Two-step process for the preparation of a (co)polycarbonate by transesterification
US5498688A · kind A · utility
82Cited by
0References
3Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jan 25, 1995 |
| Grant date | Mar 12, 1996 |
| Priority date | — |
| Expiry date | Jan 25, 2015 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01J2219/0277
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A process for the preparation of a (co)polycarbonate having an excellent hue, heat resistance, residence to hydrolysis and impact resistance by transesterification with the use of an aparatuses of a low price. In the first step, a dihydroxy compound is reacted with a carbonic diester in a reactor having a surface area contacting the dihydroxy compound and the carbonic diester, a made of a material containing iron in an amount of 20% by weight or less, to give a prepolymer and, in the second step, melt-polycondensing the prepolymer in a reactor other than the reactor used in the first step.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.