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 a MgCl2.mEtOH adduct in which m is from 2.5 to 3.2 optionally containing water up to a maximum of 1% wt based on the total weight of the adduct, characterized by a DSC profile in which the highest melting Temperature (Tm) peak is over 109° C. and has an associated fusion enthalpy ( H) of 103 J/g or lower. Catalyst components obtained from the adducts of the present invention are capable to give catalysts for the polymerization of olefins characterized by enhanced activity with respect to the catalysts prepared from the adducts of the prior art.
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 process for the preparation of random copolymers of propylene with c2-c10&agr;-olefins, carried out in the presence of a catalyst comprising: A) A solid component comprising a titanium compound supported on mgcl2 in active form and an electron-donor compound; b) An alkyl-al compound, and c) An electron-donor compound selected from the group of 1,3-diethers. The copolymers obtained using the said process show, for an equivalent content of &agr;-olefin, a lower content of xylene-soluble fractions when compared with the copolymers obtained with the catalysts of the prior art.
摘要:
Multistage process for the polymerization of one or more olefins of the formula CH.sub.2 .dbd.CHR, in which R is hydrogen or an alkyl, cycloalkyl or aryl group having from 1 to 10 carbon atoms, comprising:(A) a first stage of polymerization, in which a first olefin polymer is prepared in the presence of titanium catalyst or vanadium catalyst;(B) a treatment stage in which the catalyst used previously is deactivated and in which a metallocene compound is supported on the olefin polymer produced in stage (A); and(C) a second stage of polymerization in which one or more olefins are polymerized in the presence of the product obtained from stage (B).
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:
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:
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:
Polyolefin compositions comprising: (A) 20 to 50 parts by weight of a particular propylene polymer having a MWD greater than 3.5; and (B) 50 to 80 parts by weight of an elastomeric ethylene copolymer having a low enthalpy of fusion and a narrow MWD. The compositions of the invention are capable of giving, after dynamic vulcanization, thermoplastic elastomeric products having optimum elastomeric properties and a good balance of physico-mechanical properties.
摘要:
The present invention relates to polyolefin compositions comprising: (a) 20 to 50 parts by weight of a particular propylene polymer having an MWD greater than 3.5; and (b) 50 to 80 parts by weight of an elastomeric ethylene copoymerR having a low enthalpy of fusion and a narrow MWD. The compositions of the invention are capable of gining, after dynamic vulcanization, thermoplastic elastomeric products having optimum elastomeric properties and a good balance of physico-mechanical properties