PROCESS FOR PREPARING A CHEMICALLY BLENDED COMPOSITION OF NON-ELASTOMERIC ETHYLENE RESINS, AND SHAPED ARTICLES OF SUCH A COMPOSITION

摘要

It is known to produce a chemically blended composition of non-elastomeric ethylene resins in a multiplicity of steps in the presence of a catalyst composed of a transition metal catalyst component and an organometallic compound, by (a) forming (i) an ethylene polymer or an ethylene/alpha-olefin copolymer and (b) forming (ii) an ethylene/alpha-olefin copolymer having an alpha-olefin content of 0.2 to 30% by weight which is more than that of the polymer or copolymer (i) and an intrinsic viscosity at least 1.5 times that of the polymer or copolymer (i), said steps (a) and (b) being performed in either order with the later step being performed in the presence of the product of the earlier step. The resulting compositions do not however provide shaped articles having entirely satisfactory properties. …According to the invention compositions of improved physical properties, such as processability, impact strength etc., are prepared by a process in which ethylene is polymerized or copolymerized with the alpha-olefin in steps (a) and (b)… (1) in the presence of a catalyst composed of (A) a highly active titanium catalyst component containing titanium, magnesium and halogen and (B) an organoaluminum compound,… (2) so that the weight ratio of the polymer or copolymer (i) formed in step (a) to the copolymer (ii) formed in step (b) is (30 to less than 60) : (70 to above 40), and… (3) so that the resulting composition has an intrinsic viscosity [ eta ] of 1 to 6 and an alphaolefin content of 0.2 to 20% by weight.