Process for hydrotreating resins to lighten colour

摘要

The color of hydrocarbon resins having carbon-carbon double bonds and containing color bodies is lightened by a hydrotreating process consisting essentially of contacting a substantially noncrystalline resin with hydrogen at a hydrogen pressure of 1 to 20 bar (14.5 to 290 psi) in the presence of a catalyst that promotes the hydrogenation of the color bodies without substantially changing the softening point or the content of carbon-carbon double bonds in the resin. When the catalyst is nickel/zinc oxide, the catalyst activity for color reduction remains essentially unchanged at chlorine loads up to 4.2% by weight.