Described herein are alkyl phenolic resins and methods of producing them. The content of residual phenol in the alkyl phenolic resin may be less than about 2% w/w, the softening point of the alkyl phenolic resin may be about 85° C. to about 105° C., the tackiness of the alkyl phenolic resin may be about 8 N to about 25 N, the alkyl group of the alkyl phenol may have 6-12 carbon atoms, and the content of 4-(1,1,3,3-tetramethylbutyl) phenol in the alkyl phenol may be from about 0% to about 85% w/w. The invention also relates to a use of the alkyl phenolic resin as rubber tackifier.