| 摘要 |
PROBLEM TO BE SOLVED: To provide high viscosity PAOs that have very small portions of high molecular weight molecules and are very shear stable.SOLUTION: A polyalphaolefin polymer having a kinematic viscosity at 100°C of 135 cSt or greater is shear stable. The polymer includes 0.5 wt.% or less of the polymer having a molecular weight of greater than 60,000 dalton or, after being subjected to 20 hours of taper roller bearing testing, the polymer has a kinematic viscosity loss of less than 9%. Such a shear stable polyalphaolefin is obtained by either mechanical breakdown of a high viscosity polyalphaolefin or by a selective catalyst system used in oligomerization or polymerization of feedstock. |
