Polyimide based resin composition

A carbon fiber reinforced polyimide-based resin composition comprising from 5 to 100 parts by weight of carbon fiber for 100 parts by weight of a resin composition comprising from 50 to 99 % by weight of a polyimide resin having recurring units represented by the formula (I):

• ##STR52## wherein X is a radical selected from the group consisting of a direct bond, sulfur, divalent hydrocarbon having from 1 to 10 carbon atoms, hexafluorinated isopropylidene, carbonyl, thio, sulfonyl and ether;
• Y.sub.1, Y.sub.2, Y.sub.3 and Y.sub.4 and are individually a radical selected from the group consisting of hydrogen, lower alkyl, lower alkoxy, chlorine and bromine;
• and R is a tetravalent radical selected from the group consisting of an aliphatic radical having from 4 to 9 carbon atoms, monocycloaliphatic radical having from 4 to 10 carbon atoms, monoaromatic radical, condensed polyaromatic radical and noncondensed aromatic radical connected each other with a direct bond or bridge member, and from 50 to 1% by weight of one or more thermotropic liquid crystal polymer.

A polyimide-based resin composition comprising from 5 to 200 parts by weight of potassium titanate fiber for 100 parts by weight of a resin composition comprising from 50 to 99 by weight of a polyimide resin having recurring units represented by the formula (I):

• ##STR54## wherein X is a radical selected from the group consisting of a direct hexafluorinated isopropylidene, carboxyl, thio, sulfonyl and ether;
• Y.sub.1, Y.sub.2, Y.sub.3 and Y.sub.4 are individually a radical selected from the group consisting of hydrogen, lower alkyl, lower alkoxy, chlorine and bromine;
• and R is a tetravalent radical selected from the group consisting of an aliphatic radical having from 4 to 9 carbon atoms, monocycloaliphatic radical having from 4 to 10 carbon atoms, monoaromatic radical, condensed polyaromatic radical and noncondensed aromatic radical connected each other with a direct bond or bridge member, and from 50 to 1% by weight of one or more thermotropic liquid crystal polymer.

A polyimide-based resin composition comprising from 0.01 to 25 parts by weight of a crystallization accelerator for 100 parts by weight of a resin composition comprising from 50 to 100 parts by weight of a polyimide resin having recurring units represented by the formula (I) ##STR56## wherein X is a direct bond, divalent hydrocarbon having from 1 to 10 carbon atoms, hexafluorinated isopropylidene, carbonyl, thio or sulfonyl;

• Y.sub.1, Y.sub.2, Y.sub.3 and Y.sub.4 are individually hydrogen, lower alkyl, lower alkoxy, chlorine or bromine;
• R is a tetravalent radical selected from an aliphatic 2 or more carbon atoms, alicyclic, monocyclic aromatic or fused polycyclic aromatic radical or a polycyclic aromatic radical connected to each other through a direct bond or a bridge member, and from 0 to 50 parts by weight of a thermotropic liquid crystal polymer.