A polyethylene composition and process for polymerizing the same

Abstract

The instant invention provides a polyethylene composition and process for polymerizing the same. The polyethylene composition according to the present invention comprises the polymerization reaction of ethylene and optionally one or more α-olefin comonomers in the presence of a catalyst system, wherein said polyethylene composition comprises at least 2 or more molecular weight distributions, measured via triple detector GPC low angle laser light scattering (GPC-LALLS), described in further details hereinbelow, wherein each molecular weight distribution has a peak, and wherein measured detector response of peak 1 divided by the measured detector response of peak 2 is in the range of from 0.50 to 0.79, for example from 0.55 to 0.77.

We claim: 
     
         1 . A polyethylene composition comprising the polymerization reaction of ethylene and optionally one or more α-olefin comonomers in the presence of a catalyst system, wherein said polyethylene composition comprises at least 2 or more molecular weight distribution, measured via triple detector GPC low angle laser light scattering (GPC-LALLS), wherein each molecular weight distribution has a peak, and wherein measured detector response of peak 1 divided by the measured detector response of peak 2 is in the range of from 0.50 to 0.79. 
     
     
         2 . A process for polymerizing a polyethylene composition comprising the steps of:
 (A) Preparing a slurry of a precursor and a viscous inert liquid, said slurry having a viscosity of at least about 500 cp, the precursor comprising (i) a ligand; (ii) a transition metal; and (iii) a first Lewis Base;   (B) Contacting the slurry of (A) with a first Lewis Acid such that at least a portion of the Lewis Base is complexed with the Lewis Acid wherein the Lewis Acid has the formula MR n X (m-n) , M is Al, B or Si, R is a C1 to C14 alkyl or aryl radical, X is Cl, Br or I, m+n satisfies the valency of the metal M, n is 0 to 3;   (C) Contacting the slurry of (B) with a second different Lewis Acid with the formula MR n X (m-n) , M is Al, or B, R is a C1 to C14 alkyl or aryl radical, X is Cl, Br or I, m+n satisfies the valency of the metal M, n is 0 to 2;   (D) Feeding the slurry of (C) into a gas phase reactor in which an olefin polymerization reaction is in progress optionally in the presence of one or more cocatalysts and wherein the molar ratios of Lewis Acid 1 and Lewis Acid 2 to the electron donor are controlled to affect specific fractions of the molecular weight distribution of the final polymer product;   (E) Where both the relative ratio of Lewis Acid (1) and Lewis Acid (2) to internal electron donor and the chemical identity of Lewis Acid (1) and (2) is adjusted to polymerize said polyethylene composition, wherein said polyethylene composition comprises at least 2 or more molecular weight distributions, measured via triple detector GPC low angle laser light scattering (GPC-LALLS), wherein each molecular weight distribution has a peak, and wherein measured detector response of peak 1 divided by the measured detector response of peak 2 is in the range of from 0.50 to 0.79.   
     
     
         3 . An article comprising the polyethylene composition of  claim 1 . 
     
     
         4 . The article of  claim 3 , wherein said article is produced via rotational molding, thermoforming, blow molding, or injection molding. 
     
     
         5 . The process for polymerizing a polyethylene composition according to  claim 2 , wherein the process occurs in a single gas phase reactor, or a dual gas phase reactor.