Copolyesters and methods of their production
US5977291A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 22, 1997 |
| Grant date | Nov 2, 1999 |
| Priority date | — |
| Expiry date | Sep 22, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC12P7/625
- WIPO fieldBiotechnology
- WIPO sectorChemistry
Abstract
A hydroxycarboxylic acid copolyester of R-stereospecific configuration contains a majority of first repeating units capable of forming a highly crystalline high-melting homopolyester and a minority of second repeating units capable when randomly copolycondensed with said first repeating units of lowering the melting point of said homopolyester and is characterised by one or more of: higher crystalline melting point, shorter crystallising time, higher notched impact strength at age 1 month, as compared with corresponding random polyester, and said majority repeating units in the polyester chain being present in blocks longer than correspond to their over-all molar proportionality. The copolyester may be made by fermentation, controlling the distribution of repeating units by reference to the pattern of feeding substrates corresponding to the respective repeating units.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.