Polycarbonate copolymer containing oxaspiroundecane group and production process therefor
US5858499A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 19, 1996 |
| Grant date | Jan 12, 1999 |
| Priority date | — |
| Expiry date | Dec 19, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/02033
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A polycarbonate copolymer which consists essentially of 5 to 95 mol % of recurring units containing a specific spiroglycol unit and 95 to 5 mol % of recurring units containing a specific biphenol unit, and has a reduced viscosity (.eta..sub.sp /c), measured at 20.degree. C. in a solution containing methylene chloride as a solvent and having a concentration of 0.5 g/dl, of at least 0.3 dl/g, a photoelasticity coefficient of 70.times.10.sup.-13 cm.sup.2 /dyne or less, and a glass transition temperature of at least 95.degree. C.; and a process for the production thereof. This polycarbonate copolymer is useful as a material for an information transmission medium or an information recording medium.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.