摘要 |
<p>Hydrogenated random block conjugated diene/monovinylarene copolymers with a terminal monovinylarene block having a diene content in the range of 44 to 70 weight percent, normalized vinyl in the range 30.2.-51.3 percent, percent vinyl based on copolymer plus percent styrene in the range 59.8-71.5 percent, and molecular weight M<Sub>n</Sub> in the range 94,000-199,000, used as viscosity index improver in lubricating oil, exhibits unusually high thickening power, yet provides viscosity index, pour point, and shear loss at very desirable levels.</p> |