Optical Properties of Polyalicyclic Polyimides.

Abstract

Fully imidized and solvent soluble polyimide films with a polyalicyclic structure were prepared from bicyclo[2.2.2]octane-2,3,5,6-tetracarboxylic 2,3:5,6-dianhydrides and aromatic diamines. The optical properties such as optical transparency and refractive indices have been evaluated. These films were entirely colorless, and the normalized transparencies in the visible region were over 86%. The films remained colorless and transparent up to 300°C when heated in air, and 400°C in N2. The polyimides had an average refractive index range of 1.599 to 1.617. The birefringencies of the BAB-based polyimides were nearly zero.

Synthese und Charakterisierung von cis- und trans-Dicyclohexyl-3,3′,4,4′- tetracarbonsäuren und ihren Dianhydriden / Syntheses and Characterization of cis- and trans-Dicyclohexyl-3,3′,4,4′- tetracarboxylic Acids and their Dianhydrides

“…A liphatische T etracarbonsäure-dianhydride sind unentbehrliche A usgangsm aterialien für lösliche und farblose, durchsichtige Polyimide [1,2]. In A usdehnung unserer U ntersuchungen zur D a rste l lung der M onom ere [3,4] haben wir versucht, Dicyclohexyl-3,3',4,4'-tetracarbonsäure und ihr D ia nhydrid zu isolieren.…”

Novel positive‐type photosensitive polyimide with low dielectric constant

“…The refractive indices of the films of Bco‐PI and Bco‐PI containing 20 wt % NT200 were determined 13, 14. The refractive indices of the sample films can be determined using polarized laser light.…”

Soluble Polyimides with Polyalicyclic Structure. Part 9. A Polyalicyclic Polyimide Bearing Spiro Structure.

“…Film refractive index and thickness were determined by a prism coupler method. [34][35][36] The in-plane (ATE) and out-ofplane (n) TMrefractive indices of the sample films can be determined using polarized laser light. An average refractive index (AV) nwas calculated using the equation nAV (2nTE + nTM)l3, and its optical anisotropy (An) is given as the difference between nTE and nTM.…”