摘要:
Catalyst components for the preparation of ethylene (co)polymers capable to produce polymers with high bulk density, to avoid the problems of formation of fines and that have a high activity are provided. Said catalyst components are characterized by comprising a non-stereospecific solid catalyst component, comprising a titanium compound and a magnesium dihalide, which is pre-polymerized with an alpha olefin CH2═CHR1 wherein R is a C1–C8 alkyl group, to such an extent that the amount of the α-olefin pre-polymer is up to 100 g per g of said solid catalyst component.
摘要:
The present invention relates to an adduct comprising MgCl2, an alcohol (ROH) in which R is a C1-C10 hydrocarbon group, and a compound containing a transition metal M selected from the Groups 3 to 11 or the lanthanide or actinide groups of the Periodic Table of the Elements (new IUPAC version) in an amount such as to give a weight of M atoms lower than 10% based on the total weight of the adduct. The catalyst components that are obtained by reacting the adducts with halogenating agents show very high specific activity.
摘要:
The present invention relates to catalysts component for the polymerization of ethylene and its mixtures with olefins CH2═CHR, wherein R is an alkyl, cycloalkyl or aryl radical having 1-12 carbon atoms, comprising Ti, Mg, halogen, and electron donor belonging to 1,2-diethers as internal electron donor compound. The catalyst of the invention is suitably used in (co)polymerization processes of ethylene to prepare (co)polymers having narrow Molecular Weight Distribution (MWD) and high bulk density.
摘要:
The present invention relates to catalysts component for the polymerization of ethylene and its mixtures with olefins CH2═CHR, wherein R is an alkyl, cycloalkyl or aryl radical having 1-12 carbon atoms, comprising Ti, Mg, halogen, and electron donor belonging to 1,2-diethers as internal electron donor compound. The catalyst of the invention is suitably used in (co)polymerization processes of ethylene to prepare (co)polymers having narrow Molecular Weight Distribution (MWD) and high bulk density.
摘要:
Solid adducts comprising MgCl2 and water and optionally an organic hydroxy compound (A) selected from hydrocarbon structures containing at least one hydroxy group, said compounds being present in molar ratio defined by the following formula MgCl2.(H20)n(A)p in which n is from 0.6 to 6, p ranges from 0 to 3, said adduct having a porosity (PF), measured by the mercury method and due to pores with radius equal to or lower than 1 μm, of at least 0.15 cm3/g with the proviso that when p is 0, (PF) is equal to or higher than 0.3 cm3/g.
摘要:
A catalyst component for olefin (co)polymerization, and in particular for the preparation of LLDPE, comprising Mg, Ti, halogen and an electron donor compound (ED) belonging to ethers, esters, amines, ketones, or nitriles, characterized in that the molar ratio Mg/Ti is higher than 5, and the molar ratio ED/Ti is higher than 3.5. The said catalyst components display a homogeneous distribution of the comonomer in and among the copolymer chains.
摘要:
Catalyst component comprising Mg, Ti, Hf, a halogen and, optionally, —OR groups where R is a C1-C20 hydrocarbon group, characterized in that (a) the Mg atoms are present in an amount higher than 7% based on the total weight of the said catalyst component, (b) the amount of Mg, Ti, and Hf atoms is such that the Mg/Ti molar ratio ranges from 3 to 25 and the Hf/Ti molar ratio is lower than 1.5 and (c) when —OR groups are present their amount is such that the —OR/Ti molar ratio is lower than 2.
摘要:
The present invention relates to a slurry process for preparing an ethylene polymer having a melt flow ratio F/P, according to ASTM 1238, of higher than 25, carried out in two or more stages of polymerization at temperatures in the range from 60 to 120° C., in which at least two of the said two or more polymerization stages are carried out under different concentration of a molecular weight regulator, said process being carried out in the presence of a catalyst system comprising the product obtained by contacting (A) a solid catalyst component comprising Ti, Mg, halogen, and having a porosity (PF), measured by the mercury method and due to pores with radius equal to, or lower than, 1 μm of at least 0.3 cm3/g and a surface area determined by BET method, of lower than 100 m2/g, and (B) of an organoaluminum compound.
摘要:
Solid Lewis adducts comprising MgCl2, a Lewis base (LB) belonging to ethers, esters, ketones, silanes or amines and an alcohol ROH, in which R is a C1-C15 hydrocarbon group optionally substituted with heteroatoms containing groups, which compounds are in molar ratios to each other defined by the following formula MgCl2(ROH)m(LB)n in which m ranges from 0.05 to 6, n ranges from 0.08 to 6. The solid Lewis adducts herein can be used to prepare catalysts having good morphological stability, and high polymerization activity.
摘要:
A catalyst component for the polymerization of olefins comprising a titanium compound, a Mg-dihalide, a difunctional electron donor compound (ED) selected from diesters, diketones, diamines or diethers, and a monofunctional electron donor compound (MD) selected from ethers, esters, amines or ketones, wherein a molar ratio ED/MD is higher than 10.