Such synthetic hydrocarbon tackifiers generally have ring and ball softening temperatures of about 10??? C. to about 100??? C. The polycarboxylic acid ester tackifier resins are polymerized from one or more monomers such as acrylic acid which is substituted or unsubstituted with alkyl or alkoxy radicals having one to four carbon atoms or with alkyl or alkanol esters of such acids in which the alky