POLYIMIDE AND OPTICAL PART USING THE SAME

• Main Author: YAMAGISHI TOMOAKI
• Format: Patent
• Language: English
• Published: 26.03.1999
• Edition: 6
• Subjects: CHEMISTRY; COMPOSITIONS BASED THEREON; MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONSONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS; METALLURGY; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICS; ORGANIC MACROMOLECULAR COMPOUNDS; PHYSICS; THEIR PREPARATION OR CHEMICAL WORKING-UP

PROBLEM TO BE SOLVED: To obtain a polyimide that has a small optical birefringence and is useful as an optical transmission material for optical parts by using a specific diamine as a part or the whole part of the diamine component. SOLUTION: This polyimide is obtained by allowing (A) a tetra-carboxylic dianhydride to react with (B) a part or the whole of a diamine (preferably 3-100% to the mole equivalent of the whole diamines) of the formula (R1 -R4 are each H, F, CF3 , CHF2 and OCF2 where at least one is F or CF,) in a polar solvent as N-methyl-2 pyrrolidone or N,N-dimethylacetamide to form a polyimide precursor and imidizing the precursor by heating it at 80-50 deg.C for 30 minutes to 10 hours. As a diamine of the formula, 3,5-diaminobenzaotrifluoride is preferably used from the view points of the reactivity on the polyimide synthesis and of the reduction in optical birefringence of the polyimide formed.