based resins may be characterized as having the general formula str2 where the rings 2 and 3 can be either saturated or unsaturated as revealed in the following structures str3 and mixtures thereof wherein r 1 and r 2 are independently h or an alkyl group containing from 1 to about 4 carbon atoms with methyl preferred x u2550 r n 39 ch 2 oh r n 39 cooh nh 2 or r n 39 ch 2 ococ 6 h 4 cooh wherein n is of an integer being a value of 0 or 1 x may also be any group reactive with a group providing vinyl functionality the preferred precursor resins of this invention are those having the structures 6 7 or 8 as well as a mixture thereof the most preferred precursor resins used in this invention are abitol rosin amine and rosin acid which have the respective structures str4 as conventional wherein the group occupying the pendant lines are methyl another class of precursor resins which can be used in the present invention are rosin esters formed by the partial esterification reaction products of any of the structures having carboxyl functionality with polyols where the reaction product contains residual hydroxyl groups for further reaction to add a vinyl functional group the polyols which can react with rosin acids include among others str5 and the like where m and p independently have a value of from 1.