Heterogeneous Ziegler-Natta catalysts with fluorided silica-coated alumina

#Polyolefins such as high density polyethylene (HDPE) homopolymer and linear low density polyethylene (LLDPE) copolymer can be produced using various combinations of catalyst systems and polymerization processes. In some end-use applications, it can be beneficial to use a catalyst system having a supported Ziegler-type catalyst component to produce polymers having broad molecular weight distributions (MWD's) and flat or uniform short chain branch distributions (SCBD's). Accordingly, it is to these ends that the present invention is directed.

#This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify required or essential features of the claimed subject matter. Nor is this summary intended to be used to limit the scope of the claimed subject matter.

#The present invention generally relates to new catalyst compositions, methods for preparing catalyst compositions, methods for using the catalyst compositions to polymerize olefins, the polymer resins produced using such catalyst compositions, and articles produced using these polymer resins. In particular, aspects of the present invention are directed to catalyst compositions containing a supported Ziegler-Natta catalyst component. One such catalyst composition can comprise (1) a supported catalyst comprising a fluorided silica-coated alumina, a magnesium compound, and titanium (IV) and/or vanadium; and (2) a co-catalyst. In some aspects, the co-catalyst can comprise an organoaluminum compound. These catalyst compositions can be used to produce, for example, ethylene-based homopolymers and copolymers for variety of end-use applications.

#FIG. 1 presents a plot of the molecular weight distributions of the polymers of Examples 1 and 4-6.

#FIG. 2 presents a plot of the molecular weight distributions of the polymers of Examples 7-8 and 10-11.

#FIG. 3 presents a plot of the molecular weight distribution and short chain branch distribution (SCBD) of the polymer of Example 10.

#To define more clearly the terms used herein, the following definitions are provided. Unless otherwise indicated, the following definitions are applicable to this disclosure. If a term is used in this disclosure but is not specifically defined herein, the definition from the IUPAC Compendium of Chemical Terminology, 2nd Ed (1997), can be applied, as long as that definition does not conflict with any other disclosure or definition applied herein, or render indefinite or non-enabled any claim to which that definition is applied. To the extent that any definition or usage provided by any document incorporated herein by reference conflicts with the definition or usage provided herein, the definition or usage provided herein controls.

#While compositions and methods are described herein in terms of “comprising” various components or steps, the compositions and methods can also “consist essentially of” or “consist of” the various components or steps, unless stated otherwise. For example, a supported catalyst consistent with aspects of the present invention can comprise; alternatively, can consist essentially of; or alternatively, can consist of; (i) a fluorided silica-coated alumina, (ii) a magnesium compound, and (iii) titanium (IV) and/or vanadium.

#The terms “a,” “an,” “the,” etc., are intended to include plural alternatives, e.g., at least one, unless otherwise specified. For instance, the disclosure of “a co-catalyst” or “a magnesium compound” is meant to encompass one, or mixtures or combinations of more than one, co-catalyst or magnesium compound, respectively, unless otherwise specified.