A process for the preparation of a solid catalyst component for the polymerization of CH.sub.2CHR olefins, wherein R is hydrogen or hydrocarbyl radical with 1-12 carbon atoms, made from or containing a Ti compound on a Mg chloride based support, including the steps of (a) reacting a Mg based compound with a liquid medium made from or containing a Ti compound, at a temperature ranging from 0 to 150 C., thereby yielding solid particles; and (b) suspending the solid particles coming from step (a) in a liquid medium made from or containing hydrocarbons at a temperature ranging from 10 to 100 C., wherein step (a) or (b) is carried out in the presence of 0.2 to 20.0% by weight, with respect to the amount of Mg compound, of particles of a solid compound containing more than 50% by weight of SiO.sub.2 units and having average particle size from 1 to 100 m.

A solid catalyst component for use in olefinic polymerization, includes titanium, magnesium, a halogen, and an internal electron donor compound; wherein: the internal electron donor compound is at least one compound represented by Formula (I)):

##STR00001##

A solid catalyst component for use in olefinic polymerization, includes titanium, magnesium, a halogen, and an internal electron donor compound; wherein: the internal electron donor compound is at least one compound represented by Formula (I)):

##STR00001##

A propylene 1-hexene copolymer containing from about 5.5 to about 9.0% by weight, based upon the total weight of the copolymer, of 1-hexene derived units having: a) two melting temperature peaks in the DSC plot having a difference in height ranging from 0 to 5 mW; b) the higher melting temperature, measured by DSC, ranging from about 141.0 C. to about 151.0 C.; and c) Melt Flow Rate (MFR, measured according to ASTM D 1238, 230 C./2.16 kg) from about 3.5 to about 8.0 g/10 min.

A propylene 1-hexene copolymer containing from about 5.5 to about 9.0% by weight, based upon the total weight of the copolymer, of 1-hexene derived units having: a) two melting temperature peaks in the DSC plot having a difference in height ranging from 0 to 5 mW; b) the higher melting temperature, measured by DSC, ranging from about 141.0 C. to about 151.0 C.; and c) Melt Flow Rate (MFR, measured according to ASTM D 1238, 230 C./2.16 kg) from about 3.5 to about 8.0 g/10 min.

A solid catalyst component for use in olefinic polymerization, includes titanium, magnesium, a halogen, and an internal electron donor compound; wherein: the internal electron donor compound is at least one compound represented by Formula (I)). ##STR00001##

A solid catalyst component for use in olefinic polymerization, includes titanium, magnesium, a halogen, and an internal electron donor compound; wherein: the internal electron donor compound is at least one compound represented by Formula (I)). ##STR00001##

A solid catalyst component for the polymerization of olefins made from or containing Mg, Ti and an electron donor of formula (I) ##STR00001##
wherein R.sup.1 and R.sup.7 groups, equal to or different from each other, are selected from C.sub.1-C.sub.15 hydrocarbon groups, R.sup.2 group is selected from C.sub.1-C.sub.10 hydrocarbon groups, and R.sup.3 to R.sup.6 groups, independently, are selected from hydrogen or C.sub.1-C.sub.15 hydrocarbon groups which can be fused together to form one or more cycles. The catalyst system based on the solid catalyst component is endowed with high activity and stereospecificity.

A solid catalyst component for the polymerization of olefins made from or containing Mg, Ti and an electron donor of formula (I) ##STR00001##
wherein R.sup.1 and R.sup.7 groups, equal to or different from each other, are selected from C.sub.1-C.sub.15 hydrocarbon groups, R.sup.2 group is selected from C.sub.1-C.sub.10 hydrocarbon groups, and R.sup.3 to R.sup.6 groups, independently, are selected from hydrogen or C.sub.1-C.sub.15 hydrocarbon groups which can be fused together to form one or more cycles. The catalyst system based on the solid catalyst component is endowed with high activity and stereospecificity.

Disclosed are a polypropylene-based resin composition comprising 5 to 47 parts by mass of a propylene-based polymer (A) having an MFR of 50 to 150 g/10 min and an amount of a decane-soluble part of 6% by mass or more, 0 to 30 parts by mass of a propylene homopolymer (B) having an MFR of 10 to 500 g/10 min, 23 to 30 parts by mass of an ethylene--olefin copolymer (C) which is a random copolymer composed of ethylene and an -olefin having 4 to 8 carbon atoms, and has a density of 0.850 to 0.890 g/cm.sup.3 and an MFR of 0.5 to 30 g/10 min, and 30 to 40 parts by mass of an inorganic filler (D) having an average particle size of over 3.0 m and less than 5.0 m [the total amount of the components (A) to (D) is 100 parts by mass]; and an automobile exterior member obtained by injection-molding or press-molding the composition.