发明名称 Processes for preparing low molecular weight hexafluoropropylene-olefin cotelomers
摘要 Amorphous hydrofluoroolefin telomers are prepared by a free-radical polymerization process conducted at high temperature and pressure in the presence of non-monomeric chain transfer agent.
申请公布号 US8895681(B2) 申请公布日期 2014.11.25
申请号 US200611614554 申请日期 2006.12.21
申请人 E I du Pont de Nemours and Company 发明人 Howell Jon Lee;Jones Clay Woodward;Wheland Robert Clayton
分类号 C08F214/28 主分类号 C08F214/28
代理机构 代理人
主权项 1. A process comprising: 1) forming a reaction mixture by combining reactants comprising from 80 to 99 weight % of hexafluoropropylene, from 1 to 20 weight % of an olefinically unsaturated co-monomer, from 0.05 to 2 weight % of a free-radical initiator, and from 0.25 to 5 weight-% of a non-monomeric chain transfer agent, based on the total weight of the reaction mixture; 2) causing the free-radical initiator to initiate a free-radical polymerization; and 3) causing the reaction mixture to undergo free radical polymerization at a temperature in the range of 225 to 400° C. and a pressure of 40-700 MPa, for a period of 10 seconds to 1 minute, to form an amorphous hexafluoropropylene liquid telomer comprising from 30 mole % to 95 mole % of monomer units derived from hexafluoropropylene, said liquid telomer being characterized by a viscosity in the range of 1 to 10,000 centistokes at 40° C.; whereby the amorphous hexafluoropropylene liquid telomer is formed at a rate of 31-198 pounds per gallon per hour; wherein the olefinically unsaturated co-monomer is selected from the group consisting of tetrafluoroethylene, vinylidene fluoride; ethylene, perfluoroalkylvinyl ether of the structure RfOCF═CF2 wherein Rf is a C1-C4 perfluoralkyl radical; hexafluoroisobutylene; perfluoroalkylethylenes of the structure R′fCH═CH2 wherein R′f is a linear C1 to C8 perfluoroalkyl radical; vinyl fluoride (VF); trifluoroethylene, and chlorotrifluoroethylene, and the concentration of ethylene is 3 weight % or less, provided that when the olefinically unsaturated co monomer is vinylidene fluoride, perfluoropropylvinyl ether, ethylene, or tetrafluoroethylene, the total of the concentrations of vinylidene fluoride, ethylene, and tetrafluoroethylene is 10 weight % or less.
地址 Wilmington DE US