Abstract: Ethylene copolymers with octene and/or ethylene terpolymers with alpha-olefins from 3 to 12 carbon atoms, optionally in the presence of other comonomers containing more than one unsaturation, usable as additives to increase the gas oil properties at low temperatures, obtainable by polymerization of the monomers in the presence of catalysts comprising: a bis-cyclopentadienyl derivative having the general formula:

Abstract: Ethylene copolymers with octene and/or ethylene terpolymers with alpha-olefins from 3 to 12 carbon atoms, optionally in the presence of other comonomers containing more than one unsaturation, usable as additives to increase the gas oil properties at low temperatures, obtainable by polymerization of the monomers in the presence of catalysts comprising: a bis-cyclopentadienyl derivative having the general formula: (Cp1Cp2)—M—(L2L3) containing groups with oxygen bound to the transition metal, wherein M is a metal from the IIIb group to the Vb group or of the lanthanide series of the Element Periodic Table; Cp1 and Cp2, equal to or different from each other, represent cyclopentadienyls bound to M with delocalized &pgr; bonds.

Abstract: Ethylene copolymers with alpha-olefins utilizable as additives to increase the properties of middle distillates at low temperatures, obtainable by polymerization in the presence of catalysts comprising the reaction product between:

Abstract: Ethylene copolymers with alpha-olefins utilizable as additives to increase the properties of middle distillates at low temperatures, obtainable by polymerization in the presence of catalysts comprising the reaction product between: 1) a bis-cyclopentadienyl derivative having the general formula: (Cp1Cp2)—M—(L2L3) containing groups with oxygen bound to the transition metal, wherein M is a metal from the IIIb group to the IIb group or of the lanthanides series of the periodic table of the elements; 2) a co-catalyst chosen from alumoxanes or boranes.

Abstract: Polymerization process to obtain elastomeric copolymers or terpolymers based on ethylene for cold flow improver (CFI) having a viscosimetric average molecular weight ranging between 600 and 16,000.a) The process includes polymerizing monomers in suspension in the presence of an alpha-olefin liquid under reaction conditions, in the presence of an amount of solvent from about 5 to 30% by volume of the reactor volume in the presence of a polymerization catalyst able to give the X.sub.2 and/or X.sub.4 parameters, lower less than or equal to 0.02, X.sub.2 and X.sub.4 representing the fraction of uninterrupted methylenic sequences of 2 and 4 methylenic groups between two successive methyl or methylene groups respectively in the polymeric chain, as compared with the uninterrupted total sequences of methylene groups determined by .sup.

Abstract: The filter plugging point and the pour-point at low temperatures of compositions based on liquid hydrocarbons from refining are improved by means of the addition, preferably in solution, of a mixture of an ethylene copolymer with another copolymerizable monomer and of an imidized acrylic polymer.

Abstract: The fluidity at low temperatures of compositions based on refinery liquid hydrocarbons can be improved by adding, preferably under solution, [l.sub.4 ]-methacyclophanes with substituents, obtained from the condensation reaction of a resorcin with a product containing an aldehyde group, followed by a reaction with halides of organic acids or alkyl halides.

Abstract: The fluidity at low temperatures of compositions based on liquid hydrocarbons from refining is improved by the addition, preferably in solution, of ethylene/propylene/(conjugated diene) copolymers or terpolymers, containing 20-55% of propylene, optionally degraded by thermo-oxidation, and structurally characterized by values of at least one of X.sub.2 and X.sub.4 parameters, which are equal to, or lower than, about 0.02, indicative of the absence in the polymeric chain of propylene linking inversions.