Sulfonation process
US5117041A · kind A · utility
2Cited by
3References
10Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Nov 13, 1990 |
| Grant date | May 26, 1992 |
| Priority date | — |
| Expiry date | Nov 13, 2010 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G63/918
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Allyl end-capped propylene terephthalate polyester oligomers are sulfonated in an aqueous system in the presence of a free radical initiator by a process in which only a part (about 15% to 40%) of the source of bisulfite is added at the start of the sulfonation step with the remainder being added later in that step, in such increments as will permit maintaining a clear single phase, to give sulfinate-containing sulfonated products, following which the sulfinate content is oxidized to give sulfonated end-capped propylene terephthalate polyester oligomers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.