摘要:
Process for the preparation of ethylene copolymers comprising the copolymerization of ethylene with olefins CH2═CHR, in which R is a hydrocarbyl radical with 1-12 carbon atoms carried out in the presence of a catalyst comprising (i) a solid catalyst component comprising Mg, Ti, halogen and specific 1,3-diethers of formula (I) in which R is a C1-C10 hydrocarbon group, R1 is methyl or ethyl, optionally containing a heteroatom, and R2 is a C4-C12 linear alkyl optionally containing a heteroatom, and (ii) an organo-Al compound. The obtained copolymers are endowed with good comonomer distribution.
摘要:
Catalyst components for the polymerization of olefins CH2═CHR, wherein R is hydrogen or a hydrocarbon radical having 1–12 carbon atoms, comprising Mg, Ti, Cl, OR groups, where R is a C1–C10 alkyl group optionally containing heteroatoms, and an ether having two or more ether groups, characterized by the fact that the Mg/Ti weight ratio is lower than 3 from 2 to 6.5 the Cl/Ti weight ratio is from 1.5 to 6, the OR/Ti weight ratio is from 0.5 to 3.5 and at least 50% of the Titanium atoms are in a valence state lower than 4. The said catalyst components allow the preparation of ethylene copolymers with a low content of xylene soluble fractions.
摘要:
A class of bridged or unbridged metallocene compounds is disclosed, wherein the cyclopentadienyl ligands have two or four adjacent substituents forming one or two alkylenic cycles of from 4 to 8 carbon atoms. These metallocenes are useful as catalyst components for the polymerization of olefins, particularly for the (co)polymerization of ethylene and for the polymerization of propylene.
摘要:
A process for the (co) polymerization of olefins of formula CH2═CHR wherein R is a hydrogen atom, a methyl or an ethyl radical, carried out in the presence of a system comprising (a) solid catalyst component comprising a compound of Ti or V not containing Metal-π bonds, Mg, halogen and optionally an electron donor compound; (b) an Al-alkyl compound; and (c) one or more non-polymerizing olefins in an amount up to 1.2% by mol with respect to the total olefins present in the reactor.
摘要:
Ethylene copolymers are prepared with comonomers selected from: (a) &agr;-olefins, (b) cycloolefins and (c) polyenes, with a content of ethylene units of between 80 and 99 mol %, a content of units derived from &agr;-olefin, cycloolefin and/or polyene comonomers of between 1 and 20 mol %, characterized in that: (a) in TREF (Temperature Rising Elution Fractionation) analysis, a quantity equal to at least 90% by weight of the copolymer is eluted within a temperature interval of less than 50° C., and (b) Mw/Mn>3, where Mw is the weight-average molecular weight and Mn is the number-average molecular weight, both determined by means of GPC.
摘要:
Ethylene based copolymers having high molecular weights, narrow molecular weight distributions, and a very good homogeneous distribution of the comonomer units can be obtained in high yields at temperatures of industrial interest, by carrying out the polymerization reaction in the presence of metallocene catalysts comprising particular bridged bis-indenyl compounds substituted in the 3-position on the indenyl groups.
摘要:
Process for preparing elastomeric copolymers of ethylene with .alpha.-olefins CH.sub.2 .dbd.CHR, optionally containing minor proportions of a diene, characterized by the use during the polymerization of a catalyst comprising the reaction product of:(I) a solid component comprising VCl.sub.3 supported on a magnesium dihalide in spherical or spheroidal shape, in active form;(II) an alkyaluminum compound;(III) optionally a halohydrocarbon.VCl.sub.3 is precipitated on said magnesium dihalide by heating VCl.sub.4 solutions in inert hydrocarbon solvents.
摘要:
A solid catalyst component for olefin polymerization, and in particular for the preparation of LLDPE, comprising Mg, Ti, halogen and an electron donor compound (ID) belonging to cyclic ethers having 3-6 carbon atoms, characterized by having the molar ratio Mg/Ti higher than 5, the molar ratio Mg/ID lower than 3, and by a specific X-ray diffraction spectrum.
摘要:
A solid catalyst component for olefin polymerization, and in particular for the preparation of LLDPE, comprising Mg, Ti, halogen and an electron donor compound (ID) belonging to cyclic ethers having 3-6 carbon atoms, characterized by having the molar ratio Mg/Ti higher than 5, the molar ratio Mg/ID lower than 3, and by a specific X-ray diffraction spectrum.
摘要:
A catalyst component comprising Ti, Mg, Al, Cl, and optionally OR1 groups in which R1 is a C1-C20 hydrocarbon group, optionally containing heteroatoms, up to an amount such as to give a molar OR1/Ti ratio lower than 0.5, characterized by the fact that substantially all the titanium atoms are in valence state of 4, that the porosity (PF), measured by the mercury method and due to pores with radius equal to or lower than 1 μm, is at least 0.3 cm3/g, and by the fact that the Cl/Ti molar ratio is lower than 29.The said catalysts are characterized by high morphological stability under the low molecular weight ethylene polymerization conditions while at the same time maintaining characteristics of high activity.