摘要:
Process for the polymerization of olefins CH2═CHR, in which R is hydrogen or a hydrocarbon radical with 1–12 carbon atoms, carried out in the presence of a catalyst component (A) comprising Mg, Ti and halogen as essential elements and of a catalyst component (B) capable to produce, under the same polymerization conditions, a polymer with an average particle size lower than that obtainable with the said catalyst component A. The said process provides polymers with increased bulk density.
摘要翻译:烯烃CH 2 R 2的聚合方法,其中R是氢或具有1-12个碳原子的烃基,在包含Mg,Ti的催化剂组分(A)的存在下进行 和作为必需元素的卤素和能够在相同聚合条件下生产平均粒度低于用所述催化剂组分A获得的聚合物的催化剂组分(B)。所述方法提供具有增加的堆积密度的聚合物 。
摘要:
The invention relates to a high-molecular-weight copolymer comprising ethylene and propylene units which has an ethylene content in the range from 1 to 10% by weight, a melt flow rate MFR (230/5) of
摘要:
A gaseous mixture of steam and air, a gaseous mixture of steam and nitrogen, or pure steam are passed around polyolefin granules in a deodorizing apparatus. The result is that the polyolefin granules have markedly improved properties with respect to odor and taste, and these are retained in moldings produced from the granules.
摘要:
An ethylene copolymer, a catalyst system suitable to prepare the ethylene copolymer, and a process to prepare such ethylene copolymer are described. The use of the ethylene copolymer as impact modifier in polyethylene and as compatibilizer in a polymer blend are also described. The ethylene copolymer has a density from 0.855 g/cm3 to 0.910 g/cm3, a polydispersity Mw/Mn lower than 3.5, comprises at least one first ethylene polymer component and at least one second ethylene polymer component having different comonomer contents so as to show at least two predetermined CRYSTAF peak temperatures.
摘要翻译:描述了乙烯共聚物,适于制备乙烯共聚物的催化剂体系,以及制备这种乙烯共聚物的方法。 还描述了在聚乙烯中使用乙烯共聚物作为抗冲改性剂和在聚合物共混物中作为增容剂。 乙烯共聚物的密度为0.855g / cm 3至0.910g / cm 3,多分散性Mw / Mn低于3.5,包含至少一种第一乙烯聚合物组分和至少一种具有不同共聚单体含量的第二乙烯聚合物组分,以显示 至少两个预定的CRYSTAF峰值温度。
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 active catalyst system for olefin polymerization comprises a cocatalyst, preferably an aluminoxane, and a metallocene of the formula I ##STR1## in which, preferably, M.sup.1 is Zr or Hf, R.sup.1 and R.sup.2 are alkyl or halogen, R.sup.3 is hydrogen, R.sup.4 to R.sup.6 are alkyl or aryl, --(CR.sup.8 R.sup.9).sub.m --R.sup.7 --(CR.sup.8 R.sup.9).sub.n is a single- or multi-membered chain, in which R.sup.7 can also be a (substituted) hetero atom, and m+n is zero or 1.
摘要:
A very active catalyst system for olefin polymerization comprises a cocatalyst, preferably an aluminoxane, and a metallocene of the formula I or Ia ##STR1## in which, 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 or alkyl, R.sup.5 and 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 with one or more members, in which R.sup.7 can also be a (substituted) heteroatom, and m+n is zero or 1.
摘要:
The novel metallocenes of the formula I ##STR1## in which, 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.n -- is a single- or multi-membered chain in which R.sup.7 may also be a (substituted) hetero atom, m+n is zero or 1, and R.sup.10 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 polypropylene molding composition having syndiotactic polymer chains is obtained in a high yield by the copolymerization of propylene with ethylene or a 1-olefin of the formula R.sup.a --CH.dbd.CH--R.sup.b in the presence of a catalyst comprising a metallocene of the formula I ##STR1## in which M.sup.1 is titanium, zirconium, hafnium, vanadium, riobium or tantalum, and an aluminoxane. This molding composition has a very high molecular weight, a very narrow molecular-weight distribution and very high syndiotaxy. Shaped articles produced from the molding composition are distinguished by high transparency, flexibility, bear strength and excellent surface luster.
摘要:
Olefins of the formulaR.sup.11 --CH.dbd.CH--R.sup.12(R.sup.11 and R.sup.12 =H or C.sub.1 -C.sub.14 -alkyl) are polymerized in the presence of a catalyst comprising at least one metallocene of the formula I ##STR1## (M=zirconium or hafnium) and an aluminoxane, giving polymers of high molecular weight in high yield.