Maleated liquid C5 hydrocarbon resins

This invention relates to functionalized hydrocarbon resin compositions having similar physical properties as natural rosin and to methods for their preparation. More particularly, this invention relates to acid-modified liquid C hydrocarbon resin compositions prepared from piperylene and unsaturated carboxylic acids or anhydrides and their use as an alternative to natural rosin. Acid modified Chydrocarbon resins are disclosed. The resins are predominantly piperylene resins with isobutylene. The resins are acid modified with from about 0.1 to 30 weight percent maleic anhydride to provide an acid-modified resin with a acid number from about 30 to about 170 mg KOH/g resin. The acid-modified resins have a mettler drop softening point from about 40° C. to about 140° C. The acid modified resins are useful as a natural rosin alternative.