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:
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:
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:
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。
摘要:
Catalysts for the polymerization of olefins are disclosed, which comprise the reaction product of: (A) a bridged and/or substituted cyclopentadienyl compound of titanium, zirconium or hafnium; (B) an organometallic aluminum compound of the formula (II): Al(CH.sub.2 --CR.sup.4 R.sup.5 R.sup.6).sub.w R.sup.7.sub.y H.sub.z(II) wherein in the (CH.sub.2 --CR.sup.4 R.sup.5 R.sup.6) groups, which are the same or different, R.sup.4 is an alkyl, alkenyl or arylalkyl group having from 1 to 10 carbon atoms, R.sup.5 is an alkyl, alkenyl, aryl, arylalkyl or alkylaryl group having from 3 to 50 carbon atoms which is different from a straight alkyl or alkenyl group and, optionally, R.sup.4 and R.sup.5 fused together can form a ring having from 4 to 6 carbon atoms, R.sup.6 is hydrogen or an alkyl, alkenyl or arylalkyl group having from 1 to 10 carbon atoms, the R.sup.7 substituents, same or different, are alkyl, alkenyl, aryl, arylalkyl or alkylaryl radicals containing from 1 to 10 carbon atoms and, optionally, can contain Si or Ge atoms, w is 1, 2 or 3, z is 0 or 1, y=3-w-z; and (C) water. The molar ratio aluminum/water is comprised between 1:1 and 100:1. These catalysts show an improved activity with respect to known catalysts wherein an aluminum compound different from those of the above formula is used.
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/(EPE+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:0.01%P + EPE /(EPE + PPE + PPP)> = 1(B)链中CH2基团的2%以序列(CH2)n表示,其中n为偶数。 这些共聚物可通过在具有通过桥连基团连接在一起的两个芴基的特定金属茂催化剂存在下操作而获得。
摘要:
Catalysts for the polymerization of olefins which comprise the reaction product of (a) a bridged and/or substituted cyclopentadienyl compound of titanium, zirconium, or hafnium; (b) an organometallic aluminum compound of formula Al(CH.sub.2 --CR.sup.4 R.sup.5 R.sup.6).sub.w R.sup.7.sub.y H.sub.z, wherein in the (CH.sub.2 --CR.sup.4 R.sup.5 R.sup.6) groups, which are the same or different, R.sup.4 is an alkyl, alkenyl or arylalkyl group having from 1 to 10 carbon atoms, R.sup.5 is an alkyl, alkenyl, aryl, arylalkyl or alkylaryl group having from 3 to 50 carbon atoms and, optionally, R.sup.4 and R.sup.5 can be fused together to form a ring having from 4-6 carbon atoms, R.sup.6 is hydrogen or an alkyl alkenyl or arylalkyl group having from 1 to 10 carbon atoms, the R.sup.7 substituents, the same or different, are alkyl, alkenyl, aryl, arylalkyl or alkylaryl radicals having from 1 to 10 carbon atoms and, optionally, can contain Si or Ge atoms, w is 1, 2 or 3, z is 0 or 1, and y=3-w-z; and (c) water. The molar ratio of aluminum to water is from 1:1 to 100:1. The catalysts show an improved activity with respect to known catalysts wherein an aluminum compound different from those of the invention are used.
摘要:
A process for the preparation of an ethylene/1-butene or ethylene/1-butene/diene elastomer by slurry polymerization of the monomers in a polymerization medium consisting mainly of an excess of the 1-butene maintained in liquid form, performed in the presence of a catalyst based on a metallocene compound of Ti, Zr or Hf. This process is exempt from occurrence of reactor fouling and enables the recovery of the polymer without the use of steam as a stripping agent.