摘要:
in which Z is selected from C, Si, O, N, S or P, with the proviso that the atoms O, S, P and N are not directly linked to either the carboxylic group or the sulfur atom of formula (I), the R2 groups, equal to or different from each other, are selected from hydrogen or a C1-C20 hydrocarbon radicals, optionally containing a heteroatom selected from halogen, P, S, N, O and Si, which can be fused together to form one or more cycles, m is a number satisfying the valences of Z and n is an integer ranging from 1 to 10, X is O or S, Y is —OR3, —NR4R5) or R6 groups in which R1 and R3 are selected from C1-C15 hydrocarbon groups, optionally containing a heteroatom selected from halogen, P, S, N, O, and Si, R4-R5 groups, independently, are hydrogen or R1 groups, and R6 groups have the same composition as R1 groups.
摘要:
The present disclosure provides a heterogeneous Ziegler-Natta catalyst system to be used in the preparation of ultra-high molecular weight polymers (UHMWP). The system includes at least one procatalyst, at least one co-catalyst, at least one hydrocarbon medium and at least one external donor, wherein the ratio of elemental magnesium to elemental titanium to halide, in the procatalyst, is 1 : 1.3: 3.7; the ratio of elemental aluminum, present in the co-catalyst to elemental titanium, present in the procatalyst, ranges between 6:1 and 12: 1; and the ratio of elemental silicon, present in the external donor to elemental titanium, present in the procatalyst, ranges between 1 : 10 and 10: 1. The present disclosure also provides a process for preparation of UHMWPE using the heterogeneous Ziegler-Natta catalyst system of the present disclosure.
摘要:
A solid titanium catalyst component for use in the production of olefin polymers or copolymers comprises titanium, magnesium, halogen and an electron donor as essential ingredients, and further comprises an inert liquid hydrocarbon in an amount of, based on the weight of said component, of 1 to 10%when said component has a uniformity coefficient of at least4, and 1 to 25%when said component has a uniformity coefficient of less than 4. The solid titanium catalyst component finds use as one component of a polymerisation catalyst also comprising an organometallic compound of a metal of Groups I to III of the Periodic Table in the production of olefin polymers and copolymers The presence of the inert liquid hydrocarbon affords polymers and copolymers of high bulk density, high stereospecifity and reduced content of fines. By controlling the amount of the liquid hydrocarbon in the titanium catalyst component reproducible results can be achieved.
摘要:
A titanium halide material has the composition TiCl y xMgCl 2 where y is 1.2to 2.9, typically 1.5 to 2.2, and x is at least 4, preferably between 6 and 10. The material may have a surface area in excess of 200 m 2 /g and a porosity in excess of 0.40 cm 3 /g. This material can be prepared by premixing titanium tetrachloride with a halocarbon compound which may contain hydrogen, for example carbon tetrachloride, reacting the mixture with an organo-magnesium compound, optionally separating and drying the solid product and thereafter treating this product with titanium tetrachloride. The transition metal composition can be used as a component of an olefin polymerisation catalyst to give a high yield of a polyolefin such as polyethylene or polypropylene.
摘要:
When activated with an aluminum alkyl and optionally an external electron donor, solid catalyst component can give high activity and stereospecificity in the polymerization of olefins.
摘要:
The present disclosure provides a heterogeneous Ziegler-Natta catalyst system to be used in the preparation of ultra-high molecular weight polymers (UHMWP). The system includes at least one procatalyst, at least one co-catalyst, at least one hydrocarbon medium and at least one external donor, wherein the ratio of elemental magnesium to elemental titanium to halide, in the procatalyst, is 1:1.3:3.7; the ratio of elemental aluminum, present in the co-catalyst to elemental titanium, present in the procatalyst, ranges between 6:1 and 12:1; and the ratio of elemental silicon, present in the external donor to elemental titanium, present in the procatalyst, ranges between 1:10 and 10:1. The present disclosure also provides a process for preparation of UHMWPE using the heterogeneous Ziegler-Natta catalyst system of the present disclosure.
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).