Light-colored rosin and rosin ester compositions

摘要

A three-step method to prepare a light-colored rosin ester is disclosed wherein at least in one of the steps (a) and (c) a co-catalyst is applied and wherein at least in one of the steps (a) and (c) a disproportionation catalyst is applied. In the second step, a distilled rosin is obtained which is esterified with a polyol into a light-colored rosin ester. In one embodiment, the co-catalyst has a triplet formation quantum yield (ϕ_T) of greater than 0.5 and a triplet lifetime (τ_T) of greater than 0.5 microseconds. In another embodiment, the co-catalyst is selected from acridone, anthrone, 9-fluorenone, thioxanthone, xanthone, derivatives and combinations thereof.