Adhesive composition and adhesive sheet using same

Provided is a water-dispersible adhesive composition having excellent re-peelability and water resistance, and having a high biomass degree. A water-dispersible adhesive composition containing a (meth) acrylic copolymer obtained by emulsion polymerization of a monomer mixture in the presence of an anionic emulsifier, the monomer mixture containing 1-99 parts by mass of a monomer (b1) below and 1.0-10.0 parts by mass of a monomer (b2) below, the biomass degree of the water-dispersible adhesive composition is 10% or more. (b1) at least one monomer selected from the group consisting of n-octyl (meth) acrylate, 2-octyl (meth) acrylate, lauryl acrylate, lauryl methacrylate, stearyl acrylate, myristyl acrylate, myristyl methacrylate, cetyl acrylate, cetyl methacrylate, and stearyl methacrylate derived from a biomass raw material; and (b2) at least two copolymerizable monomers having carboxyl groups. 本申请提供一种再剥离性和耐水性优异、并且生物质度高的水分散粘合剂组合物。一种水分散粘合剂组合物，其含有通过在阴离子性乳化剂的存在下的单体混合物的乳液聚合而得到的(甲基)丙烯酸系共聚物，所述单体混合物中，下述单体(b1)的含量为1～99