| abstract |
Invention Patent: <B> "IMPROVED PROCESSING OF OLEFINE COPOLYMERS" <D>. The invention is directed to the essentially saturated hydrocarbon polymer composition comprising essentially saturated hydrocarbon polymers having A) a backbone chain; B) a plurality of essentially hydrocarbon side chains connected to A), the referred side chains each having an average molecular weight number from 2500 Daltons to 125,000 and one MWD per SEC of 1.0 - 3.5; and having A) a Newtonian limiting viscosity (<sym> ~ 0 ~) at 190 ° C at least 50% greater than that of a linear olefinic polymer of the same chemical composition and average molecular weight, preferably at least twice as much large as for the said linear polymer, B) a ratio of the modulus of the elastic plateau at 190 ° C to that of a linear polymer of the same chemical composition less than 0.5, preferably <0.3; C) a proportion of the Newtonian limiting viscosity (<sym> ~ 0 ~) to the absolute value of the complex viscosity in oscillatory shear (<sym> ^ * ^) at 100 rad / sec at 190 ° C of at least 5; and D) a proportion of the elongation viscosity measured at a stress index of 1 sec ^ -1 ^, 190 ° C, and time = 3 sec (that is, a stress of 3) to that predicted by linear viscoelasticity at the same temperature and time of 2 or higher. Preparations of ethylene and butene through anionic polymerization and hydrogenation illustrate the invention and copolymers of ethylene and hexene prepared through coordination polymerization illustrate the invention. The polymers of the invention exhibit improved processing characteristics in that the shear thinning behavior is very close to ideal polymers and exhibit improved stress thickening. |