A method for producing a solid catalyst for olefin (co)polymerization includes bringing into contact with each other a magnesium compound, a tetravalent titanium halide compound, an organic compound represented the following general formula (1)
R.sup.1.sub.k(C.sub.6H.sub.4-k)(COOR.sup.2)(COOR.sup.3)(1) and
an organic compound represented the following general formula (2)
R.sup.4R.sup.5CC (COOR.sup.6)(COOR.sup.7)(2)
wherein R.sup.1 is a halogen atom or an alkyl group, R.sup.2 and R.sup.3 are a linear alkyl group, R.sup.4 and R.sup.5 are independently an atom or group selected from a hydrogen atom, halogen, a linear alkyl group, a branched alkyl group a vinyl group, a linear or branched alkenyl group, a cycloalkenyl group, an aromatic hydrocarbon group, and R.sup.6 and R.sup.7 are independently a linear alkyl group, a branched alkyl group, a vinyl group, a linear or branched alkenyl group a cycloalkyl group, a cycloalkenyl group, or an aromatic hydrocarbon group.

A catalyst for the homopolymerization or copolymerization of CH.sub.2CHR olefins, made from or containing the product obtained by contacting: (i) a solid catalyst component made from or containing Ti, Mg, Cl, and an internal electron donor compound, wherein the solid catalyst component contains from about 0.1 to about 50 wt % of Bi, based upon the total weight of the solid catalyst component; (ii) an alkyl aluminum compound and, (iii) an external electron donor compound having the formula:

(R1)aSi(OR2)b

wherein R.sup.1 and R.sup.2 are independently selected from the group consisting of alkyl radicals with 1-8 carbon atoms and a is 0 or 1 and a+b=4.

A catalyst for the homopolymerization or copolymerization of CH.sub.2CHR olefins, made from or containing the product obtained by contacting: (i) a solid catalyst component made from or containing Ti, Mg, Cl, and an internal electron donor compound, wherein the solid catalyst component contains from about 0.1 to about 50 wt % of Bi, based upon the total weight of the solid catalyst component; (ii) an alkyl aluminum compound and, (iii) an external electron donor compound having the formula:

(R1)aSi(OR2)b

wherein R.sup.1 and R.sup.2 are independently selected from the group consisting of alkyl radicals with 1-8 carbon atoms and a is 0 or 1 and a+b=4.

The present invention relates to an olefin polymerization process, wherein propylene and a C4 to C10 -olefin monomer, preferably 1-butene- and optionally ethylene are reacted in the presence of a Ziegler-Natta catalyst so as to obtain a polypropylene, wherein the polypropylene comprises C4 to C10 -olefin, preferably 1-butene-derived comonomer units in an amount of from 0,5 to 15 wt % and ethylene-derived comonomer units in an amount of 0 to 3 wt %, and wherein the Ziegler-Natta catalyst comprises i) an external donor of the formula (I): (R.sup.3).sub.z(R.sup.2O).sub.ySi(R.sup.1).sub.x, and ii) a solid catalyst component being free of external carrier material.

The present invention relates to an olefin polymerization process, wherein propylene and a C4 to C10 -olefin monomer, preferably 1-butene- and optionally ethylene are reacted in the presence of a Ziegler-Natta catalyst so as to obtain a polypropylene, wherein the polypropylene comprises C4 to C10 -olefin, preferably 1-butene-derived comonomer units in an amount of from 0,5 to 15 wt % and ethylene-derived comonomer units in an amount of 0 to 3 wt %, and wherein the Ziegler-Natta catalyst comprises i) an external donor of the formula (I): (R.sup.3).sub.z(R.sup.2O).sub.ySi(R.sup.1).sub.x, and ii) a solid catalyst component being free of external carrier material.

A blown film made from or containing a polyolefin composition (I) made from or containing: A) from about 40 to about 75 wt. %, based upon the total weight of the polyolefin composition, of a polyethylene having a density of about 0.920 to about 0.940 g/cm.sup.3 and a fraction soluble in xylene (XS.sub.A) of less than about 10% wt. %; and B) from about 25 to about 60 wt. %, based upon the total weight of the polyolefin composition, of a copolymer of ethylene with one or more comonomers selected from -olefins having formula HC.sub.2CHR.sup.I, where R.sup.I is an alkyl radical, linear or branched, having from 1 to 8 carbon atoms, made from or containing from about 50 to about 70 wt. % of ethylene and having a fraction soluble in xylene (XS.sub.B) of at least 50 wt. %.

A blown film made from or containing a polyolefin composition (I) made from or containing: A) from about 40 to about 75 wt. %, based upon the total weight of the polyolefin composition, of a polyethylene having a density of about 0.920 to about 0.940 g/cm.sup.3 and a fraction soluble in xylene (XS.sub.A) of less than about 10% wt. %; and B) from about 25 to about 60 wt. %, based upon the total weight of the polyolefin composition, of a copolymer of ethylene with one or more comonomers selected from -olefins having formula HC.sub.2CHR.sup.I, where R.sup.I is an alkyl radical, linear or branched, having from 1 to 8 carbon atoms, made from or containing from about 50 to about 70 wt. % of ethylene and having a fraction soluble in xylene (XS.sub.B) of at least 50 wt. %.

A method for producing a solid catalyst for olefin (co)polymerization includes bringing into contact with each other a magnesium compound, a tetravalent titanium halide compound, an organic compound represented the following general formula (1)

R.sup.1.sub.k(C.sub.6H.sub.4-k)(COOR.sup.2)(COOR.sup.3) (1) and

an organic compound represented the following general formula (2)

R.sup.4R.sup.5CC (COOR.sup.6)(COOR.sup.7) (2)

wherein R.sup.1 is a halogen atom or an alkyl group, R.sup.2 and R.sup.3 are a linear alkyl group, R.sup.4 and R.sup.5 are independently an atom or group selected from a hydrogen atom, halogen, a linear alkyl group, a branched alkyl group a vinyl group, a linear or branched alkenyl group, a cycloalkenyl group, an aromatic hydrocarbon group, and R.sup.6 and R.sup.7 are independently a linear alkyl group, a branched alkyl group, a vinyl group, a linear or branched alkenyl group a cycloalkyl group, a cycloalkenyl group, or an aromatic hydrocarbon group.

A method for producing a solid catalyst for olefin (co)polymerization includes bringing into contact with each other a magnesium compound, a tetravalent titanium halide compound, an organic compound represented the following general formula (1)

R.sup.1.sub.k(C.sub.6H.sub.4-k)(COOR.sup.2)(COOR.sup.3) (1) and

an organic compound represented the following general formula (2)

R.sup.4R.sup.5CC (COOR.sup.6)(COOR.sup.7) (2)

wherein R.sup.1 is a halogen atom or an alkyl group, R.sup.2 and R.sup.3 are a linear alkyl group, R.sup.4 and R.sup.5 are independently an atom or group selected from a hydrogen atom, halogen, a linear alkyl group, a branched alkyl group a vinyl group, a linear or branched alkenyl group, a cycloalkenyl group, an aromatic hydrocarbon group, and R.sup.6 and R.sup.7 are independently a linear alkyl group, a branched alkyl group, a vinyl group, a linear or branched alkenyl group a cycloalkyl group, a cycloalkenyl group, or an aromatic hydrocarbon group.

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