Method for the production polyester with improved melting properties and crystallization properties
US9133303B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 19, 2006 |
| Grant date | Sep 15, 2015 |
| Priority date | — |
| Expiry date | Jun 12, 2026 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G63/80
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The method for the production of a polyester with improved melting properties and crystallization properties comprises the steps of (a) production of a pre-polyester melt with an average molecular weight (Mn) of 2000 to 16000 g/mol, (b) solidifying and shaping the melt into pre-polyester particles, and (c) thermally treating the pre-polyester particles in a solid phase in the presence of a transesterification catalyst whereby a molecular weight increase (ΔMn) of more than 2000 g/mol occurs. In addition, the prepolyester particles have a carboxyl end group content (XCOOH) of between 0.25 and 0.6 before step c and during the thermal treatment step c, the proportion of the esterification reaction (E) to the polycondensation reaction (E+T) is between 0.5 and 1.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.