Process for manufacturing polyester
US6512078B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 25, 2001 |
| Grant date | Jan 28, 2003 |
| Priority date | — |
| Expiry date | Oct 25, 2021 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G63/80
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The present invention refers to the production of a polyester-type polymer and more particularly to the solid phase condensation of a polyester. The invention presents a process for manufacturing polyester which comprises at least the following steps: a) esterifying of transesterifying a carboxylic diacid or a carboxylic acid diester with a diol, b) prepolymerizing the esterification or transesterification product in liquid phase until an average degree of polymerization between 10 and 50, preferably between 20 and 45, c) preparing a dispersion of the prepolymer in a non-solvent of diol and non-swelling of the prepolymer liquid, the prepolymer being present in the dispersion in the form of solid particles having diameters under 2 mm and crystallized, with a crystalline lamella thickness under 17 nm, d) polymerizing in dispersed solid phase, e) recovering solid particles. The accomplishment of a dispersed solid phase polymerization permits improving the reaction kinetics. To obtain this improvement, the dispersed solid phase polymerization must be effected with a prepolymer having a particular degree of polymerization properties, of solid particle sizes and of crystalline qualities …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.