Low-fluoride, reactive polyisobutylene
US9617366B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 3, 2016 |
| Grant date | Apr 11, 2017 |
| Priority date | — |
| Expiry date | Mar 3, 2036 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F110/10
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A method of making a low-fluoride reactive PIB composition includes in one embodiment: a) providing an isobutylene-enriched C4 feedstock by way of blending a first mixed C4 feedstock with a second feedstock having a lower LB/IsoB index; (b) feeding the isobutylene-enriched C4 feedstock to a polymerization reactor with a catalyst complex comprising BF3 and a modifier selected from alcohols, ethers and mixtures thereof; (c) polymerizing the isobutylene-enriched C4 feedstock in the reactor while maintaining the reactor at a temperature above −40° C. and most preferably above −15° C. and utilizing a residence time less than 45 minutes to produce a crude PIB composition in a polymerization mixture; and (d) recovering a purified PIB composition from the polymerization mixture having a molecular weight, Mn, from 250 to 5000 Daltons and an alpha vinylidene content of at least 50 mol %. The crude PIB composition suitably has a fluoride content of less than 100 ppm and the purified PIB composition has a fluoride content of less than 20 ppm. In another aspect, ammonium salts are used to neutralize the catalyst and fluoride salts are sublimed from the product at elevated temperatures.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.