Process to produce improved poly alpha olefin compositions

摘要

This invention is directed to a two-step process for the preparation of improved poly alpha olefins wherein the first step involves oligomerizing low molecular weight linear alpha olefins in the presence of a single site catalyst and the second step involves oligomerization of at least a portion of the product from the first step in the presence of an oligomerization catalyst. The dimer product from the first oligomerization is characterized by a tri-substituted vinylene olefin content of at least 25 wt %.

主权项

1. A process to produce a poly alpha olefin, the process comprising:
a) contacting a first catalyst, an activator system, and a first monomer in a first reactor to obtain a first reactor effluent, the first reactor effluent comprises a dimer product, a trimer product, and optionally a higher oligomer product, b) feeding at least a portion of the dimer product to a second reactor, c) contacting said dimer product with a second catalyst, and optionally a second monomer in the second reactor, wherein the second catalyst comprises a Lewis acid and is free of a metallocene compound, and d) obtaining a second reactor effluent comprising the poly alpha olefin, wherein the first monomer fed into the first reactor comprises one or more C6 to C24 olefins, wherein the first catalyst is represented by the formula of
X1X2M1(CpCp*)M2X3X4 whereinM1 is a bridging element of silicon,M2 is a metal center of the first catalyst,Cp and Cp* are the same or different substituted or unsubstituted indenyl or tetrahydroindenyl rings that are each bonded to both M1 and M2, andX1, X2, X3, and X4 are independently selected from hydrogen, branched or unbranched C1 to C20 hydrocarbyl radicals, or branched or unbranched substituted C1 to C20 hydrocarbyl radicals; andthe activator system is a combination of an activator and a co-activator, wherein the activator is a non-coordinating anion, and the co-activator is a tri-alkylaluminum compound wherein the alkyl groups contained in the tri-alkylaluminum compound are independently selected from C1 to C20 alkyl groups, wherein a molar ratio of the activator to the first catalyst is in a range of 0.1 to 10 and a molar ratio of the co-activator to the first catalyst is 1 to 1000, and
the first catalyst, the activator, the co-activator, and the first monomer are contacted in the absence of hydrogen, at a temperature of 80° C. to 150° C., and with a reactor residence time of 2 minutes to 6 hours; and wherein the dimer product of the first reactor effluent contains greater than or equal to 50 wt % of tri-substituted vinylene represented by the following structure: wherein the dashed line represents two possible locations where unsaturated double bond may be located and Rx and Ry are independently selected from a C3 to C21 alkyl group.