Ethylene fluoro-containing copolymers
AssigneeAusimont S.p.A.
InventorsJulio A. Abusleme, Vincenzo Arcella, Giambattista Besana
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Abstract
Ethylene fluoro-containing copolymers of the ECTFE and ETFE type, optionally in the presence of a third comonomer in amount comprised between 0.1 and 10% by moles, having a viscosity between 10.sup.2 and 10.sup.5 Pa.sec with shear rates of 1 sec.sup.-1 measured at the temperature of about 30.degree. C. higher than the second melting temperature, and having a rheologic curve in the diagram shear viscosity/shear-rate with a slope higher than 200, calculated as ratio between the viscosity in Pa.sec and the shear-rate in sec.sup.-1 in the shear-rate range comprised between 1 and 10 sec.sup.-1, and having a processability zone with shear-rate values higher than 10 s.sup.-1.
Claims11
Process for the synthesis of ECTFE and ETFE fluoro-containing copolymers having a bimodal molecular weight distribution comprising polymerizing the respective comonomers until 40-95% by weight on the total of the polymer is obtained, and then adding a chain transfer agent for preparing a low molecular weight fraction of the distribution.
Dependencies are inferred from the claim text.