摘要:
A catalyst for the polymerization of olefins comprises the product obtained by contacting:(A) a titanium, zirconium or hafnium mono- or bis-cyclopentadienyl compound, this latter optionally containing a bridging group which links the two cyclopentadienyl compounds;(B) an alkyl aluminium wherein at least one alkyl is different from a straight alkyl; and(C) water.The molar ratio aluminium/water is higher than 1:1 and lower than 100:1.
摘要:
Copolymers of ethylene with comonomers selected from (a) alpha-olefins, (b) cycloolefins and/or (c) dienes, characterized by the fact that:the molar percentage of the comonomer (% .alpha.) and the density of the copolymer (D) satisfy the relation % .alpha.+150D.ltoreq.141.
摘要:
Supported catalysts for the polymerization of olefins comprise the following components: (A) a porous organic support functionalised with groups having active hydrogen atoms; (B) an organo-metallic compound of aluminium containing heteroatoms selected from oxygen, nitrogen and sulphur; and (C) a compound of a transition metal selected from those of groups IVb, Vb or VIb of the Periodic Table of the Elements, containing ligands of the cyclopentadienyl type. These supported catalysts, obtainable in the form of spherical particles, can be used in the polymerization reaction of olefins either in liquid or in gas phase, thus producing polymers endowed with a controlled morphology and with a high bulk density.
摘要:
Homo- and copolymers of ethylene endowed with very high molecular weights and narrow molecular weight distributions are obtainable by carrying out the polymerization reaction in the presence of a metallocene-based catalyst wherein the metallocene is stereorigid and it is in its meso isomeric form.
摘要:
Supported catalysts for the polymerization of olefins comprise the following components: (A) a porous organic support functionalised with groups having active hydrogen atoms; (B) an organo-metallic compound of aluminium containing heteroatoms selected from oxygen, nitrogen and sulphur; and (C) a compound of a transition metal selected from those of groups IVb, Vb or VIb of the Periodic Table of the Elements, containing ligands of the cyclopentadienyl type. These supported catalysts, obtainable in the form of spherical particles, can be used in the polymerization reaction of olefins either in liquid or in gas phase, thus producing polymers endowed with a controlled morphology and with a high bulk density.
摘要:
Homo- and copolymers of ethylene endowed with very high molecular weights and narrow molecular weight distributions are obtainable by carrying out the polymerization reaction in the presence of a metallocene-based catalyst wherein the metallocene is stereorigid and it is in its meso isomeric form.
摘要:
Supported catalysts for the polymerization of olefins comprise the following components: (A) a porous organic support functionalised with groups having active hydrogen atoms; (B) an organo-metallic compound of aluminium containing heteroatoms selected from oxygen, nitrogen and sulphur; and (C) a compound of a transition metal selected from those of groups IVb, Vb or VIb of the Periodic Table of the Elements, containing ligands of the cyclopentadienyl type. These supported catalysts, obtainable in the form of spherical particles, can be used in the polymerization reaction of olefins either in liquid or in gas phase, thus producing polymers endowed with a controlled morphology and with a high bulk density.
摘要:
A process for the preparation of amorphous copolymers of ethylene with &agr;-olefins and optionally minor amounts of polyenes are disclosed, which have the following characteristics: (A) the % by mole content of &agr;-olefin in the copolymer (%&agr;) and the ratio between the molar amount of &agr;-olefin diads and the molar content of &agr;-olefin in the copolymer (&agr;&agr;/&agr;) satisfy the following relationship: (%&agr;)−250 (&agr;&agr;/&agr;)≧10 (B) less than 2% of the CH2 groups in the polymeric chain are in sequences (CH2)n, wherein n is an even number. These copolymers are obtained by operating in the presence of particular metallocene-based catalysts having two fluorenyl groups joined together through a bridging group.
摘要:
Amorphous copolymers of ethylene with .alpha.-olefins and optionally minor amounts of polyenes are disclosed, having the following characteristics:(A) the % by mole content of .alpha.-olefin in the copolymer (%.alpha.) and the ratio between the molar amount of .alpha.-olefin diads and the molar content of .alpha.-olefin in the copolymer (.alpha..alpha./.alpha.) satisfy the following relationship:(%.alpha.)-250(.alpha..alpha./.alpha.).gtoreq.10(B) less than 2% of the CH.sub.2 groups in the polymeric chain are in sequences (CH.sub.2).sub.n, wherein n is an even number.These copolymers are obtainable by operating in the presence of particular metallocene-based catalysts having two fluorenyl groups joined together through a bridging group.
摘要:
Amorphous copolymers of ethylene with propylene, and optionally with minor amounts of polyenes, have the following characteristics: (A) the % content by mole of propylene in the copolymer (%P) and the triads ratio EPE/(EPE+PPE+PPP) satisfy the following relationship: 0.01%P+EPE/(E?E+PPE+PPP)≧1 (B) less than 2% of the CH2 groups in the chain are in sequences (CH2)n, wherein n is an even number. These copolymers are obtainable by operating in the presence of particular metallocene catalysts having two fluorenyl groups joined together through a bridging group.
摘要翻译:乙烯与丙烯和任选少量多烯的无定形共聚物具有以下特征:(A)共聚物中的丙烯含量%(%P)和三元组比EPE /(EPE + PPE + PPP) 满足以下关系:(B)链中少于2%的CH 2基团为(CH 2)n序列,其中n为偶数。这些共聚物可通过在具有两个芴基 团体通过桥接组合在一起。