resin modifier

Phenolic resin modifier for wet curtain paper and phenolic resin for wet curtain Provided are a modifier for polyolefin resin which imparts excellent wettability for water, etc. to a polyolefin resin substrate without decreasing the resin property of the polyolefin resin substrate composed of polyolefin resin, and a polyolefin resin composition containing the modifier and a polyolefin resin. The present invention relates to a modifier for polyolefin resin (K) containing polyolefin (A) and unsaturated dicarboxylic acid (anhydride)(B) as a constitutional unit, and a copolymer (X) having an acid value of 50 to 250 mg KOH/g.