Patent ID: 7038095

Claim:
A method for producing a mixture of fluoroalkyl iodide telomers by telomerization, each of which telomers is represented by the formula (I): R f (CF 2 CF 2 ) n I (I) wherein R f represents a fluoroalkyl group whose number of carbon atoms is in the range of 1 to 10 and n is an integer representing a polymerization degree, with the polymerization degree n equal to or more than k that is an integer of 3 or more, which comprises the steps of: (1) obtaining a first reaction mixture containing a mixture of fluoroalkyl iodide telomers represented by the formula (I) with the polymerization degree n of 1 or more by reacting tetrafluoroethylene with a fluoroalkyl iodide represented by the formula: R f I wherein R f represents a fluoroalkyl group whose number of carbon atoms is in the range of 1 to 10 in a first reactor; (2) separating the first reaction mixture into: a first fraction including a fluoroalkyl iodide telomer of the formula (I) with the polymerization degree n equal to or less than (k−2) or a mixture thereof, and the fluoroalkyl iodide represented by the formula: R f I; a second fraction including a fluoroalkyl iodide telomer represented by the formula (I) with the polymerization degree n of (k−1); and a third fraction including a mixture of fluoroalkyl iodide telomers each of which is represented by the formula (I) with the polymerization degree n equal to or more than k; and (3) obtaining a second reaction mixture including a mixture of fluoroalkyl iodide telomers each of which is represented by the formula (I) with the polymerization degree n equal to or more than k, by reacting the second fraction with tetrafluoroethylene in a second reactor.