Early History of the Phillips Catalyst

The first chromium-based ethylene polymerization catalyst [1] was discovered by John P. Hogan and Robert L. Banks of Phillips Petroleum Company. On March 4,1958, an historic U.S.Patent 2,825,721was issued to them, and assigned to the Phillips Petroleum Company, in which an olefin 

Product Type Melt Index (MI) (h.J Flow Index (FI) (hJ MFR (FI/Miy Density (g/cc) 

In order to put the discovery of the Phillips catalyst into perspective, it is necessary to discuss the type of ethylene polymerization research that was taking place in the early 1950s. Table 3.2 summarizes the three different ethylene polymerization catalyst systems that were discovered in the early 1950s by three independent research laboratories [2]. 

A paper by Sailor and Hogan [2] provides a very detailed siunmary on the history of polyolefins which includes research reported from 1897-1940 in which linear polyethylene was prepared by various scientists without directly polymerizing ethylene. This early research clearly demonstrated that a linear polymethylene was prepared with a relatively high molecular weight as indicated by a crystalline melting point of 132-134 C. For example, linear polymethylene was prepared by diazomethane decomposition and by hydrogenation of carbon monoxide over ruthenium and cobalt catalysts. 

This paper also provides the chronological details of the three catalyst systems outlined in Table 3.2 in which the Standard Oil (Indiana) catalyst was the first ethylene polymerization catalyst identified [3]. However, as pointed out by Sailor and Hogan, the Standard Oil catalyst was commercialized more slowly than the other two catalyst types, and because of higher operating costs, the Standard Oil process was shut down in 1973. The other two catalyst systems listed in Table 3.2 accoxmt for most of the polyethylene manufactured today. 

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