The present disclosure relates to a catalyst component for the polymerization of olefins comprising Mg. Ti and an electron donor such as mercaptoester derivatives of the general formula (I).

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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 R.sup.2 groups, equal to or different from each other, are selected from hydrogen or a C.sub.1-C.sub.20 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 OR.sup.3, NR.sup.4R.sup.5) or R.sup.6 groups in which R.sup.1 and R.sup.3 are selected from C.sub.1-C.sub.15 hydrocarbon groups, optionally containing a heteroatom selected from halogen, P, S, N, O, and Si, R.sup.4-R.sup.5 groups, independently, are hydrogen or R.sup.1 groups, and R.sup.6 groups have the same composition as R.sup.1 groups.

The present invention relates to a solid Ziegler-Natta catalyst component for use in olefin polymerization. The catalyst component comprises magnesium, titanium, halide, one or more dicylopentyldialkoxysilane compounds, one or more dialkylaminotrialkoxysilane compounds, and one or more internal electron donors comprising urea, phthalate and 1,3-diether. The catalyst components, according to present invention, are able to produce polypropylene polymers having high isotacticity with high melt flow rate.

A metallocene complex of formula (I): each X is a sigma-ligand; in the group R.sub.2Si at least one R is methyl or ethyl, and the other R is selected from methyl, ethyl, n-propyl, isopropyl, n-butyl or isobutyl, pentyl, hexyl, cyclohexyl and phenyl; each R.sup.1 independently is the same or can be different and are a CH.sub.2R.sup.7 group, with R.sup.7 being H or linear or branched C.sub.1-6-alkyl group, C.sub.3-8 cycloalkyl group, or C.sub.6-10 aryl group; each R.sup.2 is independently a CH, CY, CH.sub.2, CHY or CY.sub.2 group, wherein Y is a C.sub.1-6 hydrocarbyl group and where n is 2-6; each R.sup.3 and R.sup.4 are independently the same or can be different and are hydrogen, a linear or branched C.sub.1-6-alkyl group, a C.sub.7-20 arylalkyl, C.sub.7-20 alkylaryl group, C.sub.6-20 aryl group, or an OY group, wherein Y is a is a C.sub.1-6 hydrocarbyl group; R.sup.5 is a linear or branched C.sub.1-6-alkyl group, C.sub.7-20 arylalkyl, C.sub.7-20 alkylaryl group or C.sub.6-20-aryl group; and R.sup.6 is a C(R.sup.8).sub.3 group, with R.sup.8 being a linear or branched C.sub.1-6 alkyl group; (A) wherein at least one R.sup.3 per phenyl group and at least one R.sup.4 is not hydrogen, and wherein at least one R.sup.3 per phenyl group and at least one R.sup.4 is hydrogen; or (B) wherein one R.sup.3 is an OY group, wherein Y is a is a C.sub.1-6 hydrocarbyl group, in 4 position of each phenyl group and the two other R.sup.3 groups are tert-butyl groups; and/or (C) wherein one R.sup.4 is an OY group, wherein Y is a is a C.sub.1-6 hydrocarbyl group, in 4-position of the phenyl ring and the two other R.sup.4 groups are tert-butyl groups. ##STR00001##

A heterophasic polypropylene copolymer having an MFR2 of 0.05 to 20 g/10 min (ISO 1133 at 230 C. with a loading of 2.16 kg) and a melting point (Tm) of 156 to 164 C. (measured by DSC according to ISO 11357) wherein the heterophasic polypropylene copolymer comprises at least the following components: (A) 55.0 to 95.0 wt % of a crystalline fraction (CF) having a comonomer content of 0 to 3.0 wt %; and (B) 5.0 to 45.0 wt % of a soluble fraction (SF) having a comonomer content of 12 to 45 wt %; wherein the intrinsic viscosity (IV) (in decalin at 135 C.) of the soluble fraction (SF) is 2.5 to 11 dl/g, and wherein the amount of crystalline fraction (CF) and the amount of soluble fraction (SF) are determined in 1,2,4-trichlorobenzene at 40 C.

Processes of polymerizing olefins include contacting ethylene, a (C.sub.3-C.sub.40)alpha-olefin comonomer, and a solvent in the presence of a chain transfer agent and a catalyst system, the catalyst system comprising a metal-ligand complex according to formula (I). ##STR00001##