FIELD OF THE INVENTION

[0001] The present disclosure relates to Ziegler-Natta heterogeneous catalyst components for the polymerization of olefins, in particular propylene, comprising a Mg dihalide, a Ti compound having at least one Ti-halogen bond and at least an electron donor compounds selected from 1,3 -di ethers. The catalysts components are particularly suited for the preparation of propylene homo and copolymers.

BACKGROUND OF THE INVENTION

[0002] Catalyst components for the stereospecific polymerization of olefins have been disclosed in the art. Concerning the polymerization of propylene, Ziegler-Natta catalysts are used which, in general terms, comprise a solid catalyst component, constituted by a magnesium dihalide on which are supported a titanium compound and an internal electron donor compound, used in combination with an Al-alkyl compound. Conventionally however, when a higher crystallinity of the polymer is desired, also an external donor (for example an alkoxysilane) is needed in order to obtain higher isotacticity. Esters of phthalic acid, particularly diisobutylphthalate, are used as internal donors in catalyst preparations. The phthalates are used as internal donors in combination with alkylalkoxysilanes as external donor. This catalyst system gives good performances in terms of activity, isotacticity and xylene insolubility.

[0003] In some instances, it is desirable to make polymers using catalyst systems that do not use phthalates as an electron donor.

[0004] The patent applications EP361494A2, W002/100904 and W02021/063930 describe solid catalyst components for the polymerization of olefins comprising, as an internal electron-donor compound, a 1,3 -di ether characterized by a specific structure. Notwithstanding the generally good performances, it is still felt the need of a catalyst component, free from phthalate donors, showing at the same time a very high polymerization activity and a very high stereospecificity.

[0005] The applicant has surprisingly found that a specific group of 1,3-diethers used as internal donors provide to the catalyst component a very high activity and a very high stereospecificity even in the absence of an external donor. SUMMARY OF THE INVENTION

[0006] Accordingly, one of the objects of the present patent application is a solid catalyst component for the polymerization of olefins comprising a magnesium halide, a titanium compound having at least a Ti-halogen bond and at least an electron donor of formula (I) in which R ¹ and R ² are, independently, C1-C5 alkyl groups, X is Si or C, R ³ and R ⁴ groups, independently, are selected from hydrogen, C1-C20 hydrocarbon groups and halogens with the proviso that at least two R ³ are not hydrogen.

DETAILED DESCRIPTION OF THE INVENTION

[0007] Preferably, R ¹ and R ² are the same and are selected from C1-C4 linear or branched alkyl groups and more preferably from methyl groups.

[0008] The term hydrocarbon groups includes distinct groups such as alkyl, cycloalkyl, arylalkyl, alkenyl, aryl, arlkylaryl and also hydrocarbon groups fused together to form saturated or unsaturated cycles.

[0009] Preferably, R ⁴ groups, independently, are selected from hydrogen, C1-C10 hydrocarbon groups and halogens. More preferably they selected from hydrogen, C1-C4 linear or branched alkyl groups and halogens. Still more preferably, only one or two of R ⁴ groups are C1-C4 linear or branched alkyl groups or halogen. Preferred alkyl groups are methyl, isopropyl or t-butyl, while preferred halogens are Cl and F. The structures in which all R ⁴ groups are hydrogen are also preferred.

[0010] R ³ groups are preferably selected from hydrogen and C1-C10 hydrocarbon groups and halogens. When R ³ is a hydrocarbon group it is preferably selected from C1-C4 linear or branched alkyl groups, groups linked together to form a C6 saturated ring optionally substituted with C1-C4 linear alkyl groups; Especially preferred alkyl groups are methyl, ethyl and isobutyl. [0011] When R ³ is a halogen it is preferably selected from Cl and F. More preferably it is F.

[0012] According to a preferred embodiment, X is carbon and R ³ is a hydrogen, a C1-C20 hydrocarbon group or halogen, Preferably, the hydrocarbon group is selected from C1-C4 linear or branched alkyl groups more preferably from methyl. Most preferred are the structures in which one R ³ is selected from hydrogen and the remaining two from methyl groups.

[0013] Another group of preferred structures are those in which X is carbon and R ³ is hydrogen or a halogen group preferably selected from Cl and F more preferably from F. Most preferred are the structures in which at least two of R ³ are selected from F and more preferably those in which all the R ³ groups are F.

[0014] According to another preferred embodiment, X is Si and R ³ is a hydrogen or hydrocarbon group preferably selected from C1-C4 linear or branched alkyl groups more preferably from methyl or ethyl. Most preferred are the structures in which all R ³ groups are selected from methyl.

[0015] Specific examples of compounds of formula (I) that can be advantageously used include: 2-cyclohexyl-2-isopentyl-l,3-dimethoxypropane, 2-cyclohexyl-2-(3,3-difluorobutyl)- 1 , 3 -dimethoxypropane, 2-cy cl ohexyl-2-(3 ,3 -dibromobutyl)- 1 ,3 -dimethoxypropane, 2- cy cl ohexyl-2-(3,3-di chlorobutyl)- 1,3-dimethoxypropane, 2-cyclohexyl-2-(3,3,3- trifhioropropyl)- 1,3 -dimethoxypropane, 2-cyclohexyl-2-(3,3,3-tribromopropyl)-l,3- dimethoxypropane, 2-cyclohexyl-2-(3,3,3-trichloropropyl)-l,3-dimethoxypropane, 2- cyclohexyl-2-(3,3-difluoropropyl)-l,3-dimethoxypropane, 2-cyclohexyl-2-(3,3- dibromopropyl)- 1,3 -dimethoxypropane, 2-cyclohexyl-2-(3,3-dichloropropyl)-l,3- dimethoxypropane, 2-cyclohexyl-2-(3,3-dichloro-3-fluoro-propyl)-l,3-dimethoxyp ropane, 2- cy cl ohexyl-2-(3,3-di chi oro-3 -bromo-propyl)- 1,3-dimethoxypropane, 2-cyclohexyl-2-(3,3- difluoro-3 -bromo-propyl)- 1 , 3 -dimethoxypropane, 2-cy clohexyl-2-(3 , 3 -difluoro-3 -chloro- propyl)- 1,3-dimethoxypropane, 2-cy cl ohexyl-2-(3, 3 -difluoro-5-methylhexyl)- 1,3- dimethoxypropane, 2-cy cl ohexyl-2-(3,3-di chi oro-5-methylhexyl)- 1,3-dimethoxypropane, 2- cyclohexyl-2-(3-chloro-3-isobutyl-5-methylhexyl)-l,3-dimetho xypropane, 2-cyclohexyl-2-(3- bromo-3-isobutyl-5-methylhexyl)-l,3-dimethoxypropane, 2-cyclohexyl-2-(3-fluoro-3- isobutyl-5-methylhexyl)-l,3-dimethoxypropane, 2-cyclohexyl-2-(3-fluoro-3-isopentyl-6- methylheptyl)- 1,3 -dimethoxypropane, 2-cyclohexyl-2-(3-chloro-3-isopentyl-6-methylheptyl)- 1,3-dimethoxypropane, 2-cy cl ohexyl-2-(3-bromo-3-isopentyl-6-methylheptyl)- 1,3- dimethoxypropane, 2-cyclohexyl-2-(3,3-diphenylbutyl)-l,3-dimethoxypropane, 2-cyclohexyl- 2-(3, 3 -diphenylpropyl)- 1,3 -dimethoxypropane, 2-cyclohexyl-2-(3,3,3-triphenylpropyl)-l,3- dimethoxypropane, 2-cyclohexyl-2-(3,3,3-tris(4-chlorophenyl)propyl)-l,3-dimeth oxypropane, 2-cyclohexyl-2-(3,3-dimethylbutyl)-l,3-dimethoxypropane, 2-cyclohexyl-2-(3-methylpentyl)-

1,3 -dimethoxypropane, 2-cy cl ohexyl-2-(3 -ethylpentyl)- 1,3 -dimethoxypropane, 2-cyclohexyl- 2-(3,3-diethylpentyl)-l,3-dimethoxypropane, 2-cyclohexyl-2-(3-isopropyl-4-methylpentyl)-

1.3-dimethoxypropane, 2-cyclohexyl-2-(3,3-diisopropyl-4-methylpentyl)-l,3- dimethoxypropane, 2-cy cl ohexyl-2-(cyclohexylethyl)- 1,3 -dimethoxypropane, 2-cyclohexyl-2- (cyclopentylethyl)- 1 ,3 -dimethoxypropane, 2-cyclohexyl-2-(phenethyl)- 1,3- dimethoxypropane, 2-cy cl ohexyl-2-(2 -trimethylsilylethyl)- 1,3 -dimethoxypropane, 2- cyclohexyl-2-(2-triisopropylsilylethyl)-l,3-dimethoxypropane , 2-cyclohexyl-2-(2- triphenylsilylethyl)-l,3-dimethoxypropane, 2-cy cl ohexyl-2-(2 -methyldiphenylsilylethyl)- 1,3- dimethoxypropane, 2-cyclohexyl-2-(2-dimethylphenylsilylethyl)-l,3-dimethoxypro pane, 2- cyclohexyl-2-(2-(tris(4-chlorophenyl)silyl)ethyl)-l,3-dimeth oxypropane, 2-cyclohexyl-2-(2- (bis(4-chlorophenyl)(methyl)silyl)ethyl)-l,3-dimethoxypropan e, 2-cyclohexyl-2-isopentyl-

1.3 -diallyloxypropane, 2-cy clohexyl-2-(3, 3 -difluorobutyl)- 1,3 -di ethoxypropane, 2- cy cl ohexyl-2-(3, 3 -dibromobutyl)- 1,3 -diallyloxypropane, 2-cyclohexyl-2-(3,3-dichlorobutyl)- 1 , 3 -diethoxypropane, 2-cy clohexyl-2-(3 , 3 ,3 -trifluoropropyl)- 1 , 3 -diethoxypropane, 2- cy cl ohexyl-2-(3, 3, 3 -tribromopropyl)- 1,3 -di ethoxypropane, 2-cyclohexyl-2-(3,3,3- tri chloropropyl)- 1,3 -dipropoxypropane, 2-cyclohexyl-2-(3,3-difluoropropyl)-l,3- diallyloxypropane, 2-cyclohexyl-2-(3,3-dibromopropyl)-l,3-diethoxypropane, 2-cyclohexyl- 2-(3, 3 -di chloropropyl)- 1,3 -dipropoxypropane, 2-cyclohexyl-2-(3,3-dichloro-3-fluoro-propyl)-

1.3 -di ethoxypropane, 2-cyclohexyl-2-(3,3-dichloro-3-bromo-propyl)-l,3-dipropoxypr opane,

2-cy clohexyl-2-(3 , 3 -difluoro-3 -bromo-propyl)- 1 , 3 -dibutoxypropane, 2-cy clohexyl-2-(3 , 3 - difluoro-3 -chloro-propyl)- 1 ,3 -dipropoxypropane, 2-cyclohexyl-2-(3 ,3 -difluoro-5- methylhexyl)- 1,3 -di ethoxypropane, 2-cy clohexyl-2-(3,3-di chi oro-5-methylhexyl)- 1,3- dipropoxypropane, 2-cyclohexyl-2-(3-chloro-3-isobutyl-5-methylhexyl)-l,3- diisopentoxypropane, 2-cyclohexyl-2-(3-bromo-3-isobutyl-5-methylhexyl)-l,3- diethoxypropane, 2-cyclohexyl-2-(3-fluoro-3-isobutyl-5-methylhexyl)-l,3-dipro poxypropane, 2-cyclohexyl-2-(3-fluoro-3-isopentyl-6-methylheptyl)-l,3-die thoxypropane, 2-cyclohexyl-2- (3 -chi oro-3 -i sopentyl-6-methylheptyl)- 1 , 3 -dibutoxypropane, 2-cy clohexyl-2-(3 -bromo-3 - isopentyl-6-methylheptyl)-l,3-dipropoxypropane, 2-cyclohexyl-2-(3,3-diphenylbutyl)-l,3- diallyloxypropane, 2-cyclohexyl-2-(3,3-diphenylpropyl)-l,3-diallyloxypropane, 2-cyclohexyl- 2-(3,3,3-triphenylpropyl)-l,3-diethoxypropane, 2-cyclohexyl-2-(3,3,3-tris(4- chlorophenyl)propyl)-l,3-diallyloxypropane, 2-cyclohexyl-2-(3,3-dimethylbutyl)-l,3- di ethoxypropane, 2-cy cl ohexyl-2-(3 -methylpentyl)- 1,3 -diallyloxypropane, 2-cyclohexyl-2-(3- ethylpentyl)-l,3-diisopentoxypropane, 2-cyclohexyl-2-(3,3-diethylpentyl)-l,3- diethoxypropane, 2-cyclohexyl-2-(3-isopropyl-4-methylpentyl)-l,3-diethoxyprop ane, 2- cyclohexyl-2-(3,3-diisopropyl-4-methylpentyl)-l,3-diethoxypr opane, 2-cyclohexyl-2- (cyclohexylethyl)- 1,3 -di ethoxypropane, 2-cyclohexyl-2-(cyclopentylethyl)-l,3- diallyloxypropane, 2-cyclohexyl-2-(phenethyl)-l,3-diisopentoxypropane, 2-cyclohexyl-2-(2- trimethylsilylethyl)-l,3-dibutoxypropane, 2-cyclohexyl-2-(2-triisopropylsilylethyl)-l,3- diisopentoxypropane, 2-cyclohexyl-2-(2-triphenylsilylethyl)-l,3-diethoxypropane, 2- cy cl ohexyl-2-(2 -methyldiphenylsilylethyl)- 1,3 -di ethoxypropane, 2-cyclohexyl-2-(2- dimethylphenylsilylethyl)-l,3-diethoxypropane, 2-cyclohexyl-2-(2-(tris(4- chlorophenyl)silyl)ethyl)-l,3-dibutoxypropane, 2-cyclohexyl-2-(2-(bis(4- chlorophenyl)(methyl)silyl)ethyl)-l,3-dibutoxypropane, 2-cyclohexyl-2-isopentyl-l-ethoxy-3- methoxy-propane, 2-cyclohexyl-2-(3, 3 -difluorobutyl)- 1 -ethoxy-3 -methoxy-propane, 2- cy cl ohexyl-2-(3, 3 -dibromobutyl)- 1 -ethoxy-3 -methoxy -propane, 2-cyclohexyl-2-(3,3- dichlorobutyl)- 1 -ethoxy-3 -methoxy-propane, 2-cy clohexyl-2-(3 ,3 , 3 -trifluoropropyl)- 1 - ethoxy-3 -methoxy-propane, 2-cy clohexyl-2-(3 ,3 , 3 -tribromopropyl)- 1 -ethoxy-3 -methoxy- propane, 2-cyclohexyl-2-(3,3,3-trichloropropyl)-l-methoxy-3-allyloxy- propane, 2-cyclohexyl-

2-(3 ,3 -difluoropropyl)- 1 -ethoxy-3 -methoxy-propane, 2-cy clohexyl-2-(3 , 3 -dibromopropyl)- 1 - ethoxy-3 -methoxy-propane, 2-cy clohexyl-2-(3, 3 -di chloropropyl)- 1 -ethoxy-3 -methoxy- propane, 2-cyclohexyl-2-(3,3-dichloro-3-fluoro-propyl)-l-isobutoxy-3- methoxy-propane, 2- cyclohexyl-2-(3,3-dichloro-3-bromo-propyl)-l-ethoxy-3-methox y-propane, 2-cyclohexyl-2- (3 ,3 -difluoro-3 -bromo-propyl)- 1 -ethoxy-3 -isopentoxy-propane, 2-cyclohexyl-2-(3 ,3 -difluoro-

3 -chloro-propyl)- 1 -ethoxy-3 -methoxy -propane, 2-cyclohexyl-2-(3,3-difluoro-5-methylhexyl)-

1 -ethoxy-3 -methoxy-propane, 2-cyclohexyl-2-(3,3-dichloro-5-methylhexyl)-l-ethoxy-3- methoxy-propane, 2-cyclohexyl-2-(3-chloro-3-isobutyl-5-methylhexyl)-l -ethoxy-3 -methoxy- propane, 2-cyclohexyl-2-(3-bromo-3-isobutyl-5-methylhexyl)-l-ethoxy-3 -propoxy -propane,

2-cyclohexyl-2-(3-fluoro-3-isobutyl-5-methylhexyl)-l-etho xy-3-methoxy-propane, 2- cyclohexyl-2-(3-fluoro-3-isopentyl-6-methylheptyl)-l -ethoxy-3 -methoxy -propane, 2- cyclohexyl-2-(3-chloro-3-isopentyl-6-methylheptyl)-l-ethoxy- 3-methoxy-propane, 2- cyclohexyl-2-(3-bromo-3-isopentyl-6-methylheptyl)-l-ethoxy-3 -methoxy-propane, 2- cy cl ohexyl-2-(3, 3 -diphenylbutyl)- 1 -ethoxy-3 -methoxy-propane, 2-cyclohexyl-2-(3,3- diphenylpropyl)- 1 -ethoxy-3 -methoxy-propane, 2-cy clohexyl-2-(3 , 3 ,3 -triphenylpropyl)- 1 - ethoxy-3 -methoxy-propane, 2-cyclohexyl-2-(3,3,3-tris(4-chlorophenyl)propyl)-l-ethoxy-3 - methoxy -propane, 2-cyclohexyl-2-(3,3-dimethylbutyl)-l-ethoxy-3-methoxy-propan e, 2- cyclohexyl-2-(3 -methylpentyl)- 1 -ethoxy-3 -methoxy -propane, 2-cyclohexyl-2-(3-ethylpentyl)- 1 -ethoxy-3 -methoxy -propane, 2-cy cl ohexyl-2-(3, 3 -di ethylpentyl)- 1 -ethoxy-3 -methoxy- propane, 2-cyclohexyl-2-(3-isopropyl-4-methylpentyl)-l-ethoxy-3-metho xy-propane, 2- cy cl ohexyl-2-(3,3-diisopropyl-4-methylpentyl)-l -ethoxy-3 -methoxy-propane, 2-cyclohexyl-2- (cyclohexylethyl)-l-methoxy-3 -propoxy -propane, 2-cyclohexyl-2-(cyclopentylethyl)-l- ethoxy-3 -methoxy-propane, 2-cyclohexyl-2-(phenethyl)-l -ethoxy-3 -methoxy-propane, 2- cyclohexyl-2-(2-trimethylsilylethyl)-l -ethoxy-3 -methoxy -propane, 2-cyclohexyl-2-(2- triisopropylsilylethyl)-l-allyloxy-3-methoxy-propane, 2-cyclohexyl-2-(2-triphenylsilylethyl)-

1 -ethoxy-3 -methoxy -propane, 2-cyclohexyl-2-(2-methyldiphenylsilylethyl)-l-ethoxy-3- methoxy-propane, 2-cyclohexyl-2-(2-dimethylphenylsilylethyl)-l -ethoxy-3 -methoxy-propane,

2-cyclohexyl-2-(2-(tris(4-chlorophenyl)silyl)ethyl)-l-eth oxy-3-isobutoxy -propane, 2- cyclohexyl-2-(2-(bis(4-chlorophenyl)(methyl)silyl)ethyl)-l-e thoxy-3-methoxy -propane, 2-(3- methylcyclohexyl)-2-isopentyl-l,3-dimethoxypropane, 2-(2-methylcyclohexyl)-2-(3,3- difluorobutyl)- 1 ,3 -dimethoxypropane, 2-(4-methylcy clohexyl)-2-(3 , 3 -dibromobutyl)- 1,3- dimethoxypropane, 2-(4-methylcyclohexyl)-2-(3,3-dichlorobutyl)-l,3-dimethoxypr opane, 2- (2-methylcyclohexyl)-2-(3,3,3-trifluoropropyl)-l,3-dimethoxy propane, 2-(4- methylcyclohexyl)-2-(3,3,3-tribromopropyl)-l,3-dimethoxyprop ane, 2-(2-methylcyclohexyl)- 2-(3, 3, 3-tri chloropropyl)- 1,3-dimethoxypropane, 2-(4-methylcyclohexyl)-2-(3,3- difluoropropyl)- 1,3 -dimethoxypropane, 2-(3-methylcyclohexyl)-2-(3,3-dibromopropyl)-l,3- dimethoxypropane, 2-(4-methylcyclohexyl)-2-(3,3-dichloropropyl)-l,3-dimethoxyp ropane, 2-

(4-methylcy cl ohexyl)-2-(3, 3 -di chi oro-3 -fluoro-propyl)- 1,3 -di ethoxypropane, 2-(2- methylcy cl ohexyl)-2-(3, 3 -di chi oro-3 -bromo-propyl)- 1,3 -dipropoxypropane, 2-(4- methylcy clohexyl)-2-(3 ,3 -difluoro-3 -bromo-propyl)- 1 , 3 -dibutoxypropane, 2-(4- methylcy cl ohexyl)-2-(3, 3 -difluoro-3 -chloro-propyl)- 1,3 -dipropoxypropane, 2-(4- methylcyclohexyl)-2-(3,3-difluoro-5-methylhexyl)-l,3-diethox ypropane, 2-(4- methylcyclohexyl)-2-(3,3-dichloro-5-methylhexyl)-l,3-dipropo xypropane, 2-(4- methylcyclohexyl)-2-(3-chloro-3-isobutyl-5-methylhexyl)-l,3- diisopentoxypropane, 2-(4- methylcy cl ohexyl)-2-(3-bromo-3-isobutyl-5-methylhexyl)-l,3-di ethoxypropane, 2-(3- methylcyclohexyl)-2-(3-fluoro-3-isobutyl-5-methylhexyl)-l,3- dipropoxypropane, 2-(4- methylcyclohexyl)-2-(3-fluoro-3-isopentyl-6-methylheptyl)-l, 3-diethoxypropane, 2-(3- methylcyclohexyl)-2-(3-chloro-3-isopentyl-6-methylheptyl)-l, 3-dibutoxypropane, 2-(4- methylcyclohexyl)-2-(3-bromo-3-isopentyl-6-methylheptyl)-l,3 -dipropoxypropane, 2-(4- methylcy cl ohexyl)-2-(3, 3 -diphenylbutyl)- 1,3-dimethoxypropane, 2-(4-methylcyclohexyl)-2- (3 , 3 -diphenylpropyl)- 1 , 3 -dimethoxypropane, 2-(4-methylcy clohexyl)-2-(3 ,3,3- triphenylpropyl)- 1,3 -dimethoxypropane, 2-(4-methylcyclohexyl)-2-(3,3,3-tris(4- chlorophenyl)propyl)-l -ethoxy-3 -methoxy-propane, 2-(2 -methylcy cl ohexyl)-2-(3, 3- dimethylbutyl)- 1,3-dimethoxypropane, 2-(4-methylcy cl ohexyl)-2-(3 -methylpentyl)- 1,3- dimethoxypropane, 2-(4-methylcyclohexyl)-2-(3-ethylpentyl)-l,3-dimethoxypropan e. 2-(4- methylcy cl ohexyl)-2-(3,3-di ethylpentyl)- 1,3-dimethoxypropane, 2-(4-methylcyclohexyl)-2- (3-isopropyl-4-methylpentyl)-l,3-dimethoxypropane, 2-(4-methylcyclohexyl)-2-(3,3- diisopropyl-4-methylpentyl)-l,3-dimethoxypropane, 2-(4-methylcyclohexyl)-2-

(cyclohexylethyl)- 1,3 -dimethoxypropane, 2-(3 -methylcy cl ohexyl)-2-(cy cl opentylethyl)- 1,3- dimethoxypropane, 2-(4-methylcy cl ohexyl)-2-(phenethyl)- 1,3 -dimethoxypropane, 2-(3- methylcy cl ohexyl)-2-(2 -trimethylsilylethyl)- 1,3-dimethoxypropane, 2-(3 -methylcy clohexyl)-

2-(2-triisopropylsilylethyl)-l,3-dimethoxypropane, 2-(4-methylcyclohexyl)-2-(2- triphenylsilylethyl)-l,3-dimethoxypropane, 2-(4-methylcyclohexyl)-2-(2- methyldiphenylsilylethyl)-l-ethoxy-3-methoxy-propane, 2-(4-methylcyclohexyl)-2-(2- dimethylphenylsilylethyl)- l-ethoxy-3-methoxy-propane, 2-(4-methylcyclohexyl)-2-(2-(tris(4- chlorophenyl)silyl)ethyl)-l-ethoxy-3-isobutoxy -propane, 2-(3-methylcyclohexyl)-2-(2-(bis(4- chlorophenyl)(methyl)silyl)ethyl)-l -ethoxy-3 -methoxy -propane, 2-(3,5-dimethylcyclohexyl)- 2-isopentyl- 1,3-dimethoxypropane, 2-(4-(tert-butyl)cyclohexyl)-2-(3,3-difluorobutyl)-l,3- dimethoxypropane, 2-(2-isopropyl-5-methylcyclohexyl)-2-(3,3-dibromobutyl)-l,3- dimethoxypropane, 2-(2-isopropyl-5-methylcyclohexyl)-2-(3,3-dichlorobutyl)-l,3 - dimethoxypropane, 2-(4-(tert-butyl)cyclohexyl)-2-(3,3,3-trifluoropropyl)-l,3- dimethoxypropane, 2-(2-isopropyl-5-methylcyclohexyl)-2-(3,3,3-tribromopropyl)- l,3- dimethoxypropane, 2-cyclohexyl-2-(3,4-dimethylpentyl)- 1,3 -dimethoxypropane, 2- cyclohexyl-2-(3,4,4-trimethylpentyl)-l,3-dimethoxypropane, 2-cyclohexyl-2-(3,5- dimethylhexyl)- 1,3 -dimethoxypropane, 2-cy cl ohexyl-2-(3 -cyclopropylbutyl)- 1,3- dimethoxypropane, 2-cyclohexyl-2-(3,3-dicyclohexylpropyl)-l,3-dimethoxypropane , 2- cy cl ohexyl-2-(3 -phenylbutyl)- 1,3 -dimethoxypropane, 2-cyclohexyl-2-(3-methyl-4,4,4- trifluorobutyl)- 1,3-dimethoxypropane, 2-cyclohexyl-2-(3-trifluoromethyl-4,4,4- trifluorobutyl)- 1,3-dimethoxypropane, 2-cy cl ohexyl-2-(3-benzyl-4, 4, 4-trifluorobutyl)- 1,3- dimethoxypropane, 2-cyclohexyl-2-((2,6-dimethyl)cyclohexylethyl)-l,3-dimethoxy propane, 2-cy clohexyl-2-((3, 3, 5-trimethyl)cy cl ohexylethyl)- 1,3-dimethoxypropane, 2-cyclohexyl-2-(2- (l,7,7-trimethylbicyclo[3.1.1]heptan-6-yl)ethyl)-l,3-dimetho xypropane, 2-cyclohexyl-2-(3,3- dibenzylpropyl)- 1,3 -dimethoxypropane, 2-cyclohexyl-2-(9-fluorenylethyl)-l,3- dimethoxypropane, 2-(4-methylcyclohexyl)-2-isopentyl-l,3-dimethoxypropane, 2-cyclohexyl- 2-(3 -methylhexyl)- 1 ,3 -dimethoxypropane, 2-(4-methylcy clohexyl)-2-(3 -methylhexyl)- 1,3- dimethoxypropane, 2-cyclohexyl-2-(3,3,3-triphenylpropyl)-l,3-dimethoxypropane, 2-(4-(tert- butyl)cyclohexyl)-2-(3,3,3-trichloropropyl)-l,3-dimethoxypro pane, 2-(2-isopropyl-5- methylcy cl ohexyl)-2-(3, 3 -difluoropropyl)- 1,3 -dimethoxypropane, 2-(3,5- dimethylcyclohexyl)-2-(3,3-dibromopropyl)-l,3-dimethoxypropa ne, 2-(2-isopropyl-5- methylcy cl ohexyl)-2-(3, 3 -di chloropropyl)- 1,3 -dimethoxypropane, 2-(2-isopropyl-5- methylcyclohexyl)-2-(3,3-dichloro-3-fluoro-propyl)-l,3-dieth oxypropane, 2-(4-(tert- butyl)cyclohexyl)-2-(3,3-dichloro-3-bromo-propyl)-l,3-diprop oxypropane, 2-(2-isopropyl-5- methylcy cl ohexyl)-2-(3 ,3 -difluoro-3 -bromo-propyl)- 1 , 3 -dibutoxypropane, 2-(2-isopropyl-5- methylcy cl ohexyl)-2-(3, 3 -difluoro-3 -chloro-propyl)- 1,3 -dipropoxypropane, 2-(2-isopropyl-5- methylcy cl ohexyl)-2-(3,3-difluoro-5-methylhexyl)-l,3-di ethoxypropane, 2-(2-isopropyl-5- methylcy cl ohexyl)-2-(3,3-di chi oro-5-methylhexyl)-l,3-dipropoxypropane, 2-(2-isopropyl-5- methylcyclohexyl)-2-(3-chloro-3-isobutyl-5-methylhexyl)-l,3- diisopentoxypropane, 2-(2- isopropyl-5-methylcyclohexyl)-2-(3-bromo-3-isobutyl-5-methyl hexyl)-l,3-diethoxypropane, 2-(3,5-dimethylcyclohexyl)-2-(3-fluoro-3-isobutyl-5-methylhe xyl)-l,3-dipropoxypropane, 2- (2-isopropyl-5-methylcyclohexyl)-2-(3-fluoro-3-isopentyl-6-m ethylheptyl)-l,3- diethoxypropane, 2-(3,5-dimethylcyclohexyl)-2-(3-chloro-3-isopentyl-6-methylh eptyl)-l,3- dibutoxypropane, 2-(2-isopropyl-5-methylcyclohexyl)-2-(3-bromo-3-isopentyl-6- methylheptyl)- 1 ,3 -dipropoxypropane, 2-(2-isopropyl-5-methylcyclohexyl)-2-(3,3- diphenylbutyl)- 1 ,3 -dimethoxypropane, 2-(2-isopropyl-5-methylcyclohexyl)-2-(3,3- diphenylpropyl)- 1 , 3 -dimethoxypropane, 2-(2-isopropyl-5-methylcyclohexyl)-2-(3,3,3- triphenylpropyl)- 1 ,3 -dimethoxypropane, 2-(2-isopropyl-5-methylcyclohexyl)-2-(3,3,3-tris(4- chlorophenyl)propyl)- 1 -ethoxy-3 -methoxy-propane, 2-(4-(tert-butyl)cyclohexyl)-2-(3,3- dimethylbutyl)- 1 , 3 -dimethoxypropane, 2-(2-isopropyl-5-methylcyclohexyl)-2-(3- methylpentyl)- 1,3 -dimethoxypropane, 2-(2-isopropyl-5-methylcyclohexyl)-2-(3-ethylpentyl)- 1,3 -dimethoxypropane, 2-(2-isopropyl-5-methylcyclohexyl)-2-(3,3-diethylpentyl)-l,3 - dimethoxypropane, 2-(2-isopropyl-5-methylcyclohexyl)-2-(3-isopropyl-4-methylpe ntyl)-l,3- dimethoxypropane, 2-(2-isopropyl-5-methylcyclohexyl)-2-(3,3-diisopropyl-4-meth ylpentyl)- 1,3 -dimethoxypropane, 2-(2-isopropyl-5-methylcyclohexyl)-2-(cyclohexylethyl)-l,3- dimethoxypropane, 2-(3,5-dimethylcyclohexyl)-2-(cyclopentylethyl)-l,3-dimethox ypropane, 2-(2-isopropyl-5-methylcyclohexyl)-2-(phenethyl)-l,3-dimetho xypropane, 2-(3,5- dimethylcy cl ohexyl)-2-(2 -trimethyl silylethyl)- 1,3 -dimethoxypropane, 2-(3,5- dimethylcyclohexyl)-2-(2-triisopropylsilylethyl)-l,3-dimetho xypropane, 2-(2-isopropyl-5- methylcy cl ohexyl)-2-(2-triphenylsilylethyl)-l,3-dimethoxypropane, 2-(2-isopropyl-5- methylcyclohexyl)-2-(2-methyldiphenylsilylethyl)-l-ethoxy-3- methoxy-propane, 2-(2- isopropyl-5-methylcyclohexyl)-2-(2-dimethylphenylsilylethyl) -l-ethoxy-3-methoxy-propane, 2-(2-isopropyl-5-methylcyclohexyl)-2-(2-(tris(4-chlorophenyl )silyl)ethyl)-l-ethoxy-3- isobutoxy -propane, 2-(3,5-dimethylcyclohexyl)-2-(2-(bis(4-chlorophenyl)(methyl) silyl)ethyl)- 1 -ethoxy-3 -methoxy -propane.

[0016] Preferably, the molar ratio between the electron donor of formula (I) and the Ti atoms in the final solid catalyst component ranges from 0.3 : 1 to 1.5 : 1 and more preferably from 0.4: 1 to 1.3: 1.

[0017] Preferably, the molar ratio between the Mg atoms and the electron donor of formula (I) in the final solid catalyst component ranges from 2.5: 1 to 50.0: 1, more preferably 3: 1 to 45.0: 1, more preferably 5.0:1 to 30.0: 1 and especially more preferably from 6.0:1 to 25.0: 1.

[0018] Additional electron donors may in principle be present in the catalyst component of the present disclosure. Preferably, they are selected from mono or diesters of aromatic or aliphatic carboxylic acids. More preferably, they are selected from esters of aliphatic dicarboxylic acids such as malonates, succinates and glutarates as described in WO99/57160. Additional donors may be present in an amount from 0.1 to up less than 50.0%mol, preferably from 0.5 to 45.0% based on the total molar amount of difunctional electron donors. If the additional donor is different from esters of aliphatic dicarboxylic acids its amount is preferably less than 10% mol and more preferably less than 8%mol based on the total molar amount of electron donors.

[0019] Preferably, the solid catalyst component is endowed with a porosity determined by mercury method relating to pore with radius equal to or less than 1 pm of at least 0.20 cm ³ /g. More preferably, the porosity is higher than 0.30 cm ³ /g and especially higher than 0.40 cm ³ /g. [0020] Preferably, the said catalyst component has an average particle size ranging from 20 to 150pm and more preferably from 40 to 100 pm.

[0021] As explained above, the catalyst component of the invention comprises, in addition to the above electron donors, a titanium compound having at least a Ti-halogen bond and a Mg halide. The preferred titanium compounds used in the catalyst component of the present invention are TiCh and TiCh; furthermore, also Ti-haloalcoholates of formula Ti(OR ⁵ )n- _y X _y can be used, where n is the valence of titanium, y is a number between 1 and n-1, X is halogen and R ⁵ is a hydrocarbon radical having from 1 to 10 carbon atoms.

[0022] The preparation of the solid catalyst component can be carried out according to several methods. According to a preferred method, the solid catalyst component can be prepared by reacting a titanium compound of formula Ti(0R ⁵ )m- _y X _y , where m is the valence of titanium and y is a number between 1 and m, preferably TiCh, with a magnesium chloride deriving from an adduct of formula MgCh’pR/’OH, where p is a number between 0.1 and 6, preferably from 2 to 3.5, and R ⁶ is a hydrocarbon radical having 1-18 carbon atoms. The adduct can be suitably prepared in spherical form by mixing alcohol and magnesium chloride in the presence of an inert hydrocarbon immiscible with the adduct, operating under stirring conditions at the melting temperature of the adduct (100-130°C). Then, the emulsion is quickly quenched, thereby causing the solidification of the adduct in form of spherical particles. Examples of spherical adducts prepared according to this procedure are described in USP 4,399,054 and USP 4,469,648. The so obtained adduct can be directly reacted with Ti compound or it can be previously subjected to thermal controlled dealcoholation (80-130°C) so as to obtain an adduct in which the number of moles of alcohol is lower than 3, preferably between 0.1 and 2.5 and even more preferably between 0.5 and 2.3.

[0023] The catalyst based on the electron donor of formula (I) of the present disclosure is able to offer very good performances even when it is prepared starting from highly dealcoholated adducts, for example having a number of mole of alcohol per mole of Mg lower than 2. When using these dealcoholated adducts, the diether donors of the prior art are fixed in a much lower extent and the deriving catalyst offers deteriorated performances.

[0024] In the preferred method of producing the catalyst of the invention, the reaction with the Ti compound can be carried out by suspending the adduct (dealcoholated or as such) in cold TiCh generally at 0°C. Preferably the adduct is used in an amount such as to have a concentration ranging from 20 to 100 g/1, and preferably from 30 to 90 g/1. According to a preferred embodiment, the electron donor (I) is added to the system at the beginning of this stage of reaction and preferably when the temperature of the mixture is in the range of 10°C to 60°C. The electron donor (I) is fed in amounts such as to meet the desired molar ratio in the final catalyst. In an embodiment the Mg/donor (I) molar ratio may range from 2: 1 to 25: 1, preferably 2:1 to 25: 1, more preferably from 2: 1 to 15: 1 and especially from 3: 1 to 10: 1. The temperature is then gradually raised up until reaching a temperature ranging from 90-130°C and kept at this temperature for 0.5-3 hours.

After completing the reaction time stirring is stopped, the slurry is let to settle, and liquid phase removed. A second stage of treatment with TiCh is performed, preferably carried out at a temperature ranging from 70 to 130°C. After completing the reaction time, stirring is stopped, the slurry is let to settle, and liquid phase removed. It is possible, although not necessary, to carry out additional reaction stage with the titanium compound and preferably with TiCh under the same conditions described above and in the absence of electron donors. The so obtained solid can then be washed with liquid hydrocarbon under mild conditions and then dried. The catalyst based on the electron donor of formula (I) of the present disclosure is able to offer very good performances even when it is prepared with relatively high Mg/ID molar ratios (13- 20) and the amount of ID fixed on the catalyst is such that the molar ratio ID/Ti in the range 0.3-0.6. When used in the same Mg/ID high ratio, the diether donors of the prior art are fixed in a much lower extent and the deriving catalyst offers deteriorated performances.

[0025] The solid catalyst component may also contain a small amounts of additional metal compounds selected from those containing elements belonging to group 1-15 preferably groups 11-15 of the periodic table of elements (lupac version).

[0026] Most preferably, said compounds, which do not contain metal-carbon bonds, include elements selected from Cu, Zn, and Bi. Preferred compounds are the oxides, carbonates, alkoxylates, carboxylates and halides of said metals. Among them, ZnO, ZnCh, CuO, CuCh, and Cu diacetate, BiCh, Bi carbonates and Bi carboxylates are preferred. BiCh, Bi carbonates and Bi carboxylates are especially preferred.

[0027] The said compounds can be added either during the preparation of the previously described magnesium-alcohol adduct or they can be introduced into the catalysts by dispersing them into the titanium compound in liquid form which is then reacted with the adduct.

Whichever the method used, the final amount of said metals into the final catalyst component ranges from 0.1 to 10%wt, preferably from 0.3 to 8% and most preferably from 0.5 to 5% wt with respect to the total weight of solid catalyst component.

[0028] The solid catalyst components according to the present invention are converted into catalysts for the polymerization of olefins by reacting them with organoaluminum compounds according to known methods.

[0029] In particular, it is an object of the present invention a catalyst for the polymerization of olefins CH2=CHR, in which R is hydrogen or a hydrocarbon radical with 1-12 carbon atoms, comprising the product obtained by contacting:

(i) the solid catalyst component as disclosed above and

(ii) an alkylaluminum compound and, optionally,

(iii) an external electron donor compound.

[0030] The alkyl-Al compound (ii) is preferably chosen among the trialkyl aluminum compounds such as for example triethylaluminum, triisobutylaluminum, tri-n-butylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum. It is also possible to use alkylaluminum halides, alkylaluminum hydrides or alkylaluminum sesquichlorides, such as AIEt2Cl and AhEtsCh, possibly in mixture with the above cited trialkylaluminum compounds. [0031] The catalyst component of the present disclosure provide a highly stereoregular polypropylene even when polymerizing in the absence of external donor. This is evidenced by the amount of xylene insoluble fraction which can be higher than 97.5%wt and preferably higher than 98%wt. It has to be noted that the above mentioned stereoregular polypropylene is obtained in very high yields. In particular, when polymerizing in liquid propylene at 70°C for two hours the polymerization activity is higher than 100 kg _po i/gcat more preferably higher than 115 kgpoi/gcat. In some cases the activity can be even higher than 130 kg _po i/gcat.

[0032] If used, suitable external electron-donor compounds (iii) include silicon compounds, ethers, esters, amines, heterocyclic compounds and particularly 2,2,6,6-tetramethylpiperidine and ketones.

[0033] Another class of preferred external donor compounds is that of silicon compounds of formula (R ⁷ ) _a (R ⁸ )bSi(OR ⁹ ) _c , where a and b are integers from 0 to 2, c is an integer from 1 to 4 and the sum (a+b+c) is 4; R ⁷ , R ⁸ , and R ⁹ , are alkyl, cycloalkyl or aryl radicals with 1-18 carbon atoms optionally containing heteroatoms. Particularly preferred are the silicon compounds in which a is 1, b is 1, c is 2, at least one of R ⁷ and R ⁸ is selected from branched alkyl, cycloalkyl or aryl groups with 3-10 carbon atoms optionally containing heteroatoms and R ⁹ is a Ci-Cio alkyl group, in particular methyl. Examples of such preferred silicon compounds are methylcyclohexyldimethoxysilane (C donor), diphenyldimethoxysilane, methyl-t- butyldimethoxysilane, dicyclopentyldimethoxysilane (D donor), diisopropyldimethoxysilane, (2-ethylpiperidinyl)t-butyldimethoxysilane, (2-ethylpiperidinyl)thexyldimethoxysilane, (3,3,3- trifluoro-n-propyl)(2-ethylpiperidinyl)dimethoxysilane, methyl(3,3,3-trifluoro-n- propyl)dimethoxysilane. Moreover, are also preferred the silicon compounds in which a is 0, c is 3, R ⁸ is a branched alkyl or cycloalkyl group, optionally containing heteroatoms, and R ⁹ is methyl. Examples of such preferred silicon compounds are cyclohexyltrimethoxysilane, t- butyltrimethoxysilane and thexyltrimethoxysilane.

[0034] The external electron donor compound (iii) is used in such an amount to give a molar ratio between the organoaluminum compound and said electron donor compound (iii) of from 0.1 : 1 to 500: 1, preferably from 1 : 1 to 300: 1 and more preferably from 3: 1 to 100: 1.

[0035] Therefore, it constitutes a further object of the present invention a process for the (co)polymerization of olefins CH2=CHR, in which R is hydrogen or a hydrocarbonradical with 1-12 carbon atoms, carried out in the presence of a catalyst comprising the product of the reaction between:

(i) the solid catalyst component of the invention;

(ii) an alkylaluminum compound and, (iii) optionally an electron-donor compound (external donor).

[0036] The polymerization process can be carried out according to known techniques for example slurry polymerization using as diluent an inert hydrocarbon solvent, or bulk polymerization using the liquid monomer (for example propylene) as a reaction medium. Moreover, it is possible to carry out the polymerization process in gas-phase operating in one or more fluidized or mechanically agitated bed reactors.

[0037] The catalyst of the present invention can be used as such in the polymerization process by introducing it directly into the reactor. In a preferred embodiment, the catalyst can be pre-polymerized before being introduced into the first polymerization reactor. The term prepolymerized as used in the art, means a catalyst which has been subject to a polymerization step at a low conversion degree. According to the present invention a catalyst is considered to be pre-polymerized when the amount the polymer produced is from about 0.1 up to about 1000 g per gram of solid catalyst component.

[0038] The pre-polymerization can be carried out with the a-olefins selected from the same group of olefins disclosed before. In particular, it is especially preferred pre-polymerizing ethylene or mixtures thereof with one or more a-olefins in an amount up to 20% by mole. Preferably, the conversion of the pre-polymerized catalyst component is from about 0.2 g up to about 500 g per gram of solid catalyst component.

[0039] The pre-polymerization step can be carried out at temperatures from 0° to 80°C preferably from 5° to 50°C in liquid or gas-phase. The pre-polymerization step can be performed in-line as a part of a continuous polymerization process or separately in a batch process. The batch pre-polymerization of the catalyst of the invention with ethylene in order to produce an amount of polymer ranging from 0.5 to 20 g per gram of catalyst component is particularly preferred.

[0040] The polymerization is generally carried out at temperature ranging from 20 to 120°C, preferably from40 to 80°C. When the polymerization is carried out in gas-phase the operating pressure is generally between 0.5 and 5 MPa, preferably between 1 and 4 MPa. In the bulk polymerization the operating pressure is generally between 1 and 8 MPa, preferably between 1.5 and 5 MPa.

[0041] The preferred alpha-olefins to be (co)polymerized are ethylene, propylene, 1- butene, 4-methyl-l -pentene and 1 -hexene. In particular, the above described catalysts can be used in the (co)polymerization of propylene and ethylene to prepare different kinds of products in particular of propylene homo and copolymers. In view of the high activity and stereospecificity the catalyst of the present disclosure can be advantageously used in the preparation of low xylene soluble content propyl ene/ethylene copolymers and high purity polypropylene polymers having a very low content of halogen (Cl) and metals like Ti, Mg and Al. In particular, when employed in the preparation of propylene/ethylene copolymers with an ethylene content ranging from 0.1 to 6%wt based on the total weight of propylene and ethylene, the catalyst of the present disclosure are able to provide copolymers with a low amount of xylene soluble material.

[0042] These catalysts are also suitable for producing high impact resistance polymer compositions comprising (A) a crystalline propylene homo or copolymer matrix and a substantial amount, in certain applications more than 50%wt, of (B) a low crystallinity, highly soluble in xylene, propylene-ethylene based copolymer.

[0043] Such polymer compositions are preferably prepared in a multistep process comprising at least two different polymerization stages carried out in different reactors. Usually the first step, in which the crystalline propylene homo or copolymer is prepared, can be carried out either in gas-phase or in liquid phase. The gas-phase polymerization can be carried out in a fluidized or stirred, fixed bed reactor or in a gas-phase reactor comprising two interconnected polymerization zones one of which, working under fast fluidization conditions and the other in which the polymer flows under the action of gravity. The liquid phase process can be either in slurry, solution or bulk (liquid monomer). This latter technology is the most preferred and can be carried out in various types of reactors such as continuous stirred tank reactors, loop reactors or plug-flow ones. Preferably, the first step is carried out in gas-phase. In this stage and/or in the successive stage, hydrogen can be used as a molecular weight regulator.

[0044] In the second stage of the polymerization process, the propylene-ethylene copolymer (B) is produced preferably in a conventional fluidized-bed gas-phase reactor in the presence of the polymeric material and the catalyst system coming from the preceding polymerization step.

[0045] The polymer produced in this stage may contain from 15 to 75%wt of ethylene, optionally containing minor proportions of a diene, and it solubility in xylene at 25°C may be at least 60%wt. .

[0046] The following examples are given to illustrate and not to limit the invention itself.

CHARACTERIZATION

Determination of porosity.

[0047] Porosity and surface area with mercury: the measurement is carried out using a Pascal 140-240 series porosimeter by Carlo Erba. The porosity is determined by intrusion of mercury under pressure. For this determination a calibrated dilatometer (capillary diameter 3 mm) CD3P (by Carlo Erba) is used, that is connected to a reservoir of mercury and to a high-vacuum pump. A weighed amount of sample is placed in the dilatometer. The apparatus is then placed under high vacuum and is maintained in these conditions for ca. 20 minutes. The dilatometer is then connected to the mercury reservoir and the mercury is allowed to slowly fill the dilatometer, until it reaches the level marked on the dilatometer at a height of 10 cm. The valve that connects the dilatometer to the vacuum pump is closed and then the mercury pressure is gradually increased with nitrogen up to 100 kPa. Subsequently, the calibrated dilatometer is transferred into an autoclave with oil for high pressure in order to reach pressure values up to 200 MPa. Under the effect of the pressure, the mercury enters into the pores of the particles and the mercury level decreases accordingly. The porosity (cm ³ /g), the pore distribution curve and the average pore size are directly calculated from the integral pore distribution curve, which is a function of both the volume reduction of the mercury and the applied pressure values. All these data are provided and elaborated by the porosimeter associated computer which is equipped with dedicated software supplied by Carlo Erba. After calculation, the average pores radius is given as weighted average of the single average pores radius contribution for each interval of porosity.

Determination of X.L

[0048] About 2.5 grams of polymer and 250 ml of o-xylene were placed in a round-bottom flask provided with a cooler and a reflux condenser and kept under nitrogen. The obtained mixture was heated to 135°C and was kept under stirring for about 60 minutes. The final solution was allowed to cool to 25°C under continuous stirring, and the insoluble polymer was then filtered. The filtrate was then evaporated in a nitrogen flow at 140°C to reach a constant weight. The content of said xylene-soluble fraction is expressed as a percentage of the original 2.5 grams and then, by difference, the X.I. %.

Determination of donors.

[0049] The content of electron donor was determined via gas-chromatography. Determination of Melt flow rate (MFR).

[0050] The melt flow rate MIL of the polymer was determined according to ISO 1133 (230 ⁰ C, 2.16 Kg).

Determination of comonomer.

[0051] The content of comonomer (ethylene) has been determined via NMR spectroscopy. Determination of Tm

Determined by differential scanning calorimetry (DSC), weighting 6 ±1 mg, is heated to 220 ±1° C at a rate of 20 °C/min and kept at 220 ±1° C for 2 minutes in nitrogen stream and it is thereafter cooled at a rate of 20° C/min to 40 ±2° C, thereby kept at this temperature for 2 min to crystallise the sample. Then, the sample is again fused at a temperature rise rate of 20° C/min up to 220° C ±1. The melting scan is recorded, a thermogram is obtained, and, from this, melting temperatures and crystallization temperatures are read.

Determination of Intrinsic Viscosity (I. V.)

[0052] On the xylene soluble fraction, the Intrisic Viscosity was measured. The sample is dissolved in tetrahydronaphthalene at 135 °C and then is poured into the capillary viscometer. The viscometer tube (Ubbelohde type) is surrounded by a cylindrical glass jacket; this setup allows temperature control with a circulating thermostated liquid. The downward passage of the meniscus is timed by a photoelectric device.

The passage of the meniscus in front of the upper lamp starts the counter which has a quartz crystal oscillator. The meniscus stops the counter as it passes the lower lamp and the efflux time is registered: this is converted into a value of intrinsic viscosity through Huggins' equation (Huggins, M.L., J. Am. Chem. Soc., 1942, 64, 2716) provided that the flow time of the pure solvent is known at the same experimental conditions (same viscometer and same temperature). One single polymer solution is used to determine [q].

Determination of Flexural Modulus

[0053] Flexural Modulus is measured according to ISO 178 and ISO 1873-2

Determination of Tensile Modulus

Tensile Modulus is measured according to ISO 527 and ISO 1873-2

Determination of Charpy

[0054] Charpy impact test according to ISO 179-leA, and ISO 1873-2

Determination of ¹³ C NMR spectra of propylene/ethylene copolymers

[0055] The ¹³ C NMR spectra of the heterophasic copolymers and of their XI and XS fractions were acquired on a Bruker AV-600 spectrometer equipped with cryoprobe, operating at 160.91 MHz in the Fourier transform mode at 120°C.

The peak of the Spp carbon (nomenclature according to "Monomer Sequence Distribution in Ethylene-Propylene Rubber Measured by ¹³ C NMR. 3. Use of Reaction Probability Mode " C. J. Carman, R. A. Harrington and C. E. Wilkes, Macromolecules, 1977, 10, 536) was used as internal reference at 29.9 ppm. The samples were dissolved in 1, 1,2,2- tetrachloroethane-d2 at 120°C with a 8 % wt/v concentration. Each spectrum was acquired with a 90° pulse, 15 seconds of delay between pulses and CPD to remove 1H-13C coupling. 512 transients were stored in 32K data points using a spectral window of 9000 Hz.

[0056] The assignments of the spectra, the evaluation of triad distribution and the composition were made according to Kakugo ("Carbon- 13 NMR determination of monomer sequence distribution in ethyl ene-propylene copolymers prepared with 5-titanium trichloridediethylaluminum chloride" M. Kakugo, Y. Naito, K. Mizunuma and T. Miyatake, Macromolecules, 1982, 15, 1150) using the following equations:

PPP = 100 Tpp / S PPE = 100 Tpg / S EPE = 100 T _5S / S

PEP = 100 Spp / S PEE = 100 Spg / S EEE = 100 (0.25 S _Y g + 0.5 S _5s ) / S

S = Tpp + Tpg + Tgg + Spp + Spg + 0.25 S _Y g + 0.5 Sgg

[0057] The molar percentage of ethylene content was evaluated using the following equation:

E% mol = 100 x [PEP+PEE+EEE]

[0058] The weight percentage of ethylene content was evaluated using the following equation:

E %wt = 100 x MWE x E% mol / (MWE X E% mol + MWp x P% mol) where P% mol is the molar percentage of propylene content, while MWE and MWp are the molecular weights of ethylene and propylene, respectively.

EXAMPLES

General procedure for the preparation of MgCh*pEtOH adducts.

[0059] An initial amount of microspheroidal MgCh*2.8EtOH was prepared according to the method described in Example 2 of USP 4,399,054 but operating at 3,000 rpm instead of 10,000. A portion of the so obtained adduct was then subject to thermal dealcoholation at increasing temperatures from 30 to 130°C operating in nitrogen current until the molar alcohol content per mol of Mg is 2.1.

Preparation of electron donors

Synthesis of 2-cyclohexyl-2-isopentyl-l,3-dimethoxypropane

Step 1 : synthesis of diethyl 2-cyclohexylmalonate

[0060] To a 1 L round bottom flask equipped with mechanical stirrer, thermometer and condenser is added ethanol (400 mL) and potassium tert-butoxide (50 g, 0.4 mol). Successively, di ethylmal onate (63 g, 0.4 mol) is added dropwise in 10 minutes observing the formation of white suspension. The temperature is raised to76°C and cyclohexyl bromide is added over a period of 30 minutes. The mixture is left at reflux for 40 hours, then the solvent is removed under vacuum and the slurry recovered with ethyl acetate (200 mL). The organic phase is washed with water (2x100 mL) and 10% NaHCCh, then evaporated, thus leading to 26 g of diethyl 2-cyclohexylmalonate as a light yellow oil, purity 99% (GC), yield 27%. ¹ HNMR (5, 400 MHz, CDCh): 4.2 (q, 4H, OCHi), 3.2 (d, 1H, CH malonic), 2.1 (m, 1H, CH cyclohexyl), 1.8-0.8 (m, 16H, OCH2CH3 + cyclohexyl.

Step 2: synthesis of diethyl 2-cyclohexyl-2-isopentylmalonate

[0061] To a 500 mL round bottom flask equipped with mechanical stirrer, thermometer and condenser is added tetrahydrofuran (120 mL), diethyl 2-cyclohexylmalonate (26 g, 105 mmol) and sodium hydride (95%, 3 g, 119 mmol). The temperature is raised to 40°C, observing formation of gas. After 1 hour the gas evolution disappears, then isopentyl bromide (20 g, 130 mmol) is added over a period of 30 minutes. The mixture is left at reflux for 25 hours, then diluted with 300 mL of HC1 1 M. The organic phase is diluted with diethyl ether (200 mL), washed with water (2x100 mL), then evaporated, thus leading to 23 g of diethyl 2-cyclohexyl- 2-isopentylmalonate as a light yellow oil, purity 95% (GC), yield 67%. ¹ HNMR (5, 400 MHz, CDCh): 4.1 (q, 4H, OCH2), 1.7 (m, 3H, CH cyclohexyl + a-CJ/2 isopentyl), 1.6-1.3 (m, 8H, cyclohexyl), 1.2 (m, 7H, OCH2C//3 + ~i-CH isopentyl), 1.0 (m, 4H, cyclohexyl + P-C//2 isopentyl), 0.8 (d, 6H, (CH?)2 isopentyl).

Step 3: synthesis of 2-cyclohexyl-2-isopentyl-l ,3-propandiol

[0062] To a 500 mL round bottom flask equipped with mechanical stirrer, thermometer and condenser is added tetrahydrofuran (100 mL), diethyl 2-cyclohexyl-2-isopentylmalonate (95%, 23 g, 70 mmol) and lithium aluminum hydride (95 %, 3 g, 77 mmol). The mixture is left at reflux for 16 hours, then diluted with 200 mL of HC1 1 M. The organic phase extracted with diethyl ether (200 mL), washed with water (2x100 mL), then evaporated, thus leading to 15 g of 2-cyclohexyl-2-isopentylmalonate-l,3-propandiol as colorless viscous oil, purity 98% (GC), yield 92%. ¹ HNMR (5, 400 MHz, CDCh): 4.9-4.6 (dd, 4H, OCHi), 2.2 (s, 2H, OH), 1.9-1.1 (m, 16H, cyclohexyl + isopentyl), 0.9 (d, 6H, (CH?)2 isopentyl).

Step 4: synthesis of 2-cyclohexyl-2-isopentyl-l,3-dimethoxypropane

[0063] To a 500 mL round bottom flask equipped with mechanical stirrer, thermometer and condenser is added tetrahydrofuran (70 mL), 2-cyclohexyL2-isopentyl-l,3-propandiol (98%, 15 g, 64 mmol) and sodium hydride (95%, 3 g, 128 mmol). The temperature is raised to 40°C (gas evolution) and methyl iodide (20 g, 141 mmol) is added dropwise in 1 hour. Successively, the slurry is left at 40°C for 8 hours, then diluted with 200 mL of HC1 1 M. The organic phase diluted with diethyl ether (100 mL), washed with water (2x50 mL), then evaporated, thus leading to 16 g of 2-cyclohexyl-2-isopentyl-l,3-dimethoxypropane as a colourless oil, purity 99% (GC), yield 98%. ¹ HNMR (5, 400 MHz, CDCh): 3.2 (s, 6H, C/LO), 3.1 (s, 4H, OCHi), 1.8-1.0 (m, 16H, cyclohexyl + isopentyl), 0.8 (d, 6H, (CH ₃ )2 isopentyl).

Synthesis of 2-cydohexyl-2-(3,3,3-trifluoro-n-propyl)-l,3-dimethoxypropan e

Step 1 : synthesis of diethyl 2-cyclohexyl-2-(3,3,3-trifluoro-n-propyl)malonate

[0064] This derivative is prepared according to the synthesis described in Example 1 - step

2. using l-iodo-3,3,3-trifluoro-n-propane as alkylating agent. The product is a light yellow oil with a purity of 97%, yield 50%. ¹ HNMR (5, 400 MHz, CDCh): 4.2 (q, 4H, OCHi), 2.2-1.5 (m, 10H, cyclohexyl + 3,3,3-trifluoro-n-propyl), 1.2 (t, 6H, OCH2C7/ ₃ ), 1.1-0.9 (m, 5H, cyclohexyl + 3,3,3-trifluoro-n-propyl).

Step 2: synthesis of 2-cyclohexyl-2-(3,3,3-trifluoro-n-propyl)-l,3-propandiol

[0065] This derivative is prepared according to the synthesis described in Example 1 - step

3. The product is an orange viscous oil with a purity of 98.5%, yield 92%. ¹ HNMR (5, 400 MHz, CDCh): 3.7-3.5 (dd, 4H, OCH2), 2.5 (s, 2H, OH), 2.0 (m, 2H, P-C//2 3,3,3-trifluoro-n- propyl), 1.8-0.9 (m, 13H, cyclohexyl + 3,3,3-trifluoro-n-propyl).

Step 3: synthesis of 2-cyclohexyl-2-(3, 3, 3-trifluoro-n-propyl)-l,3-dimethoxypropane

[0066] This derivative is prepared according to the synthesis described in Example 1 - step

4. The product is a yellow oil with a purity of 98%, yield 95%. ¹ HNMR (5, 400 MHz, CDCh): 3.2 (s, 6H, CHO), 3.1 (s, 4H, OCH2), 2.1 (m, 2H, P-C//2 3,3,3-trifluoro-n-propyl), 1.8-0.9 (m, 13H, cyclohexyl + 3,3,3-trifluoro-n-propyl).

Synthesis of 2-cyclohexyl-2-(3-methylpentyl)-l,3-dimethoxypropane

Step 1 : synthesis of diethyl 2-cyclohexyl-2-(3-methylpentyl)malonate

[0067] This derivative is prepared according to the synthesis described in Example 1 - step

2, using l-bromo-3 -methylpentane as alkylating agent. The product is a colorless oil with a purity of 92%, yield 82%. ¹ HNMR (5, 400 MHz, CDCh): 4.2 (q, 4H, OCH2), 2.1-1.5 (m, 8H, cyclohexyl + 3 -methylpentyl), 1.3 (t, 6H, OCH2C7/ ₃ ), 1.2-0.8 (m, 16H, cyclohexyl + 3- methylpentyl).

Step 2: synthesis of 2-cyclohexyl-2-(3-methylpentyl)-l,3-propandiol

[0068] This derivative is prepared according to the synthesis described in Example 1 - step

3. The product is an yellow viscous oil with a purity of 92%, yield 92%. ¹ HNMR (5, 400 MHz, CDCh): 3.7-3.5 (dd, 4H, OCH2), 2.7 (s, 2H, OH), 1.6-0.8 (m, 24H, cyclohexyl + 3- methylpentyl).

Step 3: synthesis of 2 -cyclohexy 1-2 -(3 -methylpentyl) -1,3 -dimethoxypropane [0069] This derivative is prepared according to the synthesis described in Example 1 - step 4. The product is distilled with a Vigreaux apparatus at 145°C/6 mmHg, obtaining a colorless oil with a purity of 96%, yield 81%. ¹ HNMR (5, 400 MHz, CDCh): 3.3 (s, 6H, C//3O), 3.2 (s, 4H, OC//2), 1.8-1.0 (m, 18H, cyclohexyl + 3 -methylpentyl), 0.8 (m, 6H, 3 -methylpentyl).

Synthesis of Synthesis of 2-cyclohexyl-2-(3-ethylpentyl)-l,3-dimethoxypropane

Step 1 : synthesis of diethyl 2-cyclohexyl-2-(3-ethylpentyl)malonate

[0070] This derivative is prepared according to the synthesis described in Example 1 - step

2, using l-bromo-3 -ethylpentane as alkylating agent. The product is a yellow oil with a purity of 87%, yield 77%. ¹ HNMR (5, 400 MHz, CDCh): 4.2 (q, 4H, OCH2), 2.1-1.5 (m, 8H, cyclohexyl + 3 -ethylpentyl), 1.2 (t, 6H, OCH2CH3), 1.1-0.8 (m, 18H, cyclohexyl + 3- ethylpentyl).

Step 2: synthesis of 2-cyclohexyl-2-(3-ethylpentyl)-l,3-propandiol

[0071] This derivative is prepared according to the synthesis described in Example 1 - step

3. The product is an colorless viscous oil with a purity of 86%, yield 95%. ¹ HNMR (5, 400 MHz, CDCh): 3.7-3.5 (dd, 4H, OCH2), 2.2 (s, 2H, OH), 1.6-0.8 (m, 26H, cyclohexyl + 3- ethylpentyl).

Step 3: synthesis of 2 -cyclohexy 1-2 -(3 -ethylpentyl) -1,3 -dimethoxypropane

This derivative is prepared according to the synthesis described in Example 1 - step 4. The product is a colorless oil with a purity of 95%, yield 86%. ¹ HNMR (5, 400 MHz, CDCh): 3.2 (s, 6H, C//3O), 3.1 (s, 4H, OCH2), 1.8-1.0 (m, 20H, cyclohexyl + 3 -ethylpentyl), 0.8 (m, 6H, 3- ethylpentyl).

Synthesis of 2-cyclohexyl-2-(3,5-dimethylhexyl)-l,3-dimethoxypropane

Step 1 : synthesis of diethyl 2 -cyclohexy 1-2 -(3, 5 -dime thy lhexyl)malonate

[0072] This derivative is prepared according to the synthesis described in Example 1 - step

2, using l-bromo-3, 5 -dimethylhexane as alkylating agent. The product is a brown oil with a purity of 92%, yield 78%. ¹ HNMR (5, 400 MHz, CDCh): 4.2 (q, 4H, OCH2), 1.9-1.3 (m, 10H, cyclohexyl + 3, 5 -dimethylhexyl), 1.2 (t, 6H, OCH2C//3), 1.1-0.8 (m, 8H, cyclohexyl + 3,5- dimethylhexyl), 0.7 (m, 10H, 3,5-dimethylhexyl).

Step 2: synthesis of 2-cyclohexyl-2-(3,5-dimethylhexyl)-l,3-propandiol

[0073] This derivative is prepared according to the synthesis described in Example 1 - step

3. The product is an yellow viscous oil with a purity of 96%, yield 96%. ¹ HNMR (5, 400 MHz, CDCh): 3.7-3.5 (dd, 4H, OCH2), 2.3 (s, 2H, OH), 1.7-0.8 (m, 18H, cyclohexyl + 3,5- dimethylhexyl), 0.7 (m, 10H, 3,5-dimethylhexyl).

Step 3: synthesis of 2-cyclohexyl-2-(3,5-dimethylhexyl)-l ,3-dimethoxypropane [0074] This derivative is prepared according to the synthesis described in Example 1 - step 4. The product is a colorless oil with a purity of 96%, yield 94%. ¹ HNMR (5, 400 MHz, CDCh): 3.3 (s, 6H, C// O), 3.2 (s, 4H, OC//2), 1.8-0.9 (m, 18H, cyclohexyl + 3, 5 -dimethylhexyl), 0.7 (m, 10H, 3, 5 -dimethylhexyl).

[0075]

Synthesis of 2-cyclohexyl-2-n-pentyl-l,3-dimethoxypropane

Step 1 : synthesis of diethyl 2-cyclohexyl-2-n-pentylmalonate

[0076] This derivative is prepared according to the synthesis described in Example 1 - step

2. using n-pentyl bromide as alkylating agent. The product is a light yellow oil with a purity of 90%, yield 80%. ¹ HNMR (5, 400 MHz, CDCh): 4.1 (q, 4H, OCH), 1.9-1.6 (m, 8H, cyclohexyl + n-pentyl), 1.4-0.9 (m, 17H, OCH2C//3 + cyclohexyl + n-pentyl), 0.8 (t, 3H, CH n-pentyl).

Step 2: synthesis of 2 -cyclohexy 1-2 -n-pentyl- 1,3 -propandiol

[0077] This derivative is prepared according to the synthesis described in Example 1 - step

3. The product is an colorless viscous oil with a purity of 98%, yield 75%. ¹ HNMR (5, 400 MHz, CDCh): 3.9-3.7 (dd, 4H, OCH), 2.2 (s, 2H, OH), 1.8-1.0 (m, 19H, cyclohexyl + n- pentyl), 0.9 (t, 3H, CH n-pentyl).

Step 3 : synthesis of 2 -cyclohexy 1-2 -n-pentyl- 1 , 3-dimethoxypropane

[0078] This derivative is prepared according to the synthesis described in Example 1 - step

4. The product is a colorless oil with a purity of 98%, yield 96%. ¹ HNMR (5, 400 MHz, CDCh): 3.3 (s, 6H, CHO), 3.2 (s, 4H, OCH), 1.8-1.0 (m, 19H, cyclohexyl + n-pentyl), 0.9 (t, 3H, CH n-pentyl).

Synthesis of 2-cyclohexyl-2-n-butyl-l, 3-dimethoxypropane

Step 1 : synthesis of diethyl 2-cyclohexyl-2-n-butylmalonate

[0079] This derivative is prepared according to the synthesis described in Example 1 - step

2, using n-butyl bromide as alkylating agent. The product is a light yellow oil with a purity of 96%, yield 79%. ¹ HNMR (5, 400 MHz, CDCh): 4.1 (q, 4H, OCH), 1.9-1.6 (m, 8H, cyclohexyl + n-butyl), 1.4-0.9 (m, 15H, OCH2C//3 + cyclohexyl + n-butyl), 0.8 (t, 3H, CH n-butyl).

Step 2: synthesis of 2 -cyclohexy 1-2 -n-butyl- 1,3 -propandiol

[0080] This derivative is prepared according to the synthesis described in Example 1 - step

3. The product is an colorless viscous oil with a purity of 99%, yield 85%. ¹ HNMR (5, 400 MHz, CDCh): 3.9-3.7 (dd, 4H, OCH), 2.2 (s, 2H, OH), 1.8-1.0 (m, 17H, cyclohexyl + n-butyl), 0.9 (t, 3H, CH n-butyl).

Step 3 : synthesis of 2-cyclohexyl-2-n-butyl-l, 3-dimethoxypropane [0081] This derivative is prepared according to the synthesis described in Example 1 - step 4. The product is a colorless oil with a purity of 98%, yield 99%. ¹ HNMR (5, 400 MHz, CDCh): 3.3 (s, 6H, C//3O), 3.2 (s, 4H, OCH2), 1.8-1.1 (m, 17H, cyclohexyl + n-butyl), 0.9 (t, 3H, CH3 n-butyl).

Synthesis of 2-cyclohexyl-2-isobutyl-l,3-dimethoxypropane

Step 1 : synthesis of diethyl 2-cyclohexyl-2-isobutylmalonate

[0082] This derivative is prepared according to the synthesis described in Example 1 - step

2. using isobutyl bromide as alkylating agent. The product is a light yellow oil with a purity of 92%, yield 80%. ¹ HNMR (5, 400 MHz, CDCh): 4.1 (q, 4H, OCH2), 1.9-1.6 (m, 8H, cyclohexyl + n-butyl), 1.4-0.9 (m, 12H, OCH2C//3 + cyclohexyl + n-butyl), 0.8 (d, 6H, (C f isobutyl).

Step 2: synthesis of 2-cyclohexyl-2-isobutyl-l ,3-propandiol

[0083] This derivative is prepared according to the synthesis described in Example 1 - step

3. The product is an colorless viscous oil with a purity of 88%, yield 84%. ¹ HNMR (5, 400 MHz, CDCh): 3.9-3.7 (dd, 4H, OCH2), 2.3 (s, 2H, OH), 1.8-1.0 (m, 14H, cyclohexyl + isobutyl), 0.9 (d, 6H, (CHf isobutyl).

Step 3: synthesis of 2-cyclohexyl-2-isobutyl-l ,3 -dimethoxypropane

[0084] This derivative is prepared according to the synthesis described in Example 1 - step

4. The final product, purified by distillation (115°C/0.5 mmHg), is a colorless oil with a purity of 98%, yield 75%. ¹ HNMR (5, 400 MHz, CDCh): 3.3 (s, 6H, CH3O), 3.3 (s, 4H, OCH2), 1.8- 1.1 (m, 14H, cyclohexyl + isobutyl), 0.9 (d, 6H, (CHf isobutyl).

Synthesis of 2-cyclopentyl-2-isopentyl-l,3-dimethoxypropane

Step 1 : synthesis of diethyl 2-cyclopentylmalonate

[0085] This derivative is prepared according to the synthesis described in Example 1 - step

1, using cyclopentyl bromide as alkylating agent. The product is a colorless oil with a purity of 99%, yield 56%. ¹ HNMR (5, 400 MHz, CDCh): ¹ HNMR (5, 400 MHz, CDCh): 4.2 (q, 4H, OCH2), 3.2 (d, 1H, CH malonic), 2.2 (m, 1H, CH cyclopentyl), 1.7-0.8 (m, 14H, OCH2C//3 + cyclopentyl).

Step 2: synthesis of diethyl 2-cyclopentyl-2-isopentylmalonate

[0086] This derivative is prepared according to the synthesis described in Example 1 - step

2, using isobutyl bromide as alkylating agent. The product is a light yellow oil with a purity of 92%, yield 80%. ¹ HNMR (5, 400 MHz, CDCh): 4.1 (q, 4H, OCH2), 2.4 (m, 3H, CH cyclopentyl + a-CHi isopentyl), 1.6-1.3 (m, 8H, cyclopentyl), 1.2-1.0 (m, 9H, OCH2CH3 + isopentyl), 0.8 (d, 6H, (CH ₃ ) ₂ isopentyl).

Step 3: synthesis of 2 -cy clopenty 1-2 -isopentyl- 1 ,3-propandiol [0087] This derivative is prepared according to the synthesis described in Example 1 - step

3. The product is an colorless viscous oil with a purity of 97%, yield 90%. ¹ HNMR (5, 400 MHz, CDCh): 3.8-3.6 (dd, 4H, CH2), 2.4 (s, 2H, H), 1.7-1.0 (m, 14H, cyclopentyl + isopentyl), 0.9 (d, 6H, (Ci isopentyl).

Step 4: synthesis of 2-cyclopentyl-2-isopentyl-l ,3 -dimethoxypropane

[0088] This derivative is prepared according to the synthesis described in Example 1 - step

4. The final product is a colorless oil with a purity of 98%, yield 92%. ¹ HNMR (5, 400 MHz, CDCh): 3.3 (s, 6H, C//3O), 3.3 (s, 4H, OCH2), 1.8-1.1 (m, 14H, cyclopentyl + isopentyl), 0.9 (d, 6H, (CH )2 isopentyl).

Preparation of solid catalyst component - general procedure.

[0089] Into a 1000 mL four-necked round flask, purged with nitrogen, 500 mL of TiCL were introduced at 0°C. While stirring, 20 grams of the microspheroidal MgCh-2. lEtOH adduct (prepared as described above) were added. Then, an amount of electron donor of formula (I) such as to have a Mg/Donor of 6 were charged at 0°C.

The temperature was raised to 100°C and kept at this value for 120 minutes. After, the stirring was stopped, the liquid siphoned off and the treatment with TiCh was repeated at 120°C for 60 minutes. After sedimentation and siphoning the solid was washed with anhydrous i-hexanes (6 x 100 ml) and dried to obtain a free flowing powder. The characterization of the so obtained solid catalytic component is reported in Table 1.

General procedure for the homo-polymerization of propylene in bulk

[0090] A 4— liter steel autoclave equipped with a stirrer, pressure gauge, thermometer, catalyst feeding system, monomer feeding lines and thermostating jacket, was purged with nitrogen flow at 70°C for one hour. Then, at 30°C under propylene flow, were charged in sequence: 75 ml of anhydrous hexane containing 0.76 g of AlEt3, about 6 mg of solid catalyst component and when used, the external donor (type and amount reported in the tables). The autoclave was closed and subsequently 2NL of hydrogen was added. Then, under stirring, 1.2 kg of liquid propylene were fed. The temperature was raised to 70°C in ten minutes and the polymerization was carried out at this temperature for two hours, was added At the end of the polymerization, the non-reacted propylene was removed; the polymer was recovered and dried in an oven at 80°C.

[0091] Examples 1-5 and comparative examples 6-10. Polymerization of propylene.

[0092] Catalysts of inventive examples 1-5 and comparative examples 6-9 were prepared in accordance with the general procedure described above, using donors described in Table 1. The catalyst characterization and the results of the bulk polymerization of propylene is reported in Table 1.

[0093] Table 1.

Examples 11-16

Catalyst preparation

Into a 1000 mL four-necked round flask, purged with nitrogen, 500 mL of TiCh were introduced at -3°C. While stirring, 20 grams of the microspheroidal MgC12-2.1EtOH adduct (prepared as described above) were added. Then, for some of the preparations indicated in Table 2, an amount of BiCh to have a Mg/BiCh of 60 mr was charged at -3°C.

In all preparations the temperature was raised to 100°C and kept at this value for 30 minutes. After, the stirring was stopped and the liquid siphoned off, fresh TiCh and 2-cyclohexyl-2- isopentyl-l,3-dimethoxypropane as internal donor were added to have the Mg/ID reported in table 2 and the temperature was raised at 120°C under stirring for 30 minutes. After stopping the stirring, the liquid was siphoned off and the treatment with TiCh was repeated at 120°C for 15 minutes . After sedimentation and siphoning the solid was washed with anhydrous i- hexanes (6 x 200 ml) and dried to obtain a free flowing powder. Details on the catalyst preparation, characterization and the results of the bulk polymerization of propylene are reported in Table 2.

Comparative example 17

Catalyst preparation

The catalyst preparation was carried out as described in example 16 with the difference that 9,9-bis(methoxymethyl)fluorene was used instead of 2-cyclohexyl-2-isopentyl-l,3- dimethoxypropane as internal donor. Details on the catalyst preparation, characterization and the results of the bulk polymerization of propylene are reported in Table 2.

Table 2

TEAL/C Donor molar ratio 20

Example 18

An initial amount of microspheroidal MgCh 2.8C2H5OH was prepared according to the method described in Example 2 of USP 4,399,054 but operating at 3,000 rpm instead of 10,000. The so obtained adduct having an average particle size of 87 pm was then subject to thermal dealcoholation at increasing temperatures from 30 to 130°C operating in nitrogen current until the molar alcohol content per mol of Mg is 1.16. Using this support, the catalyst was prepared and tested in accordance with the general procedures already described. Details on the catalyst preparation, characterization and the results of the bulk polymerization of propylene are reported in Table 3. Comparative example 19

The catalyst preparation was carried out as described in example 18 with the difference that 9,9-bis(methoxymethyl)fluorene was used instead of 2-cyclohexyl-2-isopentyl-l,3- dimethoxypropane as internal donor. Details on the catalyst preparation, characterization and the results of the bulk polymerization of propylene are reported in Table 3.

Table 3

TEALZED molar ratio =4