Method for producing polylactic acid block copolymer
US8211986B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Aug 10, 2007 |
| Grant date | Jul 3, 2012 |
| Priority date | — |
| Expiry date | Oct 16, 2028 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L2666/14
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
It is an object of the present invention to provide a method for producing a polylactic acid block copolymer having high molecular weight, and in lower cost, wherein only a stereo-complex crystal is capable of growing, even when heat melting process is repeated. The present invention relates to a method for producing a polylactic acid block copolymer characterized in that (i) ring-opening polymerization of D-lactide (D component) is carried out in the presence of poly-L-lactic acid (L component), or (ii) ring-opening polymerization of L-lactide (L component) is carried out in the presence of poly-D-lactic acid (D component), and mass ratio of the D component and the L component is the D component/the L component=60/40 to 91/9, or the L component/the D component=60/40 to 91/9.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.