Comprising at least one aromatic monomer and at least one repeating unit of the acrylate monomer, the residual mono monomer concentration is low, tackifying resin is provided. In another embodiment of the present invention, the tackifying resin is not significantly decrease the moisture transport rate of the adhesive composition containing it, significantly increase the haze of the adhesive composition comprising the tackifier resin significantly it does not show and the skin sensitization not. Manufacturing method of the tackifier resin is also provided. The method, and at least one carrier and the tackifier resin product stream at a temperature sufficient to remove at least a portion of at least one residual monomer from the tackifier resin product stream, tackifier into contact It comprises generating the resin.