Business and Technology of the Global Polyethylene Industry: An In-depth Look at the History, Technology, Catalysts, and Modern Commercial Manufacture of Polyethylene and Its Products

Chapter 4

Single-Site Catalysts Based on Titanium or Zirconium for the Production of Polyethylene

4.1 Overview of Single-Site Catalysts

The introduction of single-site catalysts for the manufacture of polyethylene is the most recent catalyst innovation that has taken place in the polyethylene industry, with this type of catalyst introduced on a commercial scale in the late 1990s. Single-site catalysts have created new types of polyethylene for the polyethylene industry in which new grades of polyethylene have been introduced into new markets and applications. For the most part, single-site catalysts have not eliminated any other catalyst system from commercial production. These catalysts have primarily expanded the polyethylene industry into new markets.

4.1.1 Expanded Polyethylene Product Mix

Until the mid-1990s, the polyethylene product space consisted of the manufacture of ethylene-based homopolymers and copolymers over a density range of about 0.910–0.965 g/cc with Melt Index values (MI_2.16Kg) between about 0.05–100.

The introduction of single-site catalyst technology has expanded the polyethylene product space to densities as low as about 0.86 g/cc with traditional comonomers such as 1-butene, 1-hexene and 1-octene. In addition, single-site catalysts have provided new ethylene-based copolymers with comonomers based on styrene and cyclic olefins such as norbornene.

4.1.2 Types of Single-Site Catalysts

There are primarily three types of single-site catalysts used to manufacture ...