摘要:
A propylene block copolymer having good flow properties and a very good low temperature impact strength is obtained in a high yield if a catalyst which consists of a chiral metallocene, containing a bridge, of the formula I ##STR1## and an aluminoxane is used for the polymerization of propylene and the comonomers.The polymerization is carried out in two stages, a crystalline propylene polymer in liquid monomers being prepared in the first stage and a copolymer in the gas phase being prepared in the second stage.
摘要翻译:如果由式I(* CHEMICAL STRUCTURE *)(I)的手性茂金属(桥梁)组成的催化剂和(I)化合物的组成的催化剂,以高产率获得具有良好流动性和非常好的低温冲击强度的丙烯嵌段共聚物 铝氧烷用于丙烯和共聚单体的聚合。 聚合分两个阶段进行,在第一阶段制备液态单体中的结晶丙烯聚合物,在第二阶段制备气相共聚物。
摘要:
A very effective catalyst system for olefin polymerization consists of a cocatalyst, preferably an aluminoxane, and a metallocene of the formula (I) ##STR1## in which, preferably, M.sup.1 is Zr, R.sup.1 and R.sup.2 are alkyl or halogen, R.sup.3 to R.sup.6 are alkyl, --(CR.sup.8 R.sup.9).sub.m --R.sup.7 --(CR.sup.8 R.sup.9).sub.n -- is a chain having one or more members, in which R.sup.7 can also be a (substituted) hetero atom, and m+n is zero or 1. The catalyst system leads to polymers of variable molecular weight and stereotacticity, depending on the substituents R.sup.3 to R.sup.6 chosen, at polymerization temperatures which are relevant in industry.
摘要:
A very active catalyst system for olefin polymerization is composed of an aluminoxane and a metallocene of the formula I ##STR1## wherein preferably M.sup.1 is Zr or Hf, R.sup.1 and R.sup.2 are alkyl or halogen, R.sup.3 and R.sup.4 are hydrogen, R.sup.5 and R.sup.6 are alkyl or haloalkyl, --(CR.sup.8 R.sup.9).sub.m --R.sup.7 --(CR.sup.8 R.sup.9).sub.m --is a single-membered or multimembered chain in which R.sup.7 may also be a (substituted) hetero atom, and m+n is zero or 1. The catalyst system gives polymers having a high molecular weight and high stereospecificity.
摘要:
A syndiotactic polyolefin is obtained in a high yield by polymerization or copolymerization of an olefin of the formula R.sup.a --CH.dbd.CH--R.sup.b in the presence of a catalyst consisting of a metallocene of the formula I ##STR1## and an aluminoxane. This polyolefin has a very high syndiotactic index. At a low polymerization temperature, a polyolefin having a low average molecular weight and narrow molecular weight distribution is obtained, and at a high polymerization temperature a polymer having a high average molecular weight and a wide molecular weight distribution is obtained.Shaped articles produced from the polymers are distinguished by a high transparency, flexibility, tear strength and excellent surface gloss.
摘要翻译:在由式I(I)的茂金属和铝氧烷组成的催化剂的存在下,通过式R a -CH = CH-R b的烯烃的聚合或共聚,可以高产率获得间同立构聚烯烃。 该聚烯烃具有非常高的间同立构指数。 在低聚合温度下,获得具有低平均分子量和窄分子量分布的聚烯烃,并且在高聚合温度下获得具有高平均分子量和宽分子量分布的聚合物。 由聚合物制成的成型品通过高透明度,柔韧性,撕裂强度和优异的表面光泽来区分。
摘要:
Polymers of polycyclic olefins of the formulae I to IV having a viscosity number greater than 20 cm.sup.3 /g and a glass transition temperature above 100.degree. C. are obtained without ring opening at a high polymerization rate and at polymerization temperatures advantageous from the technical point of view by means of a catalyst which is composed of a stereo-rigid, chiral metallocene compound of groups IVb to VIb of the Periodic Table of the Elements and an aluminoxane. ##STR1##
摘要:
The invention relates to a process for the preparation of a predominantly crystalline ethylene/propylene copolymer having less than 15 mol % of propylene units, which can be carried out in liquid propylene as the suspending agent, if metallocene catalyst components of the formulae I, II or III are employed and the partial pressures of ethylene and propylene have a specific ratio. ##STR1## By means of this process, it is possible to increase the possible uses of polymerization plants which work with liquid propylene.
摘要:
The novel metallocenes of the formula I in which, preferably, M1 is Zr or Hf, R1 and R2 are alkyl or halogen, R3 and R4 are hydrogen, R5 and R6 are alkyl or haloalkyl, —(CR8R9)m—R7—(CR8R9)n— is a single- or multi-membered chain in which R7 may also be a (substituted) hetero atom, m+n is zero or 1, and R10 is hydrogen, form, together with aluminoxanes as cocatalysts, a very effective catalyst system for the preparation of polyolefins of high stereospecificity and high melting point.
摘要:
A very effective catalyst system for the polymerization or copolymerization of olefins comprises a cocatalyst, preferably an aluminoxane or a supported aluminoxane, and a metallocene of the formula I in which, in the preferred form, M1 is Zr or Hf, R1 and R2 are halogen or alkyl, R3 is alkyl, R4 to R12 are alkyl or hydrogen and R13 is a (substituted) alkylene or heteroatom bridge. The metallocenes, in particular the zirconocenes, produce polymers of very high molecular weight, in the case of prochiral monomers polymers of very high molecular weight, very high stereotacticity and very high melting point, at high catalyst activities in the industrially interesting temperature range between 50 and 80° C.
摘要:
A highly effective catalyst system for the polymerization of olefins comprises a cocatalyst, preferably an aluminoxane, and a metallocene of the formula I ##STR1## where M.sup.1 =Zr or Hf, R.sup.1 and R.sup.2 =(C.sub.1 -C.sub.3)-alkyl or chlorine, R.sup.3, with the proviso that at least one of the radicals R.sup.3 is not hydrogen, is hydrogen, F, Cl, --OR.sup.7, --NR.sup.7 R.sup.8, --P(O)R.sup.7 R.sup.8, --P(OR.sup.7).sub.2 or SR.sup.7, R.sup.4 is a ##STR2## radical, and m plus n are zero or 1.
摘要:
In the case of Ziegler catalysts based on a metallocene as the transition metal component and an aluminoxane as the activator, preactivation of the metallocene with the aluminoxane results in a considerable increase in the activity of the catalyst system. Furthermore, 1-olefin polymers of a high degree of isotacticity and having compact, spherical particles, a very narrow particle size distribution and a high bulk density are obtained by means of a catalyst system of this type.