Process for preparing polylactic acid
US5821327A · kind A · utility
66Cited by
3References
7Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 17, 1997 |
| Grant date | Oct 13, 1998 |
| Priority date | — |
| Expiry date | Mar 17, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G63/08
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The polymerization reaction is conducted by heating a lactide, a cyclic imide compound (e.g. succinimide, etc.) and a polymerization catalyst (e.g. tin octylate, etc.) at 100-190.degree. C. with stirring under a nitrogen gas flow. It is preferred that an amount of the cyclic imide compound is from 1 to 35% by mole based on the lactide. Even if an amount of the polymerization catalyst is small, e.g. 0.00001-0.1 mole %, based on the lactide, polylactic acid can be efficiently prepared. It is possible to avoid remains of the catalyst in the polymer and coloring of the polymer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.