Process for preparation of cis-1,4 poly(isoprene)
US4146693A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 2, 1977 |
| Grant date | Mar 27, 1979 |
| Priority date | — |
| Expiry date | Dec 2, 1997 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F136/08
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Improved continuous process for synthesis of cis-1,4 poly(isoprene). In the commercial process for synthesis of cis-1,4 poly(isoprene) only a portion of the monomer charged is polymerized. The polymer, thus obtained, is separated from the unreacted monomer which in turn is recycled with solvent back into the system for conversion to additional polymer. Fresh monomer must be added from a separate feed to this recycle stream in sufficient quantity to replace or "make-up" for that which was converted to polymer. In the improved process of this invention, this "make-up" isoprene monomer is dried and then is introduced into the process subsequent to the initiation of polymerization of the isoprene monomer already present within the system, but prior to deactivation of the polymerization catalyst. Dehydration of "make-up" isoprene prior to its introduction into the process stream at the above juncture avoids deactivation of the still active catalyst with water. The still active catalyst is thus free to react with other impurities, thereby either removing them from the "make-up" isoprene, or substantially reducing their concentration. This improved process permits the use of a "make-up" i…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.