The present invention relates to heterophasic polypropylene compositions comprising a propylene homo- or copolymer forming a crystalline fraction as a matrix and an amorphous propylene ethylene elastomer as a soluble fraction dispersed in said matrix. The heterophasic polypropylene compositions further comprise an elastomeric ethylene/alpha-olefin random copolymer. The heterophasic polypropylene compositions have a well-balanced relation between stiffness and impact strength, low volatile and semi-volatile emissions and good processability.

The present invention relates to heterophasic polypropylene compositions comprising a propylene homo- or copolymer forming a crystalline fraction as a matrix and an amorphous propylene ethylene elastomer as a soluble fraction dispersed in said matrix. The heterophasic polypropylene compositions further comprise an elastomeric ethylene/alpha-olefin random copolymer. The heterophasic polypropylene compositions have a well-balanced relation between stiffness and impact strength, low volatile and semi-volatile emissions and good processability.

A metallocene compound having a structure shown by formula (I). A functional group connected to a bridging atom of the metallocene compound is an amine-substituted group and/or a metallocene-substituted group and/or a substituted metallocene group. A metallocene catalyst containing the metallocene compound has high catalytic activity, and can synthesize metallocene polypropylene having high isotacticity.

R.sup.IR.sup.IIZ(Cp.sup.III).sub.n(E).sub.2-nML.sup.IVL.sup.V   (I)

A metallocene compound having a structure shown by formula (I). A functional group connected to a bridging atom of the metallocene compound is an amine-substituted group and/or a metallocene-substituted group and/or a substituted metallocene group. A metallocene catalyst containing the metallocene compound has high catalytic activity, and can synthesize metallocene polypropylene having high isotacticity.

R.sup.IR.sup.IIZ(Cp.sup.III).sub.n(E).sub.2-nML.sup.IVL.sup.V   (I)

A catalyst compound and process for olefin polymerization. The catalyst can be represented by Formula (I):

##STR00001##

wherein: M is a transition metal selected from group 3, 4, or 5 of the Periodic Table of Elements; L is a linking group selected from any one or more difunctional C.sub.1-C.sub.20 hydrocarbyl, aryl or substituted aryl groups; T is an optional bridging group; each X is a univalent anionic ligand, or two Xs are joined and bound to the metal atom to form a metallocycle ring, or two Xs are joined to form a chelating ligand, a diene ligand, or an alkylidene ligand; R.sup.1 and R.sup.2 are each independently a hydrogen atom or substituted or unsubstituted C.sub.1 to C.sub.20 hydrocarbyl group; R.sup.3, R.sup.5, R.sup.6 and R.sup.7 are each independently a hydrogen atom or a substituted or unsubstituted C.sub.1 to C.sub.20 hydrocarbyl group, and, optionally, any two of R.sup.5, R.sup.6, and R.sup.7 can be joined to form a cyclic structure; R.sup.4 is a substituted or unsubstituted aryl group; and R.sup.8, R.sup.9, R.sup.10, and R.sup.11 are each independently a substituted or unsubstituted C.sub.1 to C.sub.6 hydrocarbyl group and, optionally, R.sup.9 and R.sup.10 are joined to form a cyclic structure.

A catalyst compound and process for olefin polymerization. The catalyst can be represented by Formula (I):

##STR00001##

wherein: M is a transition metal selected from group 3, 4, or 5 of the Periodic Table of Elements; L is a linking group selected from any one or more difunctional C.sub.1-C.sub.20 hydrocarbyl, aryl or substituted aryl groups; T is an optional bridging group; each X is a univalent anionic ligand, or two Xs are joined and bound to the metal atom to form a metallocycle ring, or two Xs are joined to form a chelating ligand, a diene ligand, or an alkylidene ligand; R.sup.1 and R.sup.2 are each independently a hydrogen atom or substituted or unsubstituted C.sub.1 to C.sub.20 hydrocarbyl group; R.sup.3, R.sup.5, R.sup.6 and R.sup.7 are each independently a hydrogen atom or a substituted or unsubstituted C.sub.1 to C.sub.20 hydrocarbyl group, and, optionally, any two of R.sup.5, R.sup.6, and R.sup.7 can be joined to form a cyclic structure; R.sup.4 is a substituted or unsubstituted aryl group; and R.sup.8, R.sup.9, R.sup.10, and R.sup.11 are each independently a substituted or unsubstituted C.sub.1 to C.sub.6 hydrocarbyl group and, optionally, R.sup.9 and R.sup.10 are joined to form a cyclic structure.

New polypropylene composition which combines low sealing initiation temperature (SIT), high hot-tack and good mechanical properties, like high dart drop strength (DDI), and its use especially for film applications.

New polypropylene composition which combines low sealing initiation temperature (SIT), high hot-tack and good mechanical properties, like high dart drop strength (DDI), and its use especially for film applications.

Provided are methods for producing bimodal polyolefins comprising the steps of contacting α-olefin monomers with a catalyst in slurry polymerization conditions in the presence of zero to minimum hydrogen to produce a high molecular weight polyolefin and contacting additional α-olefin monomers in gas phase polymerization conditions and the high molecular weight polyolefin and the catalyst to produce bimodal polyolefin having high stiffness and broad molecular weight distribution. An additional step of polymerizing the bimodal polyolefin with a comonomer in a second gas phase can provide a bimodal impact copolymer having high stiffness and broad molecular weight distribution. Among the advantages of the present methods, bimodal polyolefins can be produced in a continuous process between a slurry polymerization reactor and a gas phase polymerization reactor without a venting step in between and with minimal hydrogen in the slurry polymerization reactor.

Provided are methods for producing bimodal polyolefins comprising the steps of contacting α-olefin monomers with a catalyst in slurry polymerization conditions in the presence of zero to minimum hydrogen to produce a high molecular weight polyolefin and contacting additional α-olefin monomers in gas phase polymerization conditions and the high molecular weight polyolefin and the catalyst to produce bimodal polyolefin having high stiffness and broad molecular weight distribution. An additional step of polymerizing the bimodal polyolefin with a comonomer in a second gas phase can provide a bimodal impact copolymer having high stiffness and broad molecular weight distribution. Among the advantages of the present methods, bimodal polyolefins can be produced in a continuous process between a slurry polymerization reactor and a gas phase polymerization reactor without a venting step in between and with minimal hydrogen in the slurry polymerization reactor.