Process for producing polycarbonate resin
US6252036A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 13, 1999 |
| Grant date | Jun 26, 2001 |
| Priority date | — |
| Expiry date | Oct 13, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G64/307
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The purpose of this invention is to produce a stabilized terminal-blocked polycarbonate resin with a limited number of the terminal hydroxy groups having excellent thermal stability, color stability and hydrolysis resistance by an industrially advantageous method using a terminal blocking agent. In the production of a polycarbonate by the melt-polycondensation of an aromatic dihydroxy compound with an aromatic carbonic acid diester in the presence of a polycondensation catalyst, a terminal blocking agent expressed by the following formula (1) ##STR1## [in the formula, R.sup.1 is chlorine atom, methoxycarbonyl group or ethoxycarbonyl group; R.sup.2 is an alkyl group having a carbon number of 1 to 30, an alkoxy group having a carbon number of 1 to 30, an aryl group having a carbon number of 6 to 30 or an aryloxy group having a carbon number of 6-30] is added after the melt-polycondensation to the system in an amount of 0.3 to 4 mol-equivalent based on the hydroxy terminal group amount of the polycarbonate at 200 to 350.degree. C. under a pressure of 1,013 hPa (760 mmHg) or below for 0.1 second or longer and, thereafter, a stabilizer is added and kneaded into the system at 200 to 350.…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.