초록

Particulate polyimide molding resin characterized by high surface area and low crystallinity and molded articles prepared therefrom having unusually high toughness.

대표청구항 ▼

In a solid particulate polyimide, the polyimide having the recurring unit [Figure] wherein R is a tetravalent radical containing at least one 6-carbon atom ring characterized by benzenoid unsaturation and wherein the four carbonyl groups are attached directly to different carbon atoms in the radical

In a solid particulate polyimide, the polyimide having the recurring unit [Figure] wherein R is a tetravalent radical containing at least one 6-carbon atom ring characterized by benzenoid unsaturation and wherein the four carbonyl groups are attached directly to different carbon atoms in the radical and wherein each pair of carbonyl groups is attached to adjacent carbon atoms in a 6-membered benzenoid ring of the radical and wherein R′is a divalent radical containing at least one six-carbon atom ring, each ring characterized by benzenoid unsaturation, and, when at least two rings are present in R′, no more than one of the valence bonds is located on any one of the rings, the particles having a surface area of greater than 20 square meters per gram, the improvement wherein the polyimide repeating unit contains less than two flexible linkages and is substantially amorphous. A molded article of the polyimide of claim 1 having a density of at least about 1.30 g/cc and containing less than about 2% filler and which exhibits a tensile elongation of greater than about 20% and a tensile strength of greater than about 12 kpsi. A molded article of claim 2 wherein the filler is graphite.