Catalyst components for the polymerization of olefins

Abstract

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 and at least two electron donor compounds one being selected from a specific class of 1,3-diethers and the other from diester organic compounds are endowed with high polymerization activity and stereospecificity even in the absence of external donors.

Description

CATALYST COMPONENTS FOR THE POLYMERIZATION OF OLEFINSFIELD 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 two electron donor compounds selected from specific classes.BACKGROUND OF THE INVENTION

[0002] Catalyst components for the stereospecific polymerization of olefins have been disclosed in the art. In 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-diether 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 high polymerization activity and a high stereospecificity even when the external donor is absent. In addition to that, it would be also desirable that the catalyst be able to show good performances at low level of the most critical components, i.e., the 1,3-diether internal donor.

[0005] The applicant has surprisingly found that the above mentioned needs can be satisfied by properly combining a specific group of 1,3-diethers with another type of internal donors.SUMMARY OF THE INVENTION

[0006] Accordingly, one of the objects of the present disclosure relates to a solid catalyst component comprising a magnesium halide, a titanium compound having at least a Ti-halogen bond and at least two electron donor compounds one of which (ID1) being selected from 1,3 di ethers of formula (I)in which R1and R2are, independently, C1-C5 alkyl groups, X is Si or C, R3and R4groups, independently, are selected from hydrogen, C1-C20 hydrocarbon groups and halogens with the proviso that at least two R3are not hydrogen and the other (ID2) being selected from organic compounds bearing two ester groups, said solid catalyst component being further characterized by the fact that the molar ratio between ID2 and ID1 (ID2 / ID1) is equal to, or higher than, 1.0.DETAILED DESCRIPTION OF THE INVENTION

[0007] Preferably in the ID1 of formula (I), R1and R2are 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, alkylaryl and also hydrocarbon groups fused together to form saturated or unsaturated cycles.

[0009] Preferably, R4groups, 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 R4groups 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 R4groups are hydrogen are also preferred.

[0010] R3groups are preferably selected from hydrogen and C1-C10 hydrocarbon groups and halogens. When R3is 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 R3is 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 R3is a hydrogen, a C1-C20 hydrocarbon group or halogen, Preferably, the hydrocarbon group is selected from C1-C4 linear orbranched alkyl groups more preferably from methyl. Most preferred are the structures in which one R3is selected from hydrogen and the remaining two from methyl groups.

[0013] Another group of preferred structures are those in which X is carbon and R3is 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 R3are selected from F and more preferably those in which all the R3groups are F.

[0014] According to another preferred embodiment, X is Si and R3is 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 R3groups are selected from methyl.

[0015] Specific examples of compounds of formula (I) that can be advantageously used include:2-cy cl ohexyl-2-isopentyl- 1,3 -dimethoxypropane, 2-cyclohexyl-2-(3,3-difluorobutyl)-l,3- dimethoxypropane, 2-cyclohexyl-2-(3,3-dibromobutyl)-l,3-dimethoxypropane, 2-cyclohexyl-2-(3,3- dichlorobutyl)-l,3-dimethoxypropane, 2-cyclohexyl-2-(3,3,3-trifluoropropyl)-l,3- dimethoxypropane, 2-cyclohexyl-2-(3,3,3-tribromopropyl)-l,3-dimethoxypropane, 2-cyclohexyl-2- (3,3,3-trichloropropyl)-l,3-dimethoxypropane, 2-cy clohexyl-2-(3, 3 -difluoropropyl)- 1,3- dimethoxypropane, 2-cyclohexyl-2-(3,3-dibromopropyl)-l,3-dimethoxypropane, 2-cyclohexyl-2- (3, 3 -di chloropropyl)- 1,3 -dimethoxypropane, 2-cyclohexyl-2-(3,3-dichloro-3-fluoro-propyl)-l,3- dimethoxypropane, 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)-l,3-dimethoxypropane, 2-cyclohexyl-2-(3,3-difluoro-3-chloro-propyl)-l,3-dimethoxypropane, 2-cyclohexyl-2-(3,3-difluoro-5-methylhexyl)-l,3- dimethoxypropane, 2-cy clohexyl-2-(3,3-di chi oro-5-methylhexyl)-l,3-dimethoxypropane, 2- cyclohexyl-2-(3-chloro-3-isobutyl-5-methylhexyl)-l,3-dimethoxypropane, 2-cyclohexyl-2-(3- bromo-3-isobutyl-5-methylhexyl)-l,3-dimethoxypropane, 2-cyclohexyl-2-(3-fluoro-3-isobutyl-5- methylhexyl)- 1,3 -dimethoxypropane, 2-cyclohexyl-2-(3-fluoro-3-isopentyl-6-methylheptyl)-l,3- dimethoxypropane, 2-cyclohexyl-2-(3-chloro-3-isopentyl-6-methylheptyl)-l,3-dimethoxypropane, 2-cyclohexyl-2-(3-bromo-3-isopentyl-6-methylheptyl)-l,3-dimethoxypropane, 2-cyclohexyl-2-(3,3- diphenylbutyl)- 1 , 3 -dimethoxypropane, 2-cy clohexyl-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)- 1,3 -dimethoxypropane, 2-cy cl ohexyl-2-(3, 3 -dimethylbutyl)- 1,3- dimethoxypropane, 2-cyclohexyl-2-(3-methylpentyl)-l,3-dimethoxypropane, 2-cyclohexyl-2-(3- ethylpentyl)-l,3-dimethoxypropane, 2-cyclohexyl-2-(3,3-diethylpentyl)-l,3-dimethoxypropane, 2- cyclohexyl-2-(3-isopropyl-4-methylpentyl)-l,3-dimethoxypropane, 2-cyclohexyl-2-(3,3- diisopropyl-4-methylpentyl)-l,3-dimethoxypropane, 2-cyclohexyl-2-(cyclohexylethyl)-l,3- dimethoxypropane, 2-cyclohexyl-2-(cyclopentylethyl)-l,3-dimethoxypropane, 2-cyclohexyl-2-(phenethyl)- 1,3 -dimethoxypropane, 2-cyclohexyl-2-(2-trimethylsilylethyl)-l,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-dimethoxypropane, 2- cyclohexyl-2-(2-(tris(4-chlorophenyl)silyl)ethyl)- 1,3 -dimethoxypropane, 2-cyclohexyl-2-(2-(bis(4- chlorophenyl)(methyl)silyl)ethyl)-l,3-dimethoxypropane, 2-cyclohexyl-2-isopentyl-l,3- diallyloxypropane, 2-cyclohexyl-2-(3,3-difluorobutyl)-l,3-diethoxypropane, 2-cyclohexyl-2-(3,3- dibromobutyl)- 1,3 -diallyloxypropane, 2-cyclohexyl-2-(3,3-dichlorobutyl)-l,3-diethoxypropane, 2- cyclohexyl-2-(3, 3, 3 -trifluoropropyl)- 1,3 -di ethoxypropane, 2-cyclohexyl-2-(3,3,3-tribromopropyl)- 1,3-diethoxypropane, 2-cyclohexyl-2-(3,3,3-trichloropropyl)-l,3-dipropoxypropane, 2-cyclohexyl- 2-(3, 3 -difluoropropyl)- 1,3 -diallyloxypropane, 2-cy clohexyl-2-(3, 3 -dibromopropyl)- 1,3- diethoxypropane, 2-cyclohexyl-2-(3,3-dichloropropyl)-l,3-dipropoxypropane, 2-cyclohexyl-2-(3,3- dichloro-3-fluoro-propyl)-l,3-diethoxypropane, 2-cy cl ohexyl-2-(3, 3 -di chi oro-3 -bromo-propyl)- 1,3- dipropoxypropane, 2-cyclohexyl-2-(3,3-difluoro-3-bromo-propyl)-l,3-dibutoxypropane, 2- cyclohexyl-2-(3, 3 -difluoro-3 -chloro-propyl)- 1,3 -dipropoxypropane, 2-cyclohexyl-2-(3,3-difluoro-5- methylhexyl)- 1,3 -di ethoxypropane, 2-cyclohexyl-2-(3,3-dichloro-5-methylhexyl)-l,3- dipropoxypropane, 2-cyclohexyl-2-(3-chloro-3-isobutyl-5-methylhexyl)-l,3-diisopentoxypropane, 2-cy cl ohexyl-2-(3-bromo-3-isobutyl-5-methylhexyl)-l,3-di ethoxypropane, 2-cyclohexyl-2-(3- fluoro-3-isobutyl-5-methylhexyl)-l,3-dipropoxypropane, 2-cyclohexyl-2-(3-fluoro-3-isopentyl-6- methylheptyl)-l,3-diethoxypropane, 2-cyclohexyl-2-(3-chloro-3-isopentyl-6-methylheptyl)-l,3- dibutoxypropane, 2-cyclohexyl-2-(3-bromo-3-isopentyl-6-methylheptyl)-l,3-dipropoxypropane, 2- cyclohexyl-2-(3, 3 -diphenylbutyl)- 1,3 -diallyloxypropane, 2-cy cl ohexyl-2-(3, 3 -diphenylpropyl)- 1,3- 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-cy cl ohexyl-2-(3, 3 -dimethylbutyl)- 1,3- di ethoxypropane, 2-cyclohexyl-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-diethoxypropane, 2-cyclohexyl-2-(3,3-diisopropyl- 4-methylpentyl)- 1,3 -di ethoxypropane, 2-cyclohexyl-2-(cyclohexylethyl)-l,3-diethoxypropane, 2- cyclohexyl-2-(cyclopentylethyl)-l,3-diallyloxypropane, 2-cyclohexyl-2-(phenethyl)-l,3- diisopentoxypropane, 2-cy cl ohexyl-2-(2 -trimethylsilylethyl)- 1,3 -dibutoxypropane, 2-cyclohexyl-2- (2-triisopropylsilylethyl)-l,3-diisopentoxypropane, 2-cyclohexyl-2-(2-triphenylsilylethyl)-l,3- diethoxypropane, 2-cyclohexyl-2-(2-methyldiphenylsilylethyl)-l,3-diethoxypropane, 2-cyclohexyl- 2-(2-dimethylphenylsilylethyl)-l,3-diethoxypropane, 2-cyclohexyl-2-(2-(tris(4- chlorophenyl)silyl)ethyl)- 1,3 -dibutoxypropane, 2-cyclohexyl-2-(2-(bis(4-chlorophenyl)(methyl)silyl)ethyl)-l,3-dibutoxypropane, 2-cyclohexyl-2-isopentyl-l-ethoxy-3- methoxy-propane, 2-cy clohexyl-2-(3, 3 -difluorobutyl)- 1 -ethoxy-3 -methoxy -propane, 2-cyclohexyl- 2-(3, 3 -dibrom obutyl)-l -ethoxy-3 -methoxy-propane, 2-cyclohexyl-2-(3,3-dichlorobutyl)-l-ethoxy-3- methoxy-propane, 2-cy clohexyl-2-(3 ,3 , 3 -trifluoropropyl)- 1 -ethoxy-3 -methoxy-propane, 2- cyclohexyl-2-(3,3,3-tribromopropyl)-l-ethoxy-3-methoxy-propane, 2-cyclohexyl-2-(3,3,3- trichloropropyl)-l-methoxy-3 -allyloxy-propane, 2-cy clohexyl-2-(3, 3 -difluoropropyl)- 1 -ethoxy-3 - methoxy-propane, 2-cy clohexyl-2-(3, 3 -dibrom opropyl)-l -ethoxy-3 -methoxy-propane, 2- cyclohexyl-2-(3, 3 -di chi oropropyl)-l -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 -methoxy -propane, 2-cy clohexyl-2-(3 , 3 -difluoro-3 -bromo-propyl)- 1 -ethoxy-3 -i sopentoxy- propane, 2-cyclohexyl-2-(3,3-difluoro-3-chloro-propyl)-l-ethoxy-3-methoxy-propane, 2- cyclohexyl-2-(3,3-difluoro-5-methylhexyl)-l -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- m ethylhexyl)- 1 -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-ethoxy-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-cyclohexyl-2- (3, 3 -diphenylbutyl)- 1 -ethoxy-3 -methoxy-propane, 2-cy cl ohexyl-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)- 1 -ethoxy-3 -methoxy-propane, 2-cy clohexyl-2-(3 -methylpentyl)- 1 -ethoxy-3 - methoxy-propane, 2-cyclohexyl-2-(3 -ethylpentyl)- 1 -ethoxy-3 -methoxy-propane, 2-cyclohexyl-2- (3, 3 -di ethylpentyl)- 1 -ethoxy-3 -methoxy-propane, 2-cyclohexyl-2-(3-isopropyl-4-methylpentyl)-l- ethoxy-3 -methoxy -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)-l- 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-ethoxy-3-isobutoxy-propane, 2-cyclohexyl-2-(2-(bis(4- chlorophenyl)(methyl)silyl)ethyl)-l -ethoxy-3 -methoxy-propane, 2-(3-methylcyclohexyl)-2- i sopentyl- 1 , 3 -dimethoxypropane, 2-(2-methylcy clohexyl)-2-(3 , 3 -difluorobutyl)- 1,3-dimethoxypropane, 2-(4-methylcyclohexyl)-2-(3,3-dibromobutyl)-l,3-dimethoxypropane, 2-(4- methylcyclohexyl)-2-(3,3-di chlorobutyl)- 1,3-dimethoxypropane, 2-(2-methylcyclohexyl)-2-(3,3,3- trifluoropropyl)- 1 ,3 -dimethoxypropane, 2-(4-methylcy clohexyl)-2-(3 , 3 ,3 -tribromopropyl)- 1,3- dimethoxypropane, 2-(2-methylcy cl ohexyl)-2-(3, 3, 3-tri chloropropyl)- 1,3-dimethoxypropane, 2-(4- methylcyclohexyl)-2-(3,3-difluoropropyl)- 1,3-dimethoxypropane, 2-(3 -methylcy cl ohexyl)-2-(3, 3- dibromopropyl)- 1,3 -dimethoxypropane, 2-(4-methylcyclohexyl)-2-(3,3-dichloropropyl)-l,3- dimethoxypropane, 2-(4-methylcyclohexyl)-2-(3,3-dichloro-3-fluoro-propyl)-l,3-diethoxypropane, 2-(2-methylcyclohexyl)-2-(3,3-dichloro-3-bromo-propyl)-l,3-dipropoxypropane, 2-(4- methylcyclohexyl)-2-(3,3-difluoro-3-bromo-propyl)-l,3-dibutoxypropane, 2-(4-methylcyclohexyl)- 2-(3, 3 -difluoro-3 -chloro-propyl)- 1,3 -dipropoxypropane, 2-(4-methylcyclohexyl)-2-(3,3-difluoro-5- methylhexyl)- 1 , 3 -diethoxypropane, 2-(4-methylcyclohexyl)-2-(3,3-dichloro-5-methylhexyl)-l,3- dipropoxypropane, 2-(4-methylcyclohexyl)-2-(3-chloro-3-isobutyl-5-methylhexyl)-l,3- diisopentoxypropane, 2-(4-methylcyclohexyl)-2-(3-bromo-3-isobutyl-5-methylhexyl)-l,3- diethoxypropane, 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-methylcyclohexyl)-2-(3,3-diphenylbutyl)-l,3-dimethoxypropane, 2-(4- methylcy clohexyl)-2-(3 , 3 -diphenylpropyl)- 1 , 3 -dimethoxypropane, 2-(4-methylcyclohexyl)-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 clohexyl)-2-(3, 3 -dimethylbutyl)- 1,3-dimethoxypropane, 2-(4-methylcyclohexyl)-2-(3-methylpentyl)-l,3-dimethoxypropane, 2-(4- methylcyclohexyl)-2-(3-ethylpentyl)- 1,3-dimethoxypropane. 2-(4-methylcyclohexyl)-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)-l,3-dimethoxypropane, 2-(3- methylcyclohexyl)-2-(cyclopentylethyl)- 1,3 -dimethoxypropane, 2-(4-methylcyclohexyl)-2-(phenethyl)- 1 , 3 -dimethoxypropane, 2-(3 -methylcy clohexyl)-2-(2 -trimethyl silylethyl)- 1,3- dimethoxypropane, 2-(3-methylcyclohexyl)-2-(2-triisopropylsilylethyl)-l,3-dimethoxypropane, 2- (4-methylcy cl ohexyl)-2-(2 -triphenylsilylethyl)- 1,3-dimethoxypropane, 2-(4-methylcyclohexyl)-2- (2-methyldiphenylsilylethyl)-l -ethoxy-3 -methoxy -propane, 2-(4-methylcyclohexyl)-2-(2- dimethylphenyl silylethyl)- 1 -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-l,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)-l,3-dimethoxypropane, 2-cyclohexyl-2-(3,4,4-trimethylpentyl)-l,3- dimethoxypropane, 2-cyclohexyl-2-(3,5-dimethylhexyl)-l,3-dimethoxypropane, 2-cyclohexyl-2-(3- cyclopropylbutyl)-l,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)-l,3-dimethoxypropane, 2-cyclohexyl-2-(3-trifluoromethyl-4,4,4- trifluorobutyl)-l,3-dimethoxypropane, 2-cyclohexyl-2-(3-benzyl-4,4,4-trifluorobutyl)-l,3- dimethoxypropane, 2-cyclohexyl-2-((2,6-dimethyl)cyclohexylethyl)-l,3-dimethoxypropane, 2- cyclohexyl-2-((3,3,5-trimethyl)cyclohexylethyl)-l,3-dimethoxypropane, 2-cyclohexyl-2-(2-(l,7,7- trimethylbicyclo[3.1.1]heptan-6-yl)ethyl)- 1,3 -dimethoxypropane, 2-cyclohexyl-2-(3,3- dibenzylpropyl)-l,3-dimethoxypropane, 2-cyclohexyl-2-(9-fluorenylethyl)-l,3-dimethoxypropane, 2-(4-methylcyclohexyl)-2-isopentyl-l,3-dimethoxypropane, 2-cyclohexyl-2-(3-methylhexyl)-l,3- dimethoxypropane, 2-(4-methylcyclohexyl)-2-(3-methylhexyl)-l,3-dimethoxypropane, 2- cyclohexyl-2-(3,3,3-triphenylpropyl)-l,3-dimethoxypropane, 2-(4-(tert-butyl)cyclohexyl)-2-(3,3,3- trichloropropyl)-l,3-dimethoxypropane, 2-(2-isopropyl-5-methylcyclohexyl)-2-(3,3- difluoropropyl)- 1 , 3 -dimethoxypropane, 2-(3 , 5 -dimethylcy clohexyl)-2-(3 , 3 -dibromopropyl)- 1,3- dimethoxypropane, 2-(2-isopropyl-5-methylcyclohexyl)-2-(3,3-dichloropropyl)-l,3- dimethoxypropane, 2-(2-isopropyl-5-methylcyclohexyl)-2-(3,3-dichloro-3-fluoro-propyl)-l,3- diethoxypropane, 2-(4-(tert-butyl)cy cl ohexyl)-2-(3, 3 -di chi oro-3 -bromo-propyl)- 1,3- dipropoxypropane, 2-(2-i sopropyl-5 -methylcy clohexyl)-2-(3 , 3 -difluoro-3 -bromo-propyl)- 1,3- dibutoxypropane, 2-(2-isopropyl-5-methylcyclohexyl)-2-(3,3-difluoro-3-chloro-propyl)-l,3- dipropoxypropane, 2-(2-isopropyl-5-methylcyclohexyl)-2-(3,3-difluoro-5-methylhexyl)-l,3- diethoxypropane, 2-(2-isopropyl-5-methylcyclohexyl)-2-(3,3-dichloro-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-methylhexyl)- 1,3-di ethoxypropane, 2-(3,5-dimethylcyclohexyl)-2-(3-fluoro-3-isobutyl-5-methylhexyl)-l,3- dipropoxypropane, 2-(2-isopropyl-5-methylcyclohexyl)-2-(3-fluoro-3-isopentyl-6-methylheptyl)- 1,3-di ethoxypropane, 2-(3,5-dimethylcyclohexyl)-2-(3-chloro-3-isopentyl-6-methylheptyl)-l,3- dibutoxypropane, 2-(2-isopropyl-5-methylcyclohexyl)-2-(3-bromo-3-isopentyl-6-methylheptyl)-l,3- dipropoxypropane, 2-(2-isopropyl-5-methylcyclohexyl)-2-(3,3-diphenylbutyl)-l,3-dimethoxypropane, 2-(2-isopropyl-5-methylcyclohexyl)-2-(3,3-diphenylpropyl)-l,3- dimethoxypropane, 2-(2-isopropyl-5-methylcyclohexyl)-2-(3,3,3-triphenylpropyl)-l,3- dimethoxypropane, 2-(2-isopropyl-5-methylcyclohexyl)-2-(3,3,3-tris(4-chlorophenyl)propyl)-l- ethoxy-3 -methoxy -propane, 2-(4-(tert-butyl)cyclohexyl)-2-(3,3-dimethylbutyl)-l,3- dimethoxypropane, 2-(2-isopropyl-5-methylcyclohexyl)-2-(3-methylpentyl)-l,3-dimethoxypropane, 2-(2-isopropyl-5-methylcyclohexyl)-2-(3-ethylpentyl)-l,3-dimethoxypropane, 2-(2-isopropyl-5- methylcyclohexyl)-2-(3,3-diethylpentyl)-l,3-dimethoxypropane, 2-(2-isopropyl-5- methylcyclohexyl)-2-(3-isopropyl-4-methylpentyl)-l,3-dimethoxypropane, 2-(2-isopropyl-5- methylcyclohexyl)-2-(3,3-diisopropyl-4-methylpentyl)-l,3-dimethoxypropane, 2-(2-isopropyl-5- methylcyclohexyl)-2-(cyclohexylethyl)- 1,3 -dimethoxypropane, 2-(3,5-dimethylcyclohexyl)-2-(cy cl opentylethyl)- 1,3 -dimethoxypropane, 2-(2-isopropyl-5-methylcyclohexyl)-2-(phenethyl)-l,3- dimethoxypropane, 2-(3,5-dimethylcyclohexyl)-2-(2-trimethylsilylethyl)-l,3-dimethoxypropane, 2- (3,5-dimethylcyclohexyl)-2-(2-triisopropylsilylethyl)-l,3-dimethoxypropane, 2-(2-isopropyl-5- methylcyclohexyl)-2-(2 -triphenylsilylethyl)- 1,3-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)-l-ethoxy-3-methoxy -propane.

[0016] The ID2 is preferably chosen from diester of dicarboxylic acids or from aromatic or aliphatic diols esterified with monocarboxylic acids.

[0017] Preferred dicarboxylic acids are aliphatic dicarboxylic acids selected from the group consisting of malonates, maleates, citraconates, succinates, glutarates and adipates.

[0018] Preferred esterified diols are those disclosed in W02010 / 078494 and US7,388,061 the specific portion of is hereby enclosed by reference.

[0019] Especially preferred esters of carboxylic acids are selected from malonates, succinates and glutarates.

[0020] Preferred glutarates are those of formula (II)

[0021] wherein the radicals Ri to Rs equal to, or different from, each other, are H or a C1-C20 linear or branched alkyl, alkenyl, cycloalkyl, aryl, arylalkyl or alkylaryl groups, optionally containing heteroatoms, and two or more of said radicals can also be joined to form a cycle, with the provisions that R7 and Rs are both different from hydrogen.

[0022] An interesting class of substituted glutarates is that in which Ri is H and R2 is selected from linear or branched C1-C10 alkyl, cycloalkyl, aryl, arylalkyl and alkylaryl groups. Preferably, R2 is selected from linear or branched C1-C10 alkyls, cycloalkyl, and arylalkyl groups.

[0023] In a preferred embodiment, in the compounds of formula (I) both Ri and R2 are different from hydrogen and are selected from linear or branched C1-C10 alkyl, cycloalkyl, aryl, arylalkyl and alkylaryl groups. More preferably, both Ri and R2 are selected from C2-C5 linear alkyl groups.

[0024] R7 and Rs are preferably primary alkyl, arylalkyl or alkylaryl groups having from 1 to 10 carbon atoms. More preferably they are primary branched alkyl groups having from 1 to 8 carbon atoms. Examples of suitable R7 and Rs groups are methyl, ethyl, n-propyl, n-butyl, isobutyl, neopentyl, 2-ethylhexyl.

[0025] Specific examples of P-monosubstituted glutarate compounds are diisobutyl 3- methylglutarate, diisobutyl 3 -phenylglutarate, diethyl 3 -ethylglutarate, diethyl 3-n-propylglutarate, diethyl 3 -isopropylglutarate, diethyl 3 -isobutylglutarate, diethyl 3 -phenylglutarate, diisobutyl 3- ethylglutarate, diisobutyl 3 -isopropylglutarate, diisobutyl 3 -isobutylglutarate, diethyl 3-(3,3,3- trifluoropropyljglutarate, diethyl 3 -cyclohexylmethyl glutarate, diethyl 3 -tertbutyl glutarate, diisobutyl 2,2'-(3-methylcyclohexane-l,l-diyl)diacetate.

[0026] Specific examples of di or tri substituted glutarates are: diethyl 3, 3 -dimethylglutarate, diisobutyl 3, 3 -dimethylglutarate, diethyl 3-methyl-3-isobutyl glutarate, diethyl 3-methyl-3-t-butyl glutarate, diisobutyl 3-methyl-3-isobutyl glutarate, diethyl 3 -methyl-3 -phenyl glutarate, diethyl 3,3- di-n-propyl glutarate, diisobutyl 3, 3 -di -n-propyl glutarate, diethyl 3, 3 -diisobutyl glutarate, diethyl 3- methyl-3 -butyl glutarate, diethyl 3,3-diphenyl glutarate, diethyl 3 -methyl-3 -ethyl glutarate, diethyl 3,3-diethylglutarate, diethyl 3-methyl-3-isopropyl glutarate, diethyl 3 -phenyl-3 -n-butyl glutarate, diethyl 3 -methyl-3 -t-butyl glutarate, diethyl 3, 3 -diisopropyl glutarate diisobutyl 3 -methyl-3 -phenyl glutarate, diisobutyl 3,3-diisobutyl glutarate, diisobutyl 3 -methyl-3 -butyl glutarate, diisobutyl 3,3- diphenyl glutarate, diisobutyl 3 -methyl-3 -ethyl glutarate, diisobutyl 3,3-diethylglutarate, diisobutyl 3-methyl-3-isopropyl glutarate, diisobutyl 3 -phenyl-3 -n-butyl glutarate, diisobutyl 3-methyl-3-t- butyl glutarate, diisobutyl 3, 3 -diisopropyl glutarate, diethyl 3-ethyl-3 n butyl glutarate, diisobutyl 3- ethyl-3- n-butyl glutarate, diethyl 3 -i -propyl -3 -n-butyl glutarate, diisobutyl 3 -i-propyl-3 -n-butyl glutarate, diethyl 3-(2-methyl-butyl)-3-ethyl glutarate, diisobutyl 3-(2-methyl-butyl)-3-ethyl glutarate, diethyl 3 -n-propyl-3 -phenyl glutarate, diisobutyl 3 -n-propyl-3 -phenyl glutarate diethyl 2-methyl-3 -phenyl glutarate, diethyl 2, 2-dimethyl-3 -phenyl glutarate, diethyl 2-methyl-3,3-diisobutyl glutarate, diethyl 2-ethyl-3-isopropylglutarate, diisobutyl 2-methyl-3 -phenyl glutarate, diisobutyl 2, 4-dimethyl-3 -phenyl glutarate, diisobutyl 2-methyl-3,3-diisobutyl glutarate, diisobutyl 2-ethyl-3- isopropylglutarate. Among them, diethyl 3,3-di-n-propyl glutarate and diisobutyl 3,3-di-n-propyl glutarate are most preferred.

[0027] Preferred succinates are those of formula (III) belowwherein the radicals Ri and R2, equal to or different from each other, are a C1-C20 linear or branched alkyl, alkenyl, cycloalkyl, aryl, arylalkyl or alkylaryl group, optionally containing heteroatoms; the radicals R3 to Re equal to or different from each other, are hydrogen or a C1-C20 linear or branched alkyl, alkenyl, cycloalkyl, aryl, arylalkyl or alkylaryl group, optionally containing heteroatoms, and the radicals R3 to Re which are joined to the same carbon atom of the succinate chain can be linked together to form a cycle.

[0028] Ri and R2 are preferably Ci-Cs alkyl, cycloalkyl, aryl, arylalkyl and alkylaryl groups. Particularly preferred are the compounds in which Ri and R2 are selected from primary alkyls and in particular branched primary alkyls. Examples of suitable Ri and R2 groups are methyl, ethyl, n-propyl, n-butyl, isobutyl, neopentyl, 2-ethylhexyl. Particularly preferred are ethyl, isobutyl, and neopentyl.

[0029] One of the preferred groups of compounds described by the formula (III) is that in which R3 to Rs are hydrogen and Re is a branched alkyl, cycloalkyl, aryl, arylalkyl and alkylaryl radical having from 3 to 10 carbon atoms. Specific examples of suitable monosubstituted succinate compounds are diethyl sec-butyl succinate, diethyl thexyl succinate, diethyl cyclopropylsuccinate, diethyl norbornyl succinate, , diethyl trimethyl silyl succinate, diethyl methoxy succinate, diethyl p- methoxyphenyl succinate, diethyl p-chlorophenylsuccinate diethyl phenyl succinate, diethyl cyclohexylsuccinate, diethyl benzylsuccinate, diethyl cyclohexylmethylsuccinate, diethyl t- butyl succinate, diethyl isobutyl succinate, diethyl isopropyl succinate, diethyl neopentyl succinate, diethyl isopentyl succinate, diethyl (l-trifluoromethylethyl)succinate, diethyl fluorenyl succinate,diisobutyl sec-butyl succinate, diisobutyl thexyl succinate, diisobutyl cyclopropylsuccinate, diisobutyl norbornylsuccinate, diisobutyl perihydrosuccinate, diisobutyl trimethyl silyl succinate, diisobutyl methoxysuccinate, Diisobutyl p-methoxyphenyl succinate, diisobutyl p-chlorophenylsuccinate, diisobutyl cyclohexylsuccinate, diisobutyl benzyl succinate, diisobutyl cyclohexylmethylsuccinate, diisobutyl t-butyl succinate, diisobutyl isobutyl succinate, diisobutyl isopropyl succinate, diisobutyl neopentylsuccinate, diisobutyl isopentyl succinate, diisobutyl (l-trifluoromethylethyl)succinate, diisobutyl phenyl succinate, diisobutyl fluorenyl succinate, dineopentyl sec-butyl succinate, dineopentyl thexyl succinate, dineopentyl cyclopropylsuccinate, dineopentyl norb orny 1 succinate, dineopentyl trimethylsilylsuccinate, dineopentyl methoxy succinate, dineopentyl p- methoxyphenyl succinate, dineopentyl p-chlorophenylsuccinate dineopentyl phenyl succinate, dineopentyl cyclohexylsuccinate, dineopentyl benzylsuccinate, dineopentyl cyclohexylmethylsuccinate, dineopenthyl t-butyl succinate, dineopentyl isobutyl succinate, dineopentyl isopropyl succinate, dineopentyl neopentyl succinate, dineopentyl isopentyl succinate, dineopentyl (l-trifluoromethylethyl)succinate, dineopentyl fluorenylsuccinate.

[0030] Another preferred group of compounds within those of formula (III) is that in which at least two radicals from R3 to Re are different from hydrogen and are selected from C1-C20 linear or branched alkyl, alkenyl, cycloalkyl, aryl, arylalkyl or alkylaryl group, optionally containing heteroatoms. Particularly preferred are the compounds in which the two radicals different from hydrogen are linked to the same carbon atom. Furthermore, also the compounds in which at least two radicals different from hydrogen are linked to different carbon atoms of the succinate chain, that is R3 and Rs or R4 and Re are particularly preferred. Specific examples of suitable disubstituted succinates are: diethyl 2,2-dimethylsuccinate, diethyl 2-ethyl-2-methylsuccinate, diethyl 2-benzyl-2- isopropyl succinate, diethyl 2-cyclohexylmethyl-2-isobutylsuccinate, diethyl 2-cyclopentyl-2-n-butyl succinate, diethyl 2,2-diisobutylsuccinate, diethyl 2-cyclohexyl-2-ethylsuccinate, diethyl 2- isopropyl-2-methylsuccinate, diethyl 2-tetradecyl-2-ethyl succinate, diethyl 2-isobutyl-2- ethyl succinate, diethyl 2-(l-trifluoromethyl-ethyl)-2-methylsuccinate, diethyl 2-isopentyl-2- isobutyl succinate, diethyl 2-phenyl 2-n-butyl succinate, diisobutyl 2,2-dimethylsuccinate, diisobutyl 2-ethyl-2-methylsuccinate, diisobutyl 2-benzyl-2isopropylsuccinate, diisobutyl 2-cyclohexylmethyl- 2-isobutyl succinate, diisobutyl 2-cyclopentyl-2-n-butylsuccinate, diisobutyl 2,2-diisobutylsuccinate, diisobutyl 2-cyclohexyl-2-ethylsuccinate, diisobutyl 2-isopropyl-2-methylsuccinate, diisobutyl 2- tetradecyl-2-ethylsuccinate, diisobutyl 2-isobutyl-2-ethylsuccinate, diisobutyl 2-(l-trifluoromethyl- ethyl)-2-m ethyl succinate, diisobutyl 2-isopentyl-2-isobutylsuccinate, diisobutyl 2-phenyl 2-n-butyl- succinate, dineopentyl 2,2-dimethylsuccinate, dineopentyl 2-ethyl-2 -methyl succinate, dineopentyl 2- Benzyl-2-isopropylsuccinate, dineopentyl 2-cyhexylmethyl-2-isobutylsuccinate, dineopentyl 2-cyclopentyl-2-n-butylsuccinate, dineopentyl 2,2-diisobutyl succinate, dineopentyl 2-cyclohexyl-2- ethyl succinate, dineopentyl 2-isopropyl-2-methylsuccinate, dineopentyl 2-tetradecyl-2- ethyl succinate, dineopentyl 2-isobutyl-2-ethyl succinate, dineopentyl 2-(l-trifluoromethyl-ethyl)-2- methyl succinate, dineopentyl 2-isopentyl-2-isobutylsuccinate, dineopentyl 2-phenyl 2-n- butylsuccinate.

[0031] Furthermore, also the compounds in which at least two radicals different from hydrogen are linked to different carbon atoms, that is R3 and Rs or R4 and Re are particularly preferred. Specific examples of suitable compounds are diethyl 2,3bis(trimethylsilyl)succinate, diethyl 2,2-secbutyl-3- methyl succinate, diethyl 2-(3,3,3,trifluoropropyl)-3-methylsuccinate, diethyl 2,3 bis(2-ethyl- butyl)succinate, diethyl 2,3-diethyl-2-isopropylsuccinate, diethyl 2,3-diisopropyl-2-methylsuccinate, diethyl 2,3-dicyclohexyl-2-methyl diethyl 2,3-dibenzylsuccinate, diethyl 2,3-diisopropylsuccinate, diethyl 2,3-bis(cyclohexylmethyl)succinate, diethyl 2,3-di-t-butylsuccinate, diethyl 2,3- diisobutyl succinate, diethyl 2, 3 -dineopentyl succinate, diethyl 2,3-diisopentylsuccinate, diethyl 2,3- (l-trifluoromethyl-ethyl)succinate, diethyl 2,3-tetradecylsuccinate, diethyl 2,3-fluorenylsuccinate, diethyl 2-isopropyl-3-isobutylsuccinate, diethyl 2-terbutyl-3 -isopropyl succinate, diethyl 2-ipropyl-3- cyclohexylsuccinate, diethyl 2-isopentyl-3-cyclohexylsuccinate, diethyl 2 -tetradecyl-3 - cyclohexylmethylsuccinate, diethyl 2-cyclohexyl-3-cyclopentylsuccinate. diisobutyl 2,3-diethyll-2- isopropyl succinate, diisobutyl 2,3-diisopropyl-2-methylsuccinate, diisobutyl 2,3-dicyclohexyl-2- methyl succinate, diisobutyl 2,3-dibenzylsuccinate, diisobutyl 2,3-diisopropylsuccinate, diisobutyl 2,3-bis(cyclohexylmethyl)succinate, diisobutyl 2,3-di-t-butylsuccinate, diisobutyl 2,3- diisobutylsuccinate, diisobutyl 2, 3 -dineopentyl succinate, diisobutyl 2,3-diisopentylsuccinate, diisobutyl 2,3-(l-trifhroromethyl-ethyl)succinate, diisobutyl 2,3-tetradecylsuccinate, diisobutyl 2,3- fluorenylsuccinate, diisobutyl 2-ipropyl-3-ibutylsuccinate, diisobutyl 2-terbutyl-3-ipropylsuccinate, diisobutyl 2-ipropyl-3-cyclohexylsuccinate, diisobutyl 2-isopentyl-3-cyclohexylsuccinate, diisobutyl 2-tetradecyl-3-cyclohexylmethylsuccinate, diisobutyl 2-cyclohexyl-3-cyclopentylsuccinate, dineopentyl 2,3bis(trimethylsilyl)succinate, dineopentyl 2,2-secbutyl-3-methylsuccinate, dineopentyl 2-(3,3,3,trifluoropropyl)-3-methylsuccinate, dineopentyl 2,3 bis(2-ethyl-butyl)succinate, dineopentyl 2,3-diethyl-2-isopropylsuccinate, dineopentyl 2,3-diisopropyl-2-methylsuccinate, dineopentyl 2,3-dicyclohexyl-2-methyl, dineopentyl 2,3-dibenzylsuccinate, dineopentyl 2,3- diisopropylsuccinate, dineopentyl 2,3-bis(cyclohexylmethyl)succinate, dineopentyl 2,3-di-t- butylsuccinate, dineopentyl 2,3-diisobutylsuccinate, dineopentyl 2, 3 -dineopentyl succinate, dineopentyl 2,3-diisopentylsuccinate, dineopentyl 2,3-(l-trifluoromethyl-ethyl)succinate, dineopentyl 2,3-tetradecylsuccinate, dineopentyl 2,3-fluorenylsuccinate, dineopentyl 2-ipropyl-3- ibutyl succinate, dineopentyl 2-terbutyl-3-isopropylsuccinate, dineopentyl 2-isopropyl-3-cyclohexylsuccinate, dineopentyl 2-isopentyl-3-cyclohexylsuccinate, dineopentyl 2 -tetradecyl-3 - cyclohexylmethyl succinate, dineopentyl 2-cyclohexyl-3-cyclopentylsuccinate.

[0032] Another preferred subclass of succinates can be selected from those of formula (Illa) belowin which the radicals Ri and R2, equal to, or different from, each other are a C1-C20 linear or branched alkyl, alkenyl, cycloalkyl, aryl, arylalkyl or alkylaryl group, optionally containing heteroatoms; and the radicals R3 and R4 equal to, or different from, each other, are C1-C20 alkyl, C3- C20 cycloalkyl, C5-C20 aryl, arylalkyl or alkylaryl group with the proviso that at least one of them is a branched alkyl; said compounds being, with respect to the two asymmetric carbon atoms identified in the structure of formula (Illa), stereoisomers of the type (S,R) or (R,S).

[0033] Ri and R2 are preferably Ci-Cs alkyl, cycloalkyl, aryl, arylalkyl and alkylaryl groups. Particularly preferred are the compounds in which Ri and R2 are selected from primary alkyls and in particular branched primary alkyls. Examples of suitable Ri and R2 groups are methyl, ethyl, n-propyl, n-butyl, isobutyl, neopentyl, 2-ethylhexyl. Particularly preferred are ethyl, isobutyl, and neopentyl.

[0034] Particularly preferred are the compounds in which the R3 and / or R4 radicals are secondary alkyls like isopropyl, sec-butyl, 2-pentyl, 3-pentyl or cycloakyls like cyclohexyl, cyclopentyl and cyclohexylmethyl.

[0035] Examples of the above-mentioned compounds are the (S,R) (S,R) forms pure or in mixture, optionally in racemic form, of diethyl 2,3-bis(trimethylsilyl)succinate, diethyl 2,3-bis(2- ethylbutyl)succinate, diethyl 2,3-dibenzylsuccinate, diethyl 2,3-diisopropylsuccinate, diisobutyl 2,3- diisopropyl succinate, diethyl 2,3-bis(cyclohexylmethyl)succinate, diethyl 2, 3 -diisobutyl succinate, diethyl 2,3-dineopentylsuccinate, diethyl 2,3-dicyclopentylsuccinate, diethyl 2,3- dicyclohexylsuccinate

[0036] Preferred mal onates are those of formula (IV):where Ri is H or a C1-C20 linear or branched alkyl, alkenyl, cycloalkyl, aryl, arylalkyl or alkylaryl group, R2 is a C1-C20 linear or branched alkyl, alkenyl, cycloalkyl, aryl, arylalkyl or alkylaryl group, R3 and R4, equal to, or different from, each other, are C1-C20 linear or branched alkyl groups or C3-C20 cycloalkyl groups.

[0037] Preferably, R3 and R4 are primary, linear or branched C1-C20 alkyl groups, more preferably they are primary branched C4-C20 alkyl groups such as isobutyl or neopentyl groups.

[0038] R2 is preferably, in particular when Ri is H, a linear or branched C3-C20 alkyl, cycloalkyl, or arylalkyl group; more preferably R2 is a C3-C20 secondary alkyl, cycloalkyl, or arylalkyl group.

[0039] Specific examples of preferred monosubstituted malonate compounds are: dineopentyl 2- isopropylmalonate, diisobutyl 2-isopropylmalonate, di-n-butyl 2-isopropylmalonate, diethyl 2- dodecylmalonate, diethyl 2-t-butylmalonate, diethyl 2-(2-pentyl)malonate, diethyl 2- cyclohexylmalonate, dineopentyl 2-t-butylmalonate, dineopentyl 2-isobutylmal onate, diethyl 2- cyclohexylmethylmalonate, dimethyl 2-cyclohexylmethylmalonate.

[0040] Specific examples of preferred disubstituted malonates compounds are: diethyl 2,2- dibenzylmalonate, diethyl 2-isobutyl-2-cyclohexylmalonate, dimethyl 2-n-butyl-2-isobutylmalonate, diethyl 2-n-butyl-2-isobutylmalonate, diethyl 2-isopropyl-2-n-butylmalonate, diethyl 2-methyl-2- isopropylmalonate, diethyl 2-isopropyl-2-isobutylmalonate, diethyl 2-methyl-2-isobutylmalonate, diethyl 2-isobutyl-2-benzylmalonate, diethyl 2,2-diisobutyl malonate, diethyl 2-isopentyl-2- cyclohexylmalonate.

[0041] Preferably the molar ratio ID2 / ID1 ranges from 1.1 to 2.0, more preferably from 1.1 to 1.8 and especially from 1.1 to 1.6 and in a particularly preferred embodiment from 1.3 to 1.6.

[0042] Preferably, the molar ratio between the sum of ID1 and ID2 (ID1+ID2) and the Ti atoms in the final solid catalyst component ranges from ranges from 0.65: 1 to 1.5: 1 and more preferably from 0.70: 1 to 1.40: 1 and especially from 0.75: 1 to 1.30: 1.

[0043] Preferably, the molar ratio between the Mg atoms and the ID1 in the final solid catalyst component is higher than 20.0, preferably higher than 25.0 and more preferably higher than 30.0.

[0044] Preferably, the ID2 / Ti molar ratio ranges from 0.20: 1 to 0.90: 1 more preferably from 0.30: 1 to 0.80: 1 especially from 0.40: 1 to 0.75: 1.

[0045] 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 cm3 / g. More preferably, the porosity is higher than 0.30 cm3 / g and especially higher than 0.40 cm3 / g.

[0046] Preferably, the said catalyst component has an average particle size ranging from 20 to 150pm and more preferably from 40 to 100 pm.

[0047] 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(OR5)n-yXycan be used, where n is the valence of titanium, y is a number between 1 and n-1, X is halogen and R5is a hydrocarbon radical having from 1 to 10 carbon atoms.

[0048] 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(0R5)m-yXy, 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 MgC12*pR6OH, where p is a number between 0.1 and 6, preferably from 2 to 3.5, and R6is 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.

[0049] 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 ID2 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 ID2 is fed in amounts such as to meet the desired molar ratio in the final catalyst. In an embodiment the Mg / ID2 molar ratio may range from 5: 1 to 50: 1, preferably 10: 1 to 45: 1 and more preferably from 15: 1 to 40:1. The temperature is then graduallyraised 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. Preferably, ID1 is added at this stage. The ID1 is preferably fed in amounts such that the Mg / IDl molar ratio may range from 10: 1 to 40: 1, preferably 12: 1 to 35:1, more preferably from 15: 1 to 30: 1. 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 TiCU 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.

[0050] 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 I lls of the periodic table of elements (TUPAC version).

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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 AlEt2Cl and AhEtsCh, possibly in mixture with the above cited trialkylaluminum compounds.

[0056] 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.

[0057] Another class of preferred external donor compounds is that of silicon compounds of formula (R7)a(R8)bSi(OR9)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; R7, R8, and R9, 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 R7and R8is selected from branched alkyl, cycloalkyl or aryl groups with 3-10 carbon atoms optionally containing heteroatoms and R9is a Ci-Cio alkyl group, in particular methyl. Examples of such preferred silicon compounds are methylcyclohexyldimethoxy silane (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, R8is a branched alkyl or cycloalkyl group, optionally containing heteroatoms, and R9is methyl. Examples of such preferred silicon compounds are cyclohexyltrimethoxysilane, t-butyltrimethoxysilane and thexyltrimethoxysilane.

[0058] 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.

[0059] The catalyst of the present disclosure provide a highly stereoregular polypropylene even when an external donor is absent. This is evidenced by the amount of xylene insoluble fraction which does not fall below 96.5%wt without external donor which is a value perfectly fitting for BOPP grades. It is possible to modulate stereocontrol by the use of external donor and in this case values approaching 99.0% of xylene insolubility can be obtained. It has to be noted that the above mentioned stereoregular polypropylene is obtained in very high yields and that the performances of the catalyst components of the present disclosure are better than those based on different diether / diester mixtures and at the same time are able to give performances that would be reachable only with higher amounts of ID1 only.

[0060] 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 hydrocarbon radical 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).

[0061] 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.

[0062] 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 pre-polymerized 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.

[0063] 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.

[0064] 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.

[0065] The polymerization is generally carried out at temperature ranging from 20 to 120°C, preferably from 40 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.

[0066] The preferred alpha-olefins to be (co)polymerized are ethylene, propylene, 1 -butene, 4- m ethyl- 1 -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 propyl ene / 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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. .

[0071] The following examples are given to illustrate and not to limit the invention itself.CHARACTERIZATIONDetermination of porosity.

[0072] 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 (cm3 / 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

[0073] 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.The content of electron donor was determined via gas-chromatography.Determination of Melt flow rate (MFR).

[0074] The melt flow rate MIL of the polymer was determined according to ISO 1133 (230° C, 2.16 Kg).Determination of comonomer.

[0075] The content of comonomer (ethylene) has been determined via NMR spectroscopy.Determination of TmDetermined 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.)

[0076] On the xylene soluble fraction, the intrinsic 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

[0077] Flexural Modulus is measured according to ISO 178 and ISO 1873-2Determination of Tensile Modulus

[0078] Tensile Modulus is measured according to ISO 527 and ISO 1873-2Determination of Charpy

[0079] Charpy impact test according to ISO 179-leA, and ISO 1873-2Determination of13C NMR spectra of propylene / ethylene copolymers

[0080] The13C NMR spectra of the heterophasic copolymers and of their XI and XS fractions were acquired on a Bruker AV-600 spectrometer equipped with cry oprobe, 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 by13C 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 andCPD to remove 1H-13C coupling. 512 transients were stored in 32K data points using a spectral window of 9000 Hz.

[0081] 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 ethylene-propylene copolymers prepared with 5-titanium trichloride- diethylaluminum 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 T55 / SPEP = 100 Spp / S PEE = 100 Sps / S EEE = 100 (0.25 Sy5+ 0.5 S5s) / SS = Tpp + Tpg + Tss + Spp + Sps + 0.25 SYs + 0.5 Sss

[0082] The molar percentage of ethylene content was evaluated using the following equation:E% mol = 100 x [PEP+PEE+EEE]

[0083] 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.EXAMPLESGeneral procedure for the preparation of MgCh*pEtOH adducts.

[0084] 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 donorsSynthesis of 2-cyclohexyl-2-isopentyl-l,3-dimethoxypropaneStep 1 : synthesis of diethyl 2-cyclohexylmalonate

[0085] 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, diethylmalonate (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% NaHCOs, then evaporated, thus leading to 26 g of diethyl 2-cyclohexylmalonate as a light yellow oil,purity 99% (GC), yield 27%.1HNMR (5, 400 MHz, CDC13): 4.2 (q, 4H, OCH ), 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

[0086] 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%.1HNMR (5, 400 MHz, CDCI3): 4.1 (q, 4H, CH2), 1.7 (m, 3H, CH cyclohexyl + a-C / A isopentyl), 1.6-1.3 (m, 8H, cyclohexyl), 1.2 (m, 7H, OCH2C / / 3 + -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

[0087] 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%.1HNMR (5, 400 MHz, CDCI3): 4.9-4.6 (dd, 4H, CH2), 2.2 (s, 2H, OH), 1.9-1.1 (m, 16H, cyclohexyl + isopentyl), 0.9 (d, 6H, (CH3)2isopentyl).Step 4: synthesis of 2-cyclohexyl-2-isopentyl-l ,3-dimethoxypropaneTo a 500 mL round bottom flask equipped with mechanical stirrer, thermometer and condenser is added tetrahydrofuran (70 mL), 2-cyclohexyl-2-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%.1HNMR (5, 400 MHz, CDCI3): 3.2 (s, 6H, CH3O), 3.1 (s, 4H, OCH2), 1.8-1.0 (m, 16H, cyclohexyl + isopentyl), 0.8 (d, 6H, (CH?)2 isopentyl).Preparation of solid catalyst component - general procedure.

[0088] Into a 1000 mL four-necked round flask, purged with nitrogen, 500 mL of TiCh were introduced at 0°C. While stirring, 25 grams of the microspheroidal MgC12-2.1EtOH adduct (prepared as described above) were added. Then, an amount of BiCh to have a molar ratio Mg / BiCh of 60 was charged at -3 °C and thereafter an amount of ID2 such as to have the Mg / Donor ratio reported in Table 1 was charged at 40°C.The temperature was raised to 100°C and kept at this value for 60 minutes. After, the stirring was stopped, the liquid siphoned off and the treatment with TiCh was repeated at 120°C for 30 minutes while charging at the beginning the amount of ID1 reported in table 1. After siphoning, a further treatment with TiCh at 120° for 15 minutes was carried out.After sedimentation and siphoning the solid was washed with anhydrous heptane (6 x 100 ml) at decreasing temperatures from 90°C to RT 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

[0089] 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: 14 ml of anhydrous hexane containing 0.6 g of Al Eh, 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 the amount of hydrogen indicated in Table 2 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.

[0090] Examples 1-7 and comparative example 8. Polymerization of propylene.

[0091] Catalysts of inventive examples 1-4 and comparative example 5 were prepared in accordance with the general procedure described above, except that for example 4 BiCh was not used and that in example 7 the first treatment with TiCh was carried out at 120°C. The donor type and their amounts are described in Table 1. The results of the bulk polymerization of propylene is reported in Table 2.Table 1.Dl= 2-cyclohexyl-2-isopentyl-l,3-dimethoxypropaneDEDIPS= diethyl 2, 3 -diisopropyl succinateBMMF= 9,9-bis(methoxymethyl)fluoreneDMCD = diisobutyl 2, 2'-(3 -methylcyclohexane- l,l-diyl)diacetateTable 2TEAL / Ext. Donor molar ratio 20

Claims

CLAIMSWhat is claimed is:

1. 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 two electron donor compounds one of which (ID1) being selected from 1,3-diethers of formula (I)in which R1and R2are, independently, C1-C5 alkyl groups, X is Si or C, R3and R4groups, independently, are selected from hydrogen, C1-C20 hydrocarbon groups and halogens with the proviso that at least two R3are not hydrogen and the other (ID2) being selected from organic compounds bearing two ester groups, said solid catalyst component being further characterized by the fact that the molar ratio between ID2 and ID1 (ID2 / ID1) is equal to, or higher than, 1.0.

2. The solid catalyst component according to claim 1 in which R1and R2are the same and are selected from C1-C4 linear or branched alkyl groups and more preferably from methyl groups.

3. The solid catalyst component according to claim 1 in which all R4groups are hydrogen.

4. The solid catalyst component according to any of the preceding claims in which when R3is a hydrocarbon group it is selected from C1-C4 linear or branched alkyl groups and groups linked together to form a C6 saturated ring optionally substituted with C1-C4 linear alkyl groups.

5. The solid catalyst component according to any of the preceding claims 1-4 in which X is carbon.

6. The solid catalyst component according to any of the preceding claims in which the ID2 is selected from esters of aliphatic dicarboxylic acids selected from the group consisting of malonates, maleates, citraconates, succinates, glutarates and adipates.

7. The solid catalyst component according to claim 6 in which succinates are those of formula (III)wherein the radicals Ri and R2, equal to or different from each other, are a C1-C20 linear or branched alkyl, alkenyl, cycloalkyl, aryl, arylalkyl or alkylaryl group, optionally containing heteroatoms; the radicals R3 to Re equal to or different from each other, are hydrogen or a C1-C20 linear or branched alkyl, alkenyl, cycloalkyl, aryl, arylalkyl or alkylaryl group, optionally containing heteroatoms, and the radicals R3 to Re which are joined to the same carbon atom of the succinate chain can be linked together to form a cycle.

8. The solid catalyst component according to any of the preceding claims in which the molar ratio ID2 / ID1 ranges from 1.1 to 2.0, more preferably from 1.1 to 1.8, especially from 1.1 to 1.6 and in a particularly preferred embodiment from 1.3 to 1.6.

9. The solid catalyst component according to any of the preceding claims in which the molar ratio between the Mg atoms and the ID1 in the final solid catalyst component is higher than 20.0, preferably higher than 25.0 and more preferably higher than 30.0.

10. The solid catalyst component according to any of the preceding claims in which the ID2 / Ti molar ratio ranges from 0.20: 1 to 0.90: 1 more preferably from 0.30: 1 to 0.80: 1 especially from 0.40:1 to 0.75: 1.

11. The solid catalyst component according to any of the preceding claims in which the molar ratio between the sum of ID1 and ID2 (ID1+ID2) and the Ti atoms in the final solid catalyst component ranges from ranges from 0.65: 1 to 1.5: 1 and more preferably from 0.70: 1 to 1.40: 1 and especially from 0.75: 1 to 1.30: 1.

12. The solid catalyst component according to any of the preceding claims comprising additional metal compounds which do not contain metal-carbon bonds and include elements selected from Cu, Zn, and Bi.

13. The solid catalyst component according to claim 12 in which the metal compound is selected from BiCh.Bi carbonates and Bi carboxylates.

14. Catalyst for the polymerization of olefins CH2=CHR, in which R is hydrogen or a hydrocarbonradical with 1-12 carbon atoms, comprising the product of the reaction between:(i) the solid catalyst component according to any of the preceding claims and(ii) an alkylaluminum compound and optionally(iii) an external donor compound.

15. 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 as defined in claim 14.

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