OLEFIN POLYMERS, METHOD OF MAKING, AND USE THEREOF

摘要

The present invention is directed to homo-polymers and copolymers of mono-1-olefins, a method of making such polymers, and uses of such polymers. Polymers of the present invention are formed by contacting at least one mono-1-olefin having from 2 to about 20 carbon atoms per molecule and at least one mono-l-olefin co-monomer having from 2 to about 10 carbon atoms per molecule in a reaction zone under polymerization conditions in the presence of a hydrocarbon diluent, a catalyst system, and a cocatalyst. The catalyst system of the present invention comprises a chromium source on an aluminophosphate support which has a phosphorous to aluminum mole ratio of less than about 0.3. Further, the catalyst system is treated with less than about 7 weight percent fluoride based on the weight of the support and is calcined. Cocatalyst are selected from trialkylboron compounds, triarylboron compounds, alkylaluminum compounds, and combinations thereof.In another aspect of the present invention, ethylene copolymers are employed to produce PE-100 pipe. These copolymers are formed by contacting ethylene with at least one mono-l-olefin comonomer having from 2 to about 10 carbon atoms per molecule in a reaction zone under polymerization conditions in the presence of a hydrocarbon diluent, a catalyst system, and a cocatalyst. Additionally, the comonomers may be selected from mono-1-olefins having 4 to 10 carbon atoms, such as, 1-hexene, 1-butene, 4-methyl-1-pentene, 1-octene, and 1-decene. Further, these ethylene copolymers may be employed to produce PE-100 pipe having both small diameters and diameters in excess of 42 inches substantially without sagging or other gravitational deformation. Copolymers of ethylene and 1-hexene are disclosed which are used to produce PE-100 pipe.