Processes for preparing copolymers
US6124409A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 12, 1992 |
| Grant date | Sep 26, 2000 |
| Priority date | — |
| Expiry date | Aug 12, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S526/921
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Disclosed is a process for preparing copolymers which comprises, in the order stated: (1) adding monomers containing unsaturated carbon-to-carbon bonds, a first polymerization initiator, a second polymerization initiator, and a solvent to a reaction vessel; (2) purging the resulting solution with an inert gas; (3) sealing the reaction vessel and pressurizing it by addition of an inert gas to a pressure of from about 20 to about 600 kilopascals over ambient atmospheric pressure; (4) maintaining the temperature within the pressurized reaction vessel at a temperature of from about 50 to about 100.degree. C. for a period of from about 60 to about 300 minutes; (5) thereafter maintaining the temperature within the pressurized reaction vessel at a temperature of from about 80 to about 115.degree. C. for a period of from about 30 to about 300 minutes, wherein the temperature in step (5) is higher than the temperature in step (4); and (6) subsequently maintaining the temperature within the pressurized reaction vessel at a temperature of from about 115 to about 160.degree. C. for a period of from about 30 to about 180 minutes, wherein the temperature in step (6) is higher than the temperatur…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.