Patent ID: 6458912
Filing Date: 2002-10-01
Classification: C08G

Abstract:
A thermoplastic polyimide having good thermal stability, comprising a repeating unit represented by the chemical formula (1), a molecular terminal being composed of the chemical formula (2) and/or chemical formula (3), characterized in that:said polyimide has a melt viscosity ratio calculated by the numerical formula (1) within a numerical range shown in the numerical formula (2) wherein the V of chemical formula 2 is a monovalent aromatic group, and T of chemical formula 3 is a divalent aromatic group; andwherein Numerical Formula 1 isMVR=MV30/MV5â€ƒâ€ƒ(1) wherein in the numerical formula (1), MV5 is a melt viscosity (Pa.sec) determined by melting a sample and maintaining at 420Â° C. for five minutes and measuring at a shear rate within a range from 30 to 500 secâˆ’1, and MV30 is a melt viscosity (Pa.sec) determined by melting a sample and maintaining at 420Â° C. for 30 minutes and measuring at a shear rate within a range from 30 to 500 secâˆ’1; andNumerical Formula 2 is1.0&lE;MVR&lE;1.5â€ƒâ€ƒ(2) wherein in the numerical formula (2), MVR is a melt viscosity ratio calculated by the numerical formula (1).