Catalyst system, process for olefin polymerization, and polymer compositions produced therefrom

A process for the production of one or more copolymer compositions comprising contacting propylene and one or more comonomers with a catalyst system under polymerization conditions including conducting the polymerization in a homogeneous solution at a temperature of from about 80° C. to about 200° C. and a monomer conversion of from 5 to 90%, where:

• a. the catalyst system comprises a transition metal compound and an activator, the activator having the formula:
• [RnAH][Y]−,
• where the R groups may be identical or different and are a C1 to C3 alkyl group;
• A is nitrogen;
• n is 3;
• and [Y]− is a non-coordinating anion represented by [B(R4)4]−, with R4 being an aryl group or a substituted aryl group, of which the one or more substituents are identical or different and are selected from the group consisting of alkyl, aryl, a halogen atom, halogenated aryl, and haloalkylaryl groups;
• and
• wherein the transition metal compound is a dialkylsilylbis(indenyl) metallocene, wherein the metal is a Group 4 metal and the indenyl is unsubstituted or substituted by one or more substituents selected from the group consisting of a halogen atom, C1 to C10 alkyl, C5 to C15 aryl, C6 to C25 arylalkyl, C6 to C25 alkylaryl, and wherein the metallocene has two leaving groups, X1 and X2, which are both halogen or C1 to C3 alkyl;
• and
• b. the copolymer composition comprises units derived from propylene and ethylene, where the copolymer comprises from about 0.1 to about 20 wt % units derived from ethylene, and:
• i. the density of the copolymer composition is less than about 0.970 g/cc,
• ii. the heat of fusion of the copolymer composition is less than about 75 J/g,
• iii. the melting point of the composition satisfies the relation Tm>−6.2*e +125, where e is the ethylene content of the composition in wt % and Tm is the melting point in degrees Celsius,
• iv. the copolymer is prepared using one dialkylsilylbis(indenyl) metallocene, and
• v. the copolymer composition has a T75−T25 value of less than 35, where T25 is the temperature in degrees Celsius at which 25% of the eluted polymer is obtained and T75 is the temperature in degrees Celsius at which 75% of the eluted polymer is obtained via temperature rising elution fractionation (TREF);
• wherein the Mw of the polymer formed increases or at least does not substantially decrease with increasing monomer conversion at a given reaction temperature.