biopolymer) filled with more than 5 wt%, and up to about 35 wt% of an inert particulate filler so as to have a WVTR in the range from at least twice to about 50 times greater than that of low density PE having a melt flow index of 1 g/10 min, each of the same thickness, is more effective to protect metal parts against corrosion than "neat" or unfilled biopolymer. Moreover a cross-section of the filled biopolymer 0.025 mm thick, is substantially transparent if the neat biopolymer is transparent. The improvement in corrosion protection is obtained without decreasing the tensile strength of the film below a critical tensile strength of 2000 psi in either the machine or transverse direction, preferably in both directions, due to the uniformity of the dispersed particles in the filled biopolymer. Such uniformity is obtained because the ingredients in the biopolymer are essentially anhydrous.