Method for producing aliphatic polyester having increased molecular weight
US8852517B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 19, 2011 |
| Grant date | Oct 7, 2014 |
| Priority date | — |
| Expiry date | Apr 19, 2031 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P20/141
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The present invention addresses the problem of providing a method for continuously and effectively producing an aliphatic polyester having an increased molecular weight by preventing evaporation of a diisocyanate when blending the diisocyanate with an aliphatic polyester prepolymer in a molten state at a temperature not lower than the melting point thereof so that the diisocyanate and the aliphatic polyester prepolymer are uniformly blended.In order to solve the above-mentioned problem, the present invention provides a method for producing an aliphatic polyester having an increased molecular weight comprising the steps of (i) quantitatively injecting a diisocyanate into an aliphatic polyester prepolymer which has a number average molecular weight of 5,000 or higher and has terminal hydroxyl groups and in which at least one acid component is a succinic acid compound, in a melting state at a temperature not lower than the melting point thereof wherein the amount of the diisocyanate is equivalent to between one tenth and two times the amount of hydroxyl groups in the aliphatic polyester prepolymer, (ii) quantitatively and continuously introducing the diisocyanate-containing aliphatic …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.